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trouts2




Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1275

Small engine repair questions, Tecumseh HSSK50
Original Message   May 19, 2008 9:37 pm

  I’ve got a few questions on rebuilding a small engine.  The engine is a Tecumseh HSSK50 67366S.   I think the model year is 1998.  It came off an MTD Gold 526 snowblower and had a broken rod.  The exploded parts view is here:

 

http://www.outdoordistributors.com/pdf/Tecumseh/TECUMSEH-MODEL-HSSK50-67366S-PARTS-LIST.pdf

 

   I’m just experimenting to see what’s involved with doing some repair on engines and this engine was broken and free so a good candidate.  If I mess it up in learning it won’t be much of a loss. 

 

Question 1:

  After taking off the head I tried to move the piston back and forth with my fingers.  It seemed tight and did not move from side to side.  The reading I’ve done says to measure the space at the wall.  I assume they meant the ring to wall distance and not the piston to wall distance. 

    They mentioned taking a reading of the gap but did not say how to do that.  How do you take a measurement of that distance? You can’t use thin flat sparkplug feelers as they’re too stiff to bend with the wall shape.  They would press out so not give an accurate feel.  How do you measure the ring to wall gap?

 

Question 2:

   What are acceptable limits for the gap?

 

Question 3.

   I don’t have a dial gauge that can take an inside reading of the cylinder.  I have dial calipers but I don’t think they would be accurate enough.  There may or may not be a ridge at the top of the wall so the calipers would read the ridge and not be able to get deeper.  Is there a way around this without having a special gauge for taking the reading?

 

Question 4:

   Given that I don’t have gauges for an inside wall measure would it be unreasonable to assume a 10 year old motor would be worn and just put in .010 oversized rings?  Lightly hone out the cylinder wall and go with .010 rings? 

   Just say the motor was lightly used and the wall in excellent shape.  Would putting in .010 rings cause problems by being too tight?

 

Question 5.

   On opening up the case I looked for timing marks.  I think one is a hole in the cam gear.  I did not move anything before taking out the crank and cam.  I could not find another mark on the crank gear to mate with the hole in the cam gear. 

   I should have made some scratches but did not for some reason.  I think I got a phone call and forgot when I got back.  Does anyone know the marks on this engine?  My reading said to look for a raised dash or one of the teeth on the crank gear to be beveled.  I could not find either or any other mark.  How can I get the alignment right?  I could put it back together with the case open and hand turn the crank and watch the valves but I think I might be off a tooth or two doing it that way. ??

 

Question 6:

    The crank journal (the place where the piston gets bolted to the crankshaft) looks shiny and without scratches.  The piston and rings look undamaged.  The valves and tappets look fine.  There is no place inside that seems to have gotten hit by the broken rod end or the broken bottom part.  The only place that got scratched was on the crank.  That was big bulging part I think is a counter weight for the crank.  It got scrapped quite a bit over a few inches but I don’t think there’s been enough metal removed to make a difference in weight so seems like that damage would not factor in. 

   Given that all the parts seem ok if I were to bypass putting in rings the minimum repair would be putting in a new rod and at least cleaning and lapping the valves.  The minimum job would be doing that and putting everything back in and torque what ever needs to be touqued.   Does that sound right?

 

trouts

Replies: 1 - 25 of 25View as Outline
friiy


Location: Las Vegas, The Desert
Joined: Apr 12, 2008
Points: 599

Re: Small engine repair questions, Tecumseh HSSK50
Reply #1   May 19, 2008 11:59 pm
Qustion #1  ????????  

  I have measured ring gap,  (the distance the ends of a ring come together. in the cylinder.)

 I have measured  piston ring groove gap (the slop in the ring groove of the piston with the ring inside)

Question  #2  Depends on the wich one you are talking about..   Most of these limits do not matter in most rebuild cases..

                          Lots of engines fail do to neglect and and have catastrophic failure..  They do not run 20 years 4 hours a day then throw a rod.

Question #3    T- shaped telescoping gage  (They only have a Small range so you have to use one about the size you expect,  1/2 " inch range if  Iremember). use it along with your micrometer.

Question #4   I would think you would want to go with standard size chrome service rings,  they have better oil control than standard on a motoer you are not going to machine oversize.  Oversized rings in a engine that has not been oversized would not go together easy if at all,  you would most likely break a ring or tear up the cylinder wall trying to get it together.  IF it was able to be started it may have too much friction and over heat..

Question #5  There Has to be some kind of mark,  one way to help  find TDC is to take the flywheel or the engien keyway and aline it with the spark plug  at 12' oclock. 

  I have not heard of RAISED DOT only dash marks, dimpled in or beveled gear teeth.  if you found ONE mark on the cam or crank, the other gear will have TWO marks. (the one mark fits between the two marks)      

Question #6  The rod Journal is almost bullet proof,  When someone runs a engien out of oil and throws a rod ,   the rod starts to get hot (lack of lube) and starts to melt on the crank, this is a lot of friction and resistance to the piston forcing the rod down the rod can not handle this kind of load,   and the rod snaps in the thinner spot (most of the time). the solf aluminum rod does not damage the crank when this happens,  but it does smear aluminum on the crank journal simetimes like a crayon on a hot sidewalk....     Does your Crank journal shine or is it dull?   If it is dull it may be worn (maybe fromsomeone not changing the oil),  a Dull crank is worn by grit in the oil embedding itself in the soft aluminum of the rod, this inturn slowly grind down the crank and produces a slight knock from crank wear.  Long story short, if the crank is shiny it is normally good,  But if you like you can mic it out.

Now here is how I would check this motor out.

#1 no holes or cracks in the case? No gouges in the cylinder wall where the rings pealed back the aluminum?

#2 Is there a bunch of carbon on the head?  I am not talking about a dusting or a small skin of carbon on the head or piston..  I am talking about 1/8 inch or deeper carbon deposit.  (Idont want a good running engine that smokes.. (If i can smell oil burning under high load I will live with it as  long as it makes power. and I am not SEEING any white smoke and fogging mosquitoes)      

#3 how bad is the cylinder ridge? can I see the origanal bore pattern?  IF I CAN RUN MY FINGERNAIL ON THE BORE RIDGE AND FEEL IT BUT IT DOES NOT TRY TO RIP THE FINGER NAIL OFF AS I CROSS IT. 

friiy


Location: Las Vegas, The Desert
Joined: Apr 12, 2008
Points: 599

Re: Small engine repair questions, Tecumseh HSSK50
Reply #2   May 20, 2008 12:26 am
Sorry, Wireless keyboard locked up as I was typing and went into all caps....

Well,

I would check the valves at full open, I would see if there was any excessive wobble in them.. (checking for bad or worn valve guides)

Also check the looke of the stems when you have them out..  (check them for a wear on the stem, like a a ridge at the travel limits where they ride in the guides).

Check the piston pin for the same effects and wear as you would a crank journal.

Look at the oil residue in the engine case,  Is it grey and shimmer like aluminum putty?

My bet is the engine only needs a rod and a rinse out with solvent  (seals and gaskets also).  But if you are in there you may depending on wear, install rings.  I wouldn't change the piston unless i found other things wrong with it.

I believe this engien was running strong when it threw the rod, or it was worn out.   (is there thick carbon?, aluminum putty or grit in the / oil residue, do the valves rock far back and forth? does the engien have a groove on the cylinder wall that would make me stub my toe?)

It comes down to one or the other:  Did it die a slow death and the rod was the final straw over 10 years of heavy use or did it seize the rod from a one time event of low oil?

Good Luck,

Friiy

P.S. If you are truely trying to learn, I would just clean it , put a rod in , then see how it works.   Put it back together and see if it has problems.  Watch results as each problem (if it has any) is resolved one at a time. 

niper99


Location: London Ont
Joined: Dec 2, 2007
Points: 333

Re: Small engine repair questions, Tecumseh HSSK50
Reply #3   May 20, 2008 1:48 am
hey troust2

first thing filly gave some really good adivce , as far as checking to confrim if u have the correct timing question #5 when u have the cylinder head off and the valves are back in turn the engine over and watch the valves too see if they both open slightly at the same time (exhuast stroke ending/ intake stroke starting). if u have an engine that has the head off u can check it and see what l'm talking about.

good luck on rebuild

This message was modified May 20, 2008 by niper99
trouts2




Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1275

Re: Small engine repair questions, Tecumseh HSSK50
Reply #4   May 20, 2008 9:30 pm
friiy and niper99

The case was looked over before and seemed ok but today when doing the detail cleaning of the last drops of oil I noticed a gouge on the inside case wall. On the outside there was a hairline crack about an inch long with a very slight bulge. I put water on the inside and it leaked through so I assume the block is hosed.

So much for that one but I might try putting what's left back together for practice.

I've got 3 other bogus engines. Another 70's 5hp with a broken rod and two older 7hp's. The 7hp's are the ones I really would like to fix and the 5's practice engines.

The 7hp's push oil so still functional. One has 90psi but pushes droplets of oil out the breather. The other does not push oil until it's run for a while and then under load. At that point it gushes oil. The breather mesh filters on both of those are clean so I suspect rings or valves on those.

The goal was to get familiar with things on the 5hp then do the 7's. The first 5hp is out. I might as well take the second 5hp with a broken rod apart as practice and if it's in good enough shape put a rod in that one. If that goes well then work on the 7's.

Thanks for all the information and suggestions. It's excellent reference information and will help quite a bit on the next engines.
trouts2
This message was modified May 20, 2008 by trouts2
friiy


Location: Las Vegas, The Desert
Joined: Apr 12, 2008
Points: 599

Re: Small engine repair questions, Tecumseh HSSK50
Reply #5   May 21, 2008 11:46 am
Hey Touts,

There realy is not any structure to the area of the brake/crack all the load is in the webbing of the case where the crank fits through.

I would   "stop drill"  the cracks of case and fill in with a good epoxy.

God Luck,

Friiy

I have some great aircraft struckure epoxy called 1830g, If you like I will send you some.

trouts2




Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1275

Re: Small engine repair questions, Tecumseh HSSK50
Reply #6   May 21, 2008 6:32 pm

   Thanks for mentioning the epoxy.  I just might do that.  The engine looks-wise is in excellent shape.  There’s no rust rash around the head bolts and the cowling and recoil look new.  I looked pretty close at the insides and I think the damage is only in that one spot. 

 

   The other 5hp was taken apart today.  It also had a broken rod.  The case on that one looks intact.  There’s one gouged spot but no sign of puffing out the case or cracks.  The crank journal on this one is all chewed up and the piston skirt off in chunks.  From what I’ve seen so far the case should be salvageable but would require at a minimum rings, piston and rod.   I just finished up taking it apart so tomorrow will do the refined cleaning and take a better look at everything.

 

   I compared the piston on both 5hp’s, the newer 5 versus the older 5.  The new 5 had a larger diameter piston.  Its rings were not as thick.  Its piston skirt was not very long and the bottom cut parallel to the piston top surface.  The older piston had the skirt extend down past where the new one was cut off as in an extended v in two places.  The cross pin that holds the rod was smaller than the older pin and on the new piston inset into the side diameter so less metal in the pin and less in the piston body.

    So the newer piston was larger diameter but less overall metal so lighter.

 

    The cranks were also different.  I’ll try to post a picture.  The newer one was shorter and lighter.  The cam gear was much smaller on the new 5 and the counter weights also much smaller. 

 

    Given all that extra weight rotating at 3600 rpm there’s got to be more torque in the older motor.

 

     The older 5hp came on a Jacobson Imperial 526 which is an odd size these days.  It might be nice to get this one working again.  The engineers should have sized a motor capable of good performance so I expect this engine if in good shape might toss snow well. 

   The body paint is all gone and the machine completely covered in surface rust but the metal all solid.  The tractor insides are unworn and tight.  The friction disk looks new and unused.  It’s wider than any I’ve ever seen and thicker than either Ariens or Toro rubber from the 70’s.  The scraper bar seems original and without wear.  It would be nice to see this thing run so maybe I’ll give this motor a shot if there’s nothing else wrong with the motor.

     The cams were compared and the cam from the older 5hp is significantly heavier than the newer 5hp crank. 

    The engines are covered with dirt and oil so pretty messy and not so easy to clean.  Below is the poor man's cleaning tank made up this morning for cleaning the 5hp.  It's a 5 gallon plastic gas can with the top cut out as a splash shield.  Put the parts inside which get cleaned with gas and a paint brush.  When done the gas is poured back into a spare 1 gallon gas can for reuse later.  The dirt and grime left on the bottom is cleaned out with a rag.  It worked out pretty well.  The parts get clean with only a film of oil and gas which cleans off easily with warm water and soap.

trouts2
This message was modified May 22, 2008 by trouts2
friiy


Location: Las Vegas, The Desert
Joined: Apr 12, 2008
Points: 599

Re: Small engine repair questions, Tecumseh HSSK50
Reply #7   May 23, 2008 12:13 pm
Hey Trouts2,

The epoxy I was talking about is 1838 b/a green by Scotch-weld...good stuff..

Your 7 hp that blows oil from the breather may have a problem with the ring gap.

I have seen rings that spun in their groove and lined up with each other,  meaning that compression and exhaust blowby is maximized,  or you may have a compression ring that has stuck (carboned or seized ) in the groove compressed (making it in-effective)

OR... you may have a breather assy. that the reed valve is loose or stuck part open.  (try swapping with another breather assy.)

If you need piston/ ring assy. on a TEC. motor.   I like to use the aftermarket company Rotory Corp.  for those kits.   they made taking in older engines that need rings more cost effective for repair.

Good Luck,

Friiy

trouts2




Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1275

Re: Small engine repair questions, Tecumseh HSSK50
Reply #8   May 24, 2008 10:10 pm

Friiy,

 

   I don’t want to trouble you with mailing the epoxy.    I located several places that sell 1838 but their lowest quantity is one “kit” composed of 6 kits of 6 sets of epoxy and hardener.  I will eventually use up 6 sets but not 6 kits of 6 sets.  One place is checking to see if they can send one “kit” of 6 sets and will get back to me on Monday.  I’ll probably give the 5hp with the cracked case a shot.

    The Rotary company  requires an account before they’ll give me a login so I’ll get in touch with them on Monday.  

 

    The second 5hp is out of the running for a scored crank, broken piston and rod. 

 

   Today I opened the7hp and it’s looking good.  It gushed oil so the parts are good.  The opening went a little smoother so I recorded the positions of the crank, cam and rod retainer and took pictures.  The push rods were taped and marked with their positions.

 

   The ring alignment was ok I think.  The top ring gap was at about 7-8 o’clock, the second ring at 3 o’clock and the oil ring at 5 o’clock.  

 

   The breather is confusing.  When I check the breathers on engines I look for the round cover to move in and return to the cover plate.  I’ve never had one stuck or not return to the plate but I never know if it’s sealing 100% or not.  Is it that critical to have 100% seal?  Is it internal pressure that closes it?  Anyway the ones I’ve checked in the past seemed to be closing and without obstructions preventing full closing and it’s like that on this 7hp. 

 

   The rings moved freely in their groves so ok, no carbon caused sticking.

 

   The piston looks fine and no scoring on the cylinder wall.  There is a black spot on the wall that was a surprise.  It’s looks like a burn stain as opposed to carbon buildup.  There was a good size lip of carbon at the top of the cylinder and 1/8th of an inch of carbon on the piston top.  The carbon buildup at the top came off with a lot of scrubbing with Oak wood chips but the black stain remained.  I’ll post a before and after picture. 

  

   So the questions are:

   Does the breather cover close air tight or just come up against the cover?

 

   Is the black spot just a stain or indicate something worse?

 

   The pictures show dark areas extending around the exhaust valve under the area of the gasket. It’s seems to be a leak but must have been small as I did not notice any smoke from that area.  There was a bit of smoke from the muffler so maybe it masked smoke from a gasket leak.  ?? Does that look like a leak?

    Just did some quick price checking on the net.  A ring set is $12 and a rod $27.  The rings should be replaced as a given but the rod and it's bottom retaining part look fine.  Would it be brain dead not to replace the rod even if it looks fine?  I was thinking of a minimum job of rings and lapping the valves so iffy about a new rod or even a piston.  What's usually done?

trouts

This message was modified May 24, 2008 by trouts2
friiy


Location: Las Vegas, The Desert
Joined: Apr 12, 2008
Points: 599

Re: Small engine repair questions, Tecumseh HSSK50
Reply #9   May 25, 2008 10:25 am
That engine looks like it burns a little oil...

The black spot is just a hot spot on the cylinder wall next to the exhaust valve,  a little burned/ glazing oil there.. (just break it up if you hone the engine).     

I have seen people bust the breather by sticking their finger in the hole and bending the reed valve out of limits.

the rod I check by checking for a knock when its running under heavy load, if the engine is apart I torque the rod to the crank and check for play. I would not change the rod unless I found a problem.

The staining of the case around the valves where the head gasket sits is a leak,  sometimes the engine will make a "chirping noise" when cold, the chirp sometime goes away wen the engine heats up, but the leak is still there..

Rotory is a dealer supplier, if you can find a dealer  you may be able to save a little more.

Your 5 hp with the scored crank,  I bet 50/50 the crank is good,  the crank likely has aluminum melted on it, (kinda like crayon wax on a smooth wood table).  the way to remove it without damaginge the crank is to use pool acid (muratic acid....spelling?)..   take  a Q-tip and dip it in the acid and wipe it around the area of the crank surface, if it is  aluminum, the area will turn grey and bubble, repeat until clean and smooth.   Do not let the acid stay on the metal any longer than needed.  Overnight acid will start to cause surface rust  (even the fumes),  so apply the acid by hand,  rinse with water, then spray the crank with  oil or wd-40 to displace water and prevent rust.

If they wan't to sell you only packs of 6, let me send you one pack and you can see if you like it.. (epoxy). Email me with your info/address

Good Luck,

Friiy

trouts2




Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1275

Re: Small engine repair questions, Tecumseh HSSK50
Reply #10   Jun 4, 2008 8:52 pm

Friiy,

   I finally got around to picking up some Muriatic acid and working off the aluminum smudges on the older 5hp crank.  It’s looking pretty good and I think smooth enough to be used again.  I can’t feel any bumps or depressions or see any imperfections.  It got a light finish sanding with 600.  Thanks for suggesting the process.  I thought it was unsalvageable after first looking at it.

  

   The above motor requires a rod, rings and piston so somewhat expensive.  There are two other motors here waiting for parts and tools which I’ll probably try first.  A newer 5hp which needs rings and rod and a older 7hp which just needs rings.  The experiment candidate is the newer 5hp so if I goof up it will be less expensive. 

 

  By the way the newer 5hp crank weighs 3.69 and the old 5hp 4.77.  Quite a difference. 

 

  The rest of the parts and tools should be in by the end of the week so maybe in two weeks I’ll have a couple engines done and tested. 

trouts
trouts2




Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1275

Re: Small engine repair questions, Tecumseh HSSK50
Reply #11   Jun 8, 2008 8:46 pm

Stumped again.

 

   The original ring set has been replaced with a new set that adds some features.  The old compression ring did not have an internal notch or bevel on either ring.  The new compression ring does.  That seems ok.  The oil wiper ring (second ring) has a stepped notch on the outer face and that also seems ok.  Both match the book I got from the library but the original old rings don’t (no bevels or notches on either ring).  I think the new set is Tecumseh’s updated replacement set and ok.  The ring set is 40006.

 

    The problem part is the third ring.  It’s a very different design that the old ring.  The old ring was one piece with cutouts for wiped off oil to go to the crankcase.   There’s an expansion ring behind it.  The new ring is a very different design with a top and bottom ring and also a spring ring that goes between them. 

 

    What I’m not sure about is if the new design eliminates the need for the expansion ring.  There are two issues. 

1.       Should the expansion ring be used with the newer style oil return ring (third ring)?

2.      If it should be used, given it’s age and I think spring steel then is it always replaced or just used again?

 

   It’s confusing because the way my book reads the expansion ring is something that would be inserted when the motor was getting old and the oil return ring might need some help being pushed out.  I did not expect to find one in a motor that had never been opened before. 

trouts

friiy


Location: Las Vegas, The Desert
Joined: Apr 12, 2008
Points: 599

Re: Small engine repair questions, Tecumseh HSSK50
Reply #12   Jun 9, 2008 12:49 am
Hey Trouts,

You should not have to use any rings or ring parts over again.   The new rings are just better for oil control and completely diffrent..    Did they send a picture or piece of paper showing the correct orientation of the new rings? 

Be sure to clean the ring grooves if you reuse the old piston (a piece of a old ring ,ground flat , to drag throught the groove and remove carbon).  Be sure to put the piston and rod back in its original orientation.   If you did not mark them, check that PDF file that Dennis put  a link to. 

Good Luck,

Friiy

trouts2




Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1275

Re: Small engine repair questions, Tecumseh HSSK50
Reply #13   Jun 9, 2008 1:30 pm
  The ring set was a Tecumseh set and did not have any paperwork in the package.

   The manual you mentioned I think was the Tecumseh 3-11hp engine manual.  It has a good explination of the bevels and notches and their orientation on the piston.  The compnents have been cleaned up so ready to install. 

trouts

trouts2




Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1275

Re: Small engine repair questions, Tecumseh HSSK50
Reply #14   Jun 13, 2008 9:42 pm

  Got it back together but it won’t fire up.  On the first pull it gave one cough and belched some smoke and would not fire again.  I took the head off and there was oil on the gasket, block and head surfaces by the gasket.

 

   The gasket looked good and the head flat except for some slight curl at the very edges of the head and block.  I fine filed those off and the head and block seem flat – at least with the straight edge I have held to the block against a light. 

 

   I buttoned it up, torqued the bolts to 200, and putting some talcum powder around the block and head joint.   On pulling the start rope it blew away the talc at the gasket at the middle side head bolt.  The head must be warped.  It leaks from the side.

 

   The engine had a broken rod so ran before the parts were installed.  All I can think of is the rod must have pushed the piston into the head.  There’s no sign of any contact though so puzzling how the head or gasket could leak.  ?? 

 

  1. Is it common that a head would be warpped after a rod breaks?
  2. Getting it machines would be to expensive.  Is it possible to get it within service tolerance (what ever that is) by hand?  Can it be flat filed or ground on a flat plate.  A friend made a plate for me 17 x 17 inches flat across the diagonal to a 10 thousandth.  The gasket seems to hold at the valve and cowling ends but bowed up in between. 
  3. How can I deal with this?
trouts
niper99


Location: London Ont
Joined: Dec 2, 2007
Points: 333

Re: Small engine repair questions, Tecumseh HSSK50
Reply #15   Jun 13, 2008 11:31 pm
trouts2 wrote:

  Got it back together but it won’t fire up.  On the first pull it gave one cough and belched some smoke and would not fire again.  I took the head off and there was oil on the gasket, block and head surfaces by the gasket.

 

   The gasket looked good and the head flat except for some slight curl at the very edges of the head and block.  I fine filed those off and the head and block seem flat – at least with the straight edge I have held to the block against a light. 

 

   I buttoned it up, torqued the bolts to 200, and putting some talcum powder around the block and head joint.   On pulling the start rope it blew away the talc at the gasket at the middle side head bolt.  The head must be warped.  It leaks from the side.

 

   The engine had a broken rod so ran before the parts were installed.  All I can think of is the rod must have pushed the piston into the head.  There’s no sign of any contact though so puzzling how the head or gasket could leak.  ?? 

 

  1. Is it common that a head would be warpped after a rod breaks?
  2. Getting it machines would be to expensive.  Is it possible to get it within service tolerance (what ever that is) by hand?  Can it be flat filed or ground on a flat plate.  A friend made a plate for me 17 x 17 inches flat across the diagonal to a 10 thousandth.  The gasket seems to hold at the valve and cowling ends but bowed up in between. 
  3. How can I deal with this?
trouts


trouts

did u check compression?, is the head gasket new or old ? l personally have never seen a head warp badly enough that a new head gasket wont fix.

friiy


Location: Las Vegas, The Desert
Joined: Apr 12, 2008
Points: 599

Re: Small engine repair questions, Tecumseh HSSK50
Reply #16   Jun 14, 2008 1:32 am
I have never seen a head warped to care about.  

Do you have a piece of the old gasket stuck on the edge somewhere?

Are all the bolts for the head the same size?  Sometimes there are three or more bolts longer around the exhaust valve too draw and dissipate heat in the block.. If these bolts are installed in the wrong spot they may bottom out before tightening the head.  Also are your threads clean in the block?  Maybe you are trying to drive these bolts into dirty packed treads  (  burned up oil grissle)  not really seating against the block with the gasket...

Are you using a old gasket?  The lead plate head gaskets seal great, but are one use only,  ridgid Gaskets with the tin sometimes burn through..

The new gasket sould be able ,I imagine, to take up .025 " easy,   they are very thick..

All I ever did was clean the head and block surface with scochbrite to take the carbon/ old gasket pieces off... I never cared to even too see one warped,  (it never mattered,  the gasket always held...)

Later, Good Luck ...   I gotta go back to work,   Gotta broke RB211,  need to look up parts.

Friiy 

trouts2




Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1275

Re: Small engine repair questions, Tecumseh HSSK50
Reply #17   Jun 14, 2008 2:33 pm

   The flywheel key was broken and the flywheel at exactly 180 out.  After testing since it was 180 out I figured I had the cam in wrong.  On starting to unbutton the engine I found the broken key. 

 

   After putting in a new key it starts, runs and seems to be fine except it runs away.  The governor is not kicking in.  I don’t know how that can be as there’s only an arm and I think it just butts up against the wheel weights. 

   The arm is toward the inside of the case which I think when under spring tension would snug the arm against the governor wheel on the side towards the back of the case.  ?? So I’ll have to check what up there. 

 

   It seems like the arm is not being moved so possibly on installing the cam the arm got out of place and toward the cover side of the engine but if that were the case the outside part of the arm would almost hit the carb the way things are setup on this motor.   It could be I have the linkage positions wrong.  I have a couple of similar motors so will check the linkage on those.  So it runs away but I could test it by working the throttle.

 

Niper99 – I took a compression reading before I tried starting the engine and it was about 115 so the leak a puzzle i.e. decent compression with a leak.  But that has happened to me with a leaking sparkplug.  I got 90psi but could not start the engine due to the plug threads leaking.  I don’t know how I could get 90 unless the rubber from the tester was enough to seal the leak. 

 

   The talcum powder test was false.  The muffler gasket broke and I did not have a replacement.  It was causing the talc to blow around.  What I thought was a line of talc removed from the head gasket seam was just talk that fell off in a line from the joint so misleading.  

 

   After a few short runs the engine tests at 115 psi.  With new rings and valve lapping I was expecting at least 130-150.  The cylinder was honed with a medium stone so possibly the psi might improve with wear.

 

   Because I thought the timing gear was wrong and going to unbutton the engine I drained the oil.  Up to that point the engine had not run and was only hand cranked many times.  The oil was loaded with very opaque gray color and the first oil to come out filled with fine suspended crud.  I’ll save that oil and tank it for later use as the first oil in another rebuild. 

 

   I’m a bit disappointed by the governor not working but that should be fixed with either getting the linkage right or opening the case again and getting the governor arm in the right position.  It sucks but minor.

 

   All in all I’m pretty happy that I made this much progress and learned quite a bit.  The next engine will go much smoother.  Thanks for all the help.  It’s really appreciated.

trouts

trouts2




Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1275

Re: Small engine repair questions, Tecumseh HSSK50
Reply #18   Jun 14, 2008 8:18 pm

  The glue I mentioned in other posts broke down so tiny spots of oil started showing up on the tires.  The epoxy turned to soft gum and let go so a few holes were exposed.  (The holes were from drilling into the hair line crack).  So muxh for the 3600lbs and 250 degrees rating.

 

   Since the holes and crack have to be cleaned and re-epoxy’ed  I drained the oil to unbutton the engine.  In the dregs of the oil was  what looked like a white tooth from the governor gear.  It makes sense as the governor was running away and very touchy to set.

 

    The drained oil is again very gray.  ??  Possibly something is wearing and it’s fine aluminum suspended in the oil.
friiy


Location: Las Vegas, The Desert
Joined: Apr 12, 2008
Points: 599

Re: Small engine repair questions, Tecumseh HSSK50
Reply #19   Jun 15, 2008 2:05 am
If it is metal it should settle out of the oil,  maybe put it into a glass jar and watch it...

it is not part of a ground up governor gear is it (plastic)?

You can always take it apart and check for chafing,  or wear in diffrent spots.

Could your piston pin clip have come aprt and beat a little metal off your piston or cyclinder?

?????

Friiy

trouts2




Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1275

Re: Small engine repair questions, Tecumseh HSSK50
Reply #20   Jun 15, 2008 10:10 am

  Opened up the engine. Three teeth were off the governor gear and intact at the bottom of the case.  There were also a few small chunks which were I think were epoxy which melted and fell off the case side.  They broke up pretty easily with a knife.

 

   The oil was changed after a few minutes of running and put in a glass jar.  It sat overnight.  That one had the small chunks, gray, and with microscopic pieces of metal which shine when put to a light. 

   The second batch of oil had about 10 minutes of run time and sat overnight in a jar.  It did not have any chunks but did have microscopic pieces of metal but fewer.  It was darker than the first batch. 

   It could be the small flecks are from the cylinder scoring.  I did not score it much but it was with a medium stone so it could be the flecks are from that.  It might also be that there’s some normal leaking past the rings due to the scoring making the oil gray. 

  

   The cylinder wall still had the scoring but looks like it’s wearing in.  The wall seems very smooth.  There’s no missing metal like chunks broken off the cylinder skirt so possibly the flecks are normal remnants of the scoring.

 

   When the engine was running it seemed overly noisy.  I had it mounted on a snowblower frame but pretty sure all the noise was from the motor.  I listened to it with long screwdriver and could not hear any grinding inside. 

 

    The governor gear assembly is about 10 dollars so cheap enough to give it another go.

trouts
trouts2




Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1275

Re: Small engine repair questions, Tecumseh HSSK50
Reply #21   Jun 19, 2008 6:11 pm
  Got the second motor finished and running today.  An older 7hp Tecumseh and it ran fine.

    The oil from this one was like the 5hp mentioned above.  After several minutes of run time I took out the oil and it was about the same as the oil from the 5hp.  The color must be normal and a result of scoring and blowby.   It definitely was not due to particles or crud left in the case as I steam cleaned the inside.

 

    Just looking at the dipstick there’s a slightly noticeable tint but seems clear with so little oil.  When all the oil is in a jar the oil is opaque.  I ran the oil through a few layers of cloth and only trapped a few minute specs of flashy stuff which must have been metal.  The grayish stuff that’s trapped is hardly noticeable other than it’s color in the cloth.

 

   It may be that the medium stones I used for scoring leaves the wall surface too rough. Next time I’ll score less and with fine stones.  One of the guys at the local dealer said I could skip scoring on an aluminum block but not case iron.  He said the aluminum was soft enough that particles of stone get imbedded into the wall.  ??

   Thanks again for all the help.  It was appreciated.

trouts

borat


Joined: Nov 10, 2007
Points: 2692

Re: Small engine repair questions, Tecumseh HSSK50
Reply #22   Jun 19, 2008 9:35 pm
If your oil has a greyish hue to it, that is normally an indicator or moisture (water) in the oil.   The best solution for this is to flush your crank case.  Some people use diesel fuel or kerosene to do this.  It seems to aid in getting water out of the tight spots. 

Not sure what you're trying to glue but anything on an engine's metal parts is best repaired with JB Weld.  This stuff is close to miraculous.   If you don't have any, get some.  It's simply amazing.  

I read an account of a guy on a dirt bike riding out in the desert when he punched a small hole in his crank case.  As a result, he lost all of his engine oil.  Being twenty miles from his vehicle and not having enough water to get himself out alive on foot, he set out to repair his crank case with some JB Weld Quick that he luckily had with him.   He repaired the hole and while the JB Weld Quick was curing, he drained the oil out of his fork.  He poured it into his engine and cautiously rode back to his vehicle.  With no oil in the fork,  and the engine with barely enough oil to keep it running, It was a  slow and rough ride.  Now that dude deserves the "McGyver of the year" award.        

trouts2




Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1275

Re: Small engine repair questions, Tecumseh HSSK50
Reply #23   Jun 23, 2008 8:16 pm
Borat,

    I had used PC-7 on the second attempt to plug the holes before you posed your comments.  The local dealer said it would hold through the high temps and should be strong enough.  Actually given the holes I think strength won't be an issue but ability to stand hot oil important.  The dried epoxy does not see all that strong so I'll probably get another shot at filling the holes.

   The governor gear which was stripped came in.  On looking at removing the assembly I'm a little puzzled about getting it out.  The gear assembly seems to just sit on a post - the governor shaft.  There's a metal coller stopping the gear from riding up so it will not slip off.  I looked under the assmebly with a mirror and there's nothing to unbutton so it seems like a press fit.  The governor assembly must slip onto the governor shaft with the coller on top of the gear.  The shaft seems like it would then be inserted into the gear case.  Is that right it's just a press fit?  I tried to move the pin with pliars with a cloth wrapped around the governor shaft but could not get the shaft to move.  The pliars even dug into the shaft.  How do you get the governor shaft removed?   Since I think the collar does not come off it seems the shaft must pull out but if not and I use a lot of force I might crack the case.  ??

trouts

trouts2




Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1275

Re: Small engine repair questions, Tecumseh HSSK50
Reply #24   Aug 10, 2008 5:01 pm

Followup on the rebuilds.

   The 5hp with the cracked block is finished and running very well.  Currently there is PC-7 in the cracked area with about 20 minutes of run time with the glue holding under heat so far so good on that part.  The motor is running very smoothly.  This motor had broken governor which I missed during the initial buttoning up.  The rod or a piece of the rod hit the flyweight and teeth on the governor assemble breaking the plastic governor gear.  There were long delays getting the assembly off it's post and getting a new one.   So the 5hp is running very well and the glue holding so far.  If it fails I'll take it apart again, clean everything and re-glue with I think it's JB-Weld.  The big deal for me is the rebuild part went very well.

  During the delay a 7hp Toro that was pushing oil was rebuilt and that one went very well.  It got rings and a valve job.  All the internal tolerances were to spec with the Tecumseh L-Head manual except the cylinder bore which I can't measure. 

   Also finished after delays was a Tecumseh 8hp which got rings, rod and a valve job.  The governor arm was not moving and controlling high speed so I took it apart and inspected everything.   Everything was ok in there and on putting it back together the governor responded properly so a mystery.  I don’t see how that was possible because there’s no room in there for the governor gear to be anyplace but in it’s proper place and weight able to move.  ??  Anyway I put the cover back with just a slit of an open space and a flashlight shining in to verify the govern gear meshed properly and then buttoned it up. 

   This all has been a great experience for me and very enjoyable.  I’ve had a lot of questions on this thread and a couple of others with related questions and appreciate the all the helpful advice.  When I started out I never had a concept of rings (plural) and the function of the distinct ring types.  By the way, Friiy, I never got a paper with the ring sets until the third set of rings cam in which explained the ring types and groves which by that time I was aware of.  If that paper came with the first set it would have solved a lot of questions I had. 

   The rebuilding was enjoyable, done in the cellar on my spare time watching TV and will give a few snowblowers an extension on life.  I’ve got two more motors with problems and will be doing those in the cellar during the Olympics.   As a note Harbor Freight opened an outlet close by and offering a 6.5 hp OHV engine with a cast iron bore for $129.  These motors have fantastic reports  on the net and an alternative to rebuilding. 

Thanks for the help:

Trouts2

friiy


Location: Las Vegas, The Desert
Joined: Apr 12, 2008
Points: 599

Re: Small engine repair questions, Tecumseh HSSK50
Reply #25   Aug 13, 2008 11:07 am
Sounds like a lot of good news.  Before you buy one of the Harbour Freight engines make sure you can get parts for it...

Now Harbour Freight  also sells some models of Briggs and also Robins. (both good).   But the Chen  Wen, or what ever is...  IS from what I hear impossible to get parts for..  the Robin is hard to get parts for..   It looks like Honda, part for part but is made cheaply in China and they rattle apart over time.

Good Luck,

Friiy 

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