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

Hello,

This is my first post here.

I recently got a used old Honda HS35 snowblower for $80.

It starts and runs with choke 'closed'. The choke knob is loose, moves around with the vibration.And when I put the choke on 'open' position it most of the time surges (up and down). I added some seafoam and noticed that it helped it stabilize on that day. I started it again today and it still surges when the choke is 'open' during the first few minutes, then stabilizes. Is this normal?  To start the machine the choke needs to be 'closed' or it won't start.

 This is my first snowblower, I have not worked on a snowblower before.

Auger's rubber parts are not new, the previous owner said he replaced them 3 years ago.It looks like rubber parts are worn by about half an inch maybe.Because I can see where the tip of the rubber was at one point by looking at the very thin end of the rubber.

Scraper bar is not rubber, it looks like it is made from harder plastic and the edges have 3-5 indents froms scraping. Do I have to replace these this year or will they work for now?

Is the price I paid fair for the machine I described above? Is it too much?

Thanks.

I can't help on price.  As for the augers. you might not be able to tell how good they are until you try it in some snow and see how well it works.

Most engines require full choke to start, then half choke for a couple minutes as it warms up then no choke after warmed up.  Every engine is different and the temperature also affects it.  You just have to get a feel for your equipment.

+1 on what Shryp said about the choke.   I think you got a good deal for that machine.  If there appears to be 1/2" wear on the augers I would buy new ones now and replace them rather than wait until we have snow to find out that they are too worn to work properly.  If they are badly worn the machine will not work very well and you may find yourself pushing it into the snow.  

Nice HS35 at a decent price.  Looks in pretty good shape considering it's probably 20 years old or more.  They sure don't make them as complicated as this model nowadays.  It's a very robust machine.  It still looks good compared to today's new machines.

I'd would get new rubber auger and scraper bar if they are worn out.  You can get them here .  Link.

Shryp wrote:

I think it is normal.I had not had a snow blower before or anything with a choke.After a few minutes with choke 'open' it runs fine after I 'close' it.

carlb wrote:

I downloaded the manual and it tells me to replace the rubber if the measurement from the shaft of the auger to the edge of the rubber is at 8.87cm. or shorter. It is 9-9.05cm. now if I measured correctly.

aa335 wrote:

Inside auger housing and on parts of the auger itself there is rust.I want to sand it and paint it next year if I can.

Thanks for the link, aa335, I checked that website and found out that the 'scraper bar kit' is obsolete.How do people replace it then?I called Honda Power America, they confirmed that that part (starting with 06...) is discontinued.However I saw this part and its MSRP on Honda Power's Canada website.Interesting.

Last night I asked my wife to come with me to look at another snow blower I saw online.150 miles roundtrip.I ended up paying $246 for this Honda HS621.A lot more than what I paid for HS35, hopefully it is worth it. What do you think? Its scraper bar might need replacement, but not sure if I should replace paddles yet.I did not understand how to measure the wear on this one or the manual was not clear.

Below I added a picture showing both.There you can see the rust on HS35's auger and its housing:

The HS35 is an old snowblower and Honda doesn't support this model anymore.  A lot of parts are obsolete, remaining available parts are quite expensive.  Check ebay from time to time.  You may get lucky and find the parts you need.

The other HS621 looks in good shape, almost no rust on the bucket or the fasteners.  Looks like this machine was not used very much.  You determine if the rubber paddles need replacement by measuring how much rubber is protruding from the metal edge on the auger itself.  If it is less than .6 inch, then it needs replacement.  Scraper bars are still easily available.  Make sure that the scraper bar still has enough material, otherwise, the pavement will grind away at the metal bucket.  Make sure you check and tighten all the nuts on the metal chute.  I've lost quite a few nuts falling off at inopportune times.  If you can, replace them with nyloc type nuts.  They have plastic inserts to prevent metal on metal loosening.

Visually, the HS621 still have enough rubber on the paddles to go through this winter.  It's a good machine.

aa335 wrote:

Thanks for the reply.

6 inch from where? When I look at the new part pictures the rubber's width does not look like it is not 6 inches even when brand new.

The manual says:

'Measure the distance from the outer edge of the auger (the metal parts paddles are bolted on or the housing?) to the outer edge of the rubber paddles.The paddles are worn out and should be replaced, if the distance is less than 15mm (0,6 inch).'

Did you mean 0,6 in? Or is it a different measurement?

The scraper bar, the hard plastic part of it has one broken part less than1/5 in in width and 2 in in length at the end of the scraper, not seperated from the main plastic yet.Is this hard plastic the material you mentioned?

Thanks again for your suggestions.

blumonster wrote:
0.6 inches from the metal auger edge.

Thanks.

bluemonster,

I had an issue with my choke as well because it was not connected.  Please take a look inside and make sure the Choke knob rod is connected to your carburator. I had to put some paint on the metal rod to make it thick and now the Choke knob does not move around and moves as directed so it works great. 

If  you don't have the choke working, it would be very hard to start.  I should be getting my OEM scrape bar and belt next Tue so I will can finish the project for now,  Your rubber pedals are no good and they are too worn out.  These rubber augers are real pain in the neck to install.

I do not know any efficient way to install them.  $36 is the best price I got including shipping.  These are not OEM as they are about twice as much. We will find out when we get some real snow.

Replacing those rubber auger in the HS621 is quite a chore too.  There are a lot of fasteners.  Make sure you inspect the condition of the fasteners, throw out the badly corroded one.  Also use anti-seize compound on the threads, lightly.

Do you think your Toro would be easier?  How's your father HS520 to change?  I think they are about the same.  The curves on the auger rubber make it very difficult to align them.   I am sure it is not time yet. It took a lot of brute force to get them off and install them.

MN_Runner wrote:
The Toro is easier for sure, there are a lot less fasteners, the rubber is soft, and they use hex on both sides.  Two box end wrench or socket on each side is all the two tools you need.  They use standard fasteners that can be found anywhere.

The HS520 would be similar to the HS35.  Don't tighten any fasteners until you get all of them in, this give you some flexibility and movement to align the holes. 

First curved rubber took me 45 min because of the learning curve then it was okay but still not that easy.  Having hard rubber makes it difficult when you have to curve it.

MN_Runner wrote:

I did that, thank you MN_Runner.I think the wire like rod was not fully on where it was supposed to be.I will do the paint trick also.Thank you.

Did you use two socket wrenches at once?Can I use a plier at one end (washer)?

All the bolts I can unscrew up to a point without the second wrench, then they do not move at all.I left it like that yesterday.Sprayed some more PB.

Manual suggests using soapy water to make it easier but I wonder if it would really work...Slippery...

Scraper bar was the easiest part, so you are done preparing the snow blower for the season then. :)

blumonster wrote:

I used 10 mm wrench and 10 mm socket wrench.  I used all combinations to get the grip within the given space.  All of my bolts came off easy.  The issue was slipping the rubber back in place.  I had to pry the spacings to make it fit.  In order to ease the slipping in process, I used armoral spray on the rubbers and metal to reduce the friction.  The scraper bar was not too bad, all four screws came off without a hitch.  The plastic liner points to the front and not to the back as shown in the owners manual.  My scraper and belts are coming in tomorrow so I will be able to complete the functional job.  I am going to buy some black marine paint then go over the rusts so I can work on the physical attributes.  I have sanded the rust spots off best I could but certain spots are beyond my interests.  My RPM is around 2700-2800 and the owners manual says 3600 RPM at the operating range.  What is your RPM?  What is the part number you got for your HS35 scraper?

MN_Runner wrote:

MN_Runner,

The plastic facing forward is the new design for HS35s starting with frame serial number 1048.... Mine is 1042...At some point the owner must have adopted the new design since the older design is obsolete, parts are discontinued.

Scraper part number is

11-75201-730-010 : BLADE, SCRAPER		SHIPPED		1	1	0	18.95	18.95
(Replacement part for 11-75201-730-000)

It is a part which was made in Japan.

Did you take the auger off to sand? Our garage is not heated, if I paint it probably won't dry and cure as it should.Maybe next year.

If your HS35's frame serial number is smaller than 1048... its ignition should be through 'breaker points' too.That is another design change according to the manual.

I do not know how to gauge RPM. How did you do it?

This HS35 has a backward facing scraper design:  http://www.youtube.com/watch?v=oce4k1ysl4Y&feature=related

I notice that it is in very good condition but I do not see the purpose of that wooden stick there.

Good! I ordered the same part as the one you have gotten.  I am planning to take the plastic cover off and start sanding it down and paint the metal. 

The hardest part will be masking the area that you don't want painted. My blower has a serial number of 1037823 so it is much older than what you have, but

the scraper housing looks same as yours and the rubber should fit just fine.  The previous owner must have changed it at some point.

I don't think he has serviced it in past 5-8 years. I have a tachometer installed on the blower so I can get direct RPM.  Not sure if it is worth the money ($20 shipped). 

I doubt HS35 will blow snow that good but I could be wrong.  I am not going to sink anymore on this blower after buying couple of $5 paint cans until I know this thing

can blow snow.

This is how mine sounds like:

http://www.youtube.com/watch?v=6Of_siqIYsk&hd=1

A nice machine, blumonster!  Your blower's exterior is in a much better shape. 

There was a small gas leak so it was fixed by tightening a couple of bolts that secure the carburator.

Unfortunately my parts are not here yet and are due on Monday.  The belt needs to replaced as it looks old and hard so I will do that on Monday.

At least, the belt job does not look too tough.

This is a complicated machine and it is amazing there really has not been that much major changes between 1980 and 2011.  If this thing blows

snow then I will be impressed as I have very low expectations.

blumonster wrote:
Very nice.  I like how these things look.  The top plastic cover looks like a hood of an automobile.  Sounds good too.

I don't know if the HS35 has a brake for the auger.  When you release the bail lever, the auger should stop right away.  There's a brake that rides over the belt next to the auger pulley that comes down when you let go the bail lever.  

No brake.  The auger spins until all the energy is dissipated due to drag and friction.

MN_Runner wrote:
Thanks.  Good to know.

Make sure you keep an eye on those fasteners, they like to vibrate loose.  Especially the ones on the handle and chute area.  I've replaced them with nyloc nuts when possible.

MN_Runner wrote:

Thanks MN_Runner, I have rust issues too.Next year if I have the opportunity hopefully I will 'recondition' it.

I saw moisture on fuel area too.Just above muffler.I might have the same problem.

I will add a picture of that area.

I got Gates brand equivalent Powerated V belts.I hear a squek-like sound when I first push the lever.I wonder...

Let's wait and see how they will perform.Hopefully exceed your expectations.

aa335 wrote:

I wonder the same thing too.I thought when I let the lever off it should have stop turning.It does not.

Maybe the belt is too tight, I have not opened belt cover yet.We will see...

blumonster wrote:

There are two 10mm bolts just above the exhaust.  I tightened these two bolts and now the leak is gone.  When I engage auger clutch, it does make squeak sound (this is with the old belt and will try it with new belt).  But cannot see anything really wrong.  My HS928 also makes squeak noise when I engage the auger too.  I just bought Krylon black spray paint and will give a try.  I am planning to cover the rubbers parts with the saren wrap (or clear plastic) then spray the paint over the area of interest.

Did your blower take almost an 1 qt oil to fill it up to the recommended level?  The sparkplugs are not easy to find either.

MN_Runner wrote:

Good luck with painting.I got a bad cold and could not get out of the house today.

It would probably take that much oil but I added approximately 0,7 qt.It is not easy to see oil level on the plastic dipstick. The oil I added was Castrol Syntec 0W-30.Maybe I should add till it drips from the mouth of oil area?The picture on the manual showed almost that high oil level, ready to drip even when the snow blower is level.

The previous owner mentioned using 30 weight oil on HS621, and the oil that came of that machine was thick.I do not know how he was able to start the machine in Wisconsin winters with straight 30 weight oil.

Around the screw on 2nd picture and around the bolt under the black hose on the first picture.

The condition of the old spark plug, the tip is whiter maybe because I added some seafoam.

I just have two more things (scrapper and belt) to do on my HS35 and am ready to blow the snow.  It would have been a perfect day for HS35 as we got a nice wet 4 inch here.  Here are photos on my HS35 after the $4.99 paint job:

MN_Runner wrote:

For 4 dollars the paint job looks great.

I read that the auger needs to stop when we release the auger engagement clutch.If not we need to adjust the clutch.I do not know how this will make it stop.

blumonster,

I think aa335 was right about having a brake to stop the auger.  When I saw the diagram of HS35 drive pulley

(see part #6 on http://www.boats.net/parts/search/Honda/Snow%20Blower/0/HS35%20A%20SNOW%20BLOWER%2C%20JPN%2C%20VIN%23%20HS35-1000001/DRIVE%20PULLEY/parts.html),

I realized that maybe the stopper is out of adjustment.  I will adjust this when I get the new belt tomorrow and make sure it stops when the clutch is released. 

BTW: You can order NGK sparkplugs via NAPA online and pick them up the local store.  Thanks for the diagram of the carburator.  It does not leak gas anymore but at some point I may need to replace all three gaskets. 

MN_Runner wrote:

Thank you for pointing out the stopper diagram, MN_Runner. I will have to look at it and adjust it if possible when I replace the belt.I have not yet.I have the belts.

I got the spark plugs from rockauto.I ordered 2 (one for the other Honda).It was around 5 dollars for 2 dollars everything included.NAPA tends to have higher prices for almost everything. :(

I added the diagram of carb area after borat's post/suggestion about following the carb linkage and governor.

Speaking of spark plugs, there are two different NGK spark plugs for HS35. One for HS35 with breaker points type ignition and one for C.D.I type. BPR4HS is for frame serial no. 1048.... and smaller, BPR4HS10 if I remember correctly for the newer HS35s with serial no. 1048.... and later.The spark plug gaps are different on these.NGK's part finder says the same thing...I had ordered the newer one from amazon but later found out that was the wrong one.

The stopper adjustment helps but I think my current belt is just too old and slippery.  The stopper helped on first few but after the old belt got warm, the stopper did not have much effect.

It is PITA to put the aftermarket paddles back.I could not put them on.It got dark and I left it for the day.

Maybe tomorrow.

The paddles look like they are not the same size.They must be, but they resist...

You will have to install the rubber when the ambient temperature is warm otherwise they either strink or harden making your job really PITA.  BTW: There is a guy selling a pair of brand new GX160 engine for $150 a piece.

I am attempted to buy one and replace it with the one on HS35 but this may be a losing proposition and not sure if GX160 has the same dimensions as G150.

MN_Runner wrote:

I will try when it is warmer.Thanks MN_Runner.

Brand new GX160? Wow! Are they made in Thailand or Japan? The string trimmer I returned had a GX35 engine from Thailand.

I have no idea about the comparative dimensions of these engines.But if the sizes are very close, everything else should be similar.Not a bad price for the engine.If it works then all HS35 will need will be wings. :)

It is made in Japan.  GX160 seems to have a higher height so it may not an easy fit.  It would be pretty stupid to spend more money on this HS35 but I have done many dumb stuff too.

MN_Runner wrote:

It is the best of you just wait for the snow and see how it works.I am sure it will be enough for the purpose you have in mind for the HS35.Just impatience. Snow will be here for a long time, so let's enjoy the last days without snow.Our neighbor was cutting their grass today.I did not do it.

Oops, you had snow already...

I wish you had a tachometer on your HS35 so I know what to expect on my HS35.  I am sure there are other HS35 owners here with tachometers on their blowers and wish they chime in. 

If the RPM is too low, the blower will not work too well provided that you have good auger rubbers and scrapper.  I specifically bought this blower for cleaning my pond and the deck.  I almost sunk my blower in the pond last year.

That would not have been really funny for me. 

MN_Runner wrote:

How do you connect the tachometer and where did you get it from, MN_Runner?  Is the RPM gauge reliable?Is it possible that it is not showing RPM lower than it really is?

Did you get the new spring?If it works in increasing the RPM to normal level I might get one as well.

Who else has Honda HS35?

Would not it be more dangerous if the snowblower is as heavy as HS35, on the pond?

HS35 is lighter than my HS928.  I almost sunk it last year when I went over the pond when the ice was not thick enough. 

I would buy tachometer from Norther Tools: http://www.northerntool.com/shop/tools/product_524744_524744?cm_mmc=Google-pla-_-Engines-_-Small%20Engine%20Accessories-_-160590&ci_sku=160590&ci_gpa=pla&ci_kw={keyword}

MN_Runner wrote:

How do you connect it to snow blower?

Is your tachometer like this?: http://www.amazon.com/Digital-Photo-Laser-Tachometer-Contact/dp/B001N4QY66/ref=sr_1_4?ie=UTF8&qid=1321906276&sr=8-4

If not, would something like this work?

I have never used this toy.  I think you have to tape someting (reflective part) on the rotating part and have the laser read it.  I am not too sure about the operation. 

You might be able to make an optical one work, somehow. But it would be a pain, I think. You'd need to get access to the crankshaft and put something reflective on it. Then leave that exposed (potentially dangerous, or likely not practical while also using the machine) any time you want to take a measurement.

The kind at the Northern Tool link are quite simple, you just wrap a wire around the spark plug wire, and it senses (via induction) when the spark plug fires. If the plug wire is exposed, you don't even have to install it permanently. Just wrap the tachometer wire around spark plug wire, and ground its other wire to the machine's frame.

RedOctobyr wrote:

Thanks for the explanation RedOctobyr.

Now I am the only one with a 30 year old snow blower.It was really a PITA to put some of the paddles.I damaged some parts around the collar.I gave a bath to the rubber in soapy hot water etc.Did not work.I have a couple of holes to match on bigger paddles and then the smaller ones.

blumonster,

You are a proud owner of 30 year old state-of-the-art snowblower.  I can vision myself sinking a ton of money on this machine so I quit before I lost more.  I thought about dropping GX160 but the height (base to shaft) was just too tall.

I have a concrete driveway, which is part of my development area code, so the rubbers would have wore out quickly and I have no desire to put those rubbers on again.  Look at the bright side, at least you have HS621 which is still being made today.

I have the early version HS35 (purchased 1982) snow blower that uses the discontinued 06761-730-000 Scraper kit or the 76215-730-000 "rubber shield", both of which are discontinued and very difficult if near impossible to find.  My rubber shield had cracked allowing snow to kick back (more or less at your feet).  Since the part is discontinued I decided to make my own part.  I ordered from a company named Zoro (www.zoro.com) product number G0805043.  This will get you a 3/16 inch thick piece of rubber (durometer 90 meaning hardness) that measures 6 x 36 inches for about $15.  My original piece measured 2-1/2 inches wide x 19-9/16 long.  You can get two pieces out of the replacement piece of rubber even if you do as I did and made the replacement 2-5/8 inch wide to allow for some wear.  Use a 3/8 drill to drill the needed (4) holes and make sure you insert the metal spacers into the holes.  They should be snug.

This worked like a charm.  Hopefully I can get a few more years old of the snow blower which runs beautifully in spite of it being 33 years old!

I guess it's a good thing that scraper is only a flat piece of rubber with holes.  Even though it is obsoleted, a duplicate one can be made easily.  If it was extruded or molded plastic, that would be a lot more difficult to duplicate the profile.

MN_Runner wrote:
Sorry to hijack this thread, but since there isn't much activity in this forum, I don't think anybody would get their panties twisted up.  :)

So I had a chance to replace the rubber paddles on both the HS520 and the Toro 421QE this winter.  So here's my assessment of what I experienced.

The Honda HS520 rubber paddles and plastic scraper replacement was fairly easy.  I bought the authentic Honda parts that included new shoulder bolts that matched up exactly with the holes on the rubber.  There was 19 fasteners to remove and install.  Everything was accessible with either a socket or box wrench  The rubber was fairly flexible and easily to align into the mounting holes on the auger.  Just take your time and make sure left paddles goes on the left side, right paddles on the right side.  An extra minute to organize the parts made the job goes smoothly  It took me about an hour to replace the paddles and scraper bar.  I had the machine in a heated basement so everything was warm and comfortable.  I would not have as much fun in a cold garage.

On the Toro 421QE, I decided to try the new Kage Polyurethane paddles.  These are the hefty commercial grade paddles and they look and feel tough.  It is very thick and stiffer than the stock paddles.  Here's the link if you want to find out more.  http://www.kageinnovation.com/en/snow-removal-products/rotor/  .  They are expensive, about 2x the price of Toro OEM paddles.  That's $39 a piece. 

I thought replacing the paddles on the Toro would be easier the Honda HS520, but that wasn't the case.  The single piece paddles means that I have to align all 6 fasteners into the holes.  That made it a little more difficult because the Toro bolts were slightly short when used with a thicker paddle.  Getting the threads to start was often difficult.  The paddles were stiff and didn't not bend as easily.  The 4 inner fasteners are relatively easy.  The two outer ones by the bucket sides were a pain.  I ended up taking the whole metal rotor assembly out of the bucket to install the auger.  That made the job 100% easier, even though it requires removing the drive belt, pulley, and bearing housing.  So if you get these thick Kage paddles. take the rotor off the snowblower and install the paddles.

So it took me about 1.5 hours to do the Toro with these Kage paddles.  if I had to do it again, it would taken me about 1 hour to do it I just remove the rotor in the first place. 

I haven't had snow to try out these new Kage paddles.  The fit is tight against the snowblower bucket.  I did run it dry and the extra heft of the paddles means that there will be more vibration and noise.  That is something to consider when upgrading to these.  But I suspect these paddles will attack the EOD piles more aggressively.  The tight fit means that it should be very effectively against slush.  I'll update when I have actual snow to test.

Thanks for posting this AA335. I will be taking my 221 in for service this offseason and after reading about these new auger paddles I was most definitely

going to request these. A liitle more noise and vibration won't bother me as it's already obnoxious to begin with! I look foward to your review after trying them

out in the snow. Thanks again.

ralphfr,

Just to clarify, these Kage polyurethane paddles for the Toro 221 / 421 / 721 models are aftermarket parts.  I highly doubt that your Toro dealers will have them or will install them.  That would compromise the warranty from Toro.

Toro does have the commercial grade thicker rubber paddles that goes on the 721RC.  Dealers are stocking these and are offering them as upgrades, if you so desire.

aa335 wrote:

Appreciate your clarification. I did assume these were the paddles that Toro was using on the 721 R-C. Did a little googling and found that the Toro parts manual for this model lists the part number as 125-1128 for the extended life paddles and they are about $40 each. The kit is part# 38205 and it cost about $90 which includes 2 paddles and the hardware. Cannot seem to find any info on what material Toro uses to manufacture these paddles. Definitely going for them. It would be nice if they fit as close to the housing as you say the Kage paddles are. If not then I might have to consider doing it myself and going with the Kage paddles next time around. Again great info. Thanks again.

If anyone else is interested here's the link to the Toro 721 R-C Parts Catalog: www.toro.com/en-us/professional-contractor/snow-removal/single-stage/Pages/Model.aspx?pid=power-clear-commercial-721r-c-38751

You're welcome.  I'm posting information about alternative replacement paddles  just in case people may interested in trying them out for themselves.  Replacing the paddles isn't hard, sometimes you just have to find the easier way to do it.  I do like doing these things myself as I get to know the machine better and appreciate the engineering thought that goes into it.  The more I know about the machine, the more I like to keep it in top shape.

I don't like the initial tight fit of the Kage paddles.  It's a little bit too tight.  It creates some drag and robs power from the engine.  I have sprayed Fluid Film on the bucket housing to minimize any wear to the blower housing during initial break in.  As the paddles wears in, the performance should improve.  Vibration and noise should improve as well.  Kinda like having high performance summer tires that need to be broken in after a few hundred miles.

The Toro dealers around here have a display of both Toro regular and extended life paddles.  From what I can see and feel, both are made of the same rubber compound and cords.  The only difference is the extended life version has about 1/8" more rubber.  Other than that, the number of fiber cords and the construction are exactly the same.  I don't see a huge difference, that's why I went with Kage version.

I don't think there will be a great performance gain.  I think Toro offers the extend life version to stay competitive with Ariens, which has a fairly thick and stiff auger.  The extended life paddles may potentially extend the life of the scraper bar.  Just a speculation on my part.  I do like Toro's implementation of the pivoting scraper bar.  The scraper bar is always in contact with the paddles as it wears down.  It works well and easy to replace.

My problem is I redid all the cement on my property a while ago and it has accelerated the wear on the paddles for sure. Considering that Toro's extended life paddles

are still made from the same materilas as the OEM paddles those Kage paddles seem like a bargain.  I'll definitely try the new Toro's and hopefully they'll provide

longer life. It also seems that the more the paddles wear the more blowback I get fron under the scaper bar. I just replaced it before this winter and it didn't seem

to make much difference. Hopefully I installed it correctly. It seemed pretty straightfoward. Again thanks for the information aa335.

I used the Kage paddles today on varying amount of snow, from 2 inch all the way up to 10 inches.  The throwing performance is no better or worse than the stock Toro paddles.  I did notice more vibrations and bumps especially on uneven pavement.  The polyurethane is definitely stiffer and does not absorb bumps as well as the rubber material.  There is noticeably less forward bite.  A couple of times, I lifted the handles to tip the machine forward and got snow blow back under the scraper bar.  Hopefully, this will improve as the paddles wear in more.