Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

I am contemplating installing my new adjustable carburator on my 10hp tecumseh engine....the red choke knob, how is it attached to the rod...threads? just pressed on?

Please let me know the secret of the tec engine.

bbwb

no such thing as stupid questions...some answers are out there sometimes.

but your choke knob just slides on.

later chris

Robert,

Since you'll have an adjustable carburetor, I think you'll find it interesting that you'll actually be able to simulate the surging effect at operating RPM.  The difference is that all you have to do is give the high speed jet a simple 1/8 turn open to richen the mixture, and it'll smooth right out.  When I look at my owners manual, they give so many reasons for the surging, but just can't seem to take the blame for the patches they use on carburetors in order to meet the EPA requirements. 

I've been using Briggs and similar engines since I was 7 years old.  Until about 1999, when I purchased a chipper/shredder, was the first time I experienced this annoying occurrence on a piece of OPE.  Hope your conversion works out.

Richie wrote:

Richie,

I don't understand what this surging is,  Are you describing the rpm running up above normal?  or just rpm fluctuating while the throttle position remains the same?  Just curious  thanks.

Mang wrote:

Hi there Mang,

That explains it richie,  thanks.

I would love to replace my carb, at 4400ft I'm losing some hp, and that dern oxy gas is crap, my blower stumbles every once in a while at any rpm and when I take it up from idle to full throttle even if i do it slow, it nearly dies, I think it's the gas.    Is there usually a place to buy non oxygenated gas(for ope) in cities that use it?

 Mang ,

  You lose about 2.77% of your HP for every 1000 feet above sea level.

You, at 4400 feet you lose about 12% of your engines actual HP.

                        Hope this helps!!

                                                    Fred   

Mang wrote:

Hi Mang,

At that altitude, you may have to purchase an altitude kit that consists of a different main jet.  If I'm not mistaken, and your machine is actually set up to operate at sea level, it may require a leaner high speed jet.  Less air mean less fuel is needed.  It may make the engine run better, but at some point, and I'm not sure if 4,400 ft above sea level qualifies, but the engine will never be able to achieve its optimum power output.  I suggest you consult with a local dealer for your machine.  They'll know exactly what you need.  Hope this helps.

jubol wrote:

Fred,

I just saw your post.  He's running too rich a mixture if he's set up for sea level, correct??

 Richie,

      Sure is!!!!!

That's why the adjustable carb is a great asset.

You can change your fuel settings on your carb any where you are in elevation.

                                                                Fred 

To rich huh, I guess that's logical, all these carbs are the same on this model no matter where you buy it probably.

Maybe that's why it stumbles?

 Mang,

      Please read the Richie "Got me hooked" thread on Carbs!!

  Might help you!

                                    Fred 

Mang wrote:

Mang,

It's just a simple main nozzle change that you need.  I don't have a nozzle size chart handy.  Unless I'm mistaken, all that has to be done is remove the bowl nut/main nozzle under the carburetor, and replace it with the appropriate high altitude version.  Funny thing is if you check your engine manual, you'll note that Tecumseh states that the sea-level carburetor configuration is good up to an altitude of 7,000 feet.   I don't know where these guys come up with this stuff.  My 50 HP twin cylinder snowmobile crapped out at about 2,000 feet above sea level requiring me to change the jetting while on a trip.  It ran very rich, spit and sputtered. Have your dealer get you configured correctly.  Let us know how it works out.

I'll take it to a dealer then,  for some reason I didn't think you could change the jet in these carbs,  I'll let you know how it works out.

Mang wrote:

Mang,

Sure you can.  It's just a fixed jetting rather than the older/better adjustable type.  Once the fixed jet (EPA version) is installed, the engine should start right up and run.  No further adjustment necessary.  The adjustable carburetor that I installed requires minor adjustments once started.  The difference is that I can dial in the fuel mixture for varied conditions and get the engine to run as smooth as possible. 

 Richie,

  The adjustable CARB should solve it all, If that is the way he wants to go !!

When you turn the screws you are either making it richer or leaner.

If he did that , that is, buy the adjustable carb, he might be better off as you are.

                                            Fred  IMHO  

I think I read some where on here that the oxygenated gas leans out the mixture a little,  So if I just leave it the way it  is, that might help compensate for the elevation change,  and I guess the colder it is the better it will run to,  more air

jubol wrote:

Hey there Fred,

I was actually suggesting that Mang change only the main nozzle bowl nut because that fix would only cost maybe $8.00.  I didn't want to recommend that he spends $55.00-$75.00 for an adjustable carburetor only to close up the mixture screw in order to lean it out.  I also assume this snowblower is used exclusively at altitude, if not, perhaps an adjustable carb may be a better bet.  In the end, an adjustable carb allows you to fine tune.  Fred, I'm sure either way should solve the problem.  I'm an adjustable carb man myself

Wow, this thread has taken a life of its own....

I am one of the fortunate ones who did not have that many issues with the EPA carb.  My blower always started right up and ran well without surging or acceleration problems.  What got me going on the adjustable carb was the post by Richie (Yes, Richie you did this to me) who stated that the new carb allowed the engine to run alot smoother.  My engine always vibrated what I thought was too much...it actually caused the blower to move on its own from the vibs.  The new carb, now adjusted properly has smoothed out the beast quite a bit.  I think that I now have some more power but I always seemed to have enough.  This last weekend I used my neighbors 10hp Ariens that is about 8yrs old.  His engine sure runs alot smoother and always did compared to mine.  His blower has an adjustable carb.  I noticed that his machine did not seem to have the same amount of umph that mine does.  I believe that his machine could use some adjustments the governor and the carb, but I am not going to mess with them, with my luck, something would break and I would have to get it fixed.

bbwb

bbwb wrote:

Robert,

I am just one of those guys who figures if it does not run perfect, there must be a better way to make it do it..  It does not take to much to plant a seed in my head to get it to grow.

I will admit that my neighbors machine has a much, much better drive train than mine has.  His will outlast mine by decades.

bbwb

sorry to highjack your thread.   I agree all this talk about things that can be done, I also want my machine to run as close to perfect as possible.

Mang and Richie:

No appologies needed...I don't mind having additional thoughts added to the conversation.....at least I know people are reading the post

bbwb

Mang wrote:

Hi Mang,

Once you pass 3,000ft elevation, you may also want to consider tossing out the standard heat range spark plug and going with a hotter one.  One range hotter, perhaps two.  Once you do that, check the plug regularly to confirm it's burning the correct color.  As for the spark plug gap, going with .028 rather than .030 the owners manual recommends is preferred, and it what I gap my plug at.  It is possible to regain a small portion of the HP loss you are experiencing due to your altitude, but that would require advancing the timing several degrees on the engine.  I'd see your dealer about making that modification to your flywheel.