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

Picked up a beatup YS624W which needed work.  It came with a matted mouse nest in the tractor base and a worn through impeller barrel due to tossing rocks.  The rusted sections on the right and left of the barrel bottom are pushed out about 1/2 -3/4 of an inch.  The main drive gear support post and flange bearings were also worn (pictures below).

The impeller area diameter is only 10.5 inches and has a whole worn through.  The worn an pushed out sections are in the forward part of the lower barrel.  A sheet of steel was installed with rivets.  The machine is an impressive tosser and due to it's high impeller speed and powerful engine that does not sag much under load so able to keep up the RPMs.

A nice feature is a class viewing window to check the oil level.  Note the heavy cast iron oil catch whch is part of the bracket for the engine support mount.

The impeller arms are mishapen and the plate also distorted but not as bad as the picture shows.  The bent area is due to camera angle distortion.  Note that the impeller diameter is 10 inches.

Got the impeller back into reasonable shape and put on some Rustoleum.

The muffler was rusted but the metal solid so taken off, wire brushed and painted with hight temp paint. 

Muffler heat shield and air box covers painted.  Muffler in much better shape.

The engine sits on motor mounts about 1/2 in above the tractor base.  Two big rubber mounts on standoffs support the mounts which are connected to the engine cover by heavy brackets.  The left facing bracket has a rusted section at the L bend.  It's cracked at the rust area for almost it's entire lengts.  I've had about 6 of these machines and two have had broken motor mount brackets.  The other was on an 828 base bracket but both 6 and 8 hp machine use the same bracket.  2 out of 6 with broken brackets makes me suspect that the brackets may be a weak point in the design.  I did not notice on the other machine if the brackets were broken or cracked but they may have been. 

Note the brackets are mounted to the engine front cover which is made of very thick aluminum about twice the thickness of a Tecumseh cover.  It's also very nicely machined. 

Rear engine mounts.

The engine is raised up off the base about 3/4 of an inch, enough to snake a cable underneath.

Wheel drive gears are enclosed in a case which mounts to the tractor base side.  Note the grease is well spread on the gears.  There are voids in the case but the paste grease still got around somehow.  BUT, notice the center of the primary gear on the left.  It's mounted on a post with flange bearings on both sides.  The flange bearings were completely worn away.  There were no traces of the flange bearings in the case.  They had been ground to a powder and mixed into the grease. 

The gearcase cleaned up.  Note the roller bearings in the case.  You can see the primary gear support post is heavily worn out of shape.  The post is a tight fit so pops out and only a few dollar part.  The post may be a weak point in the design due to not getting any grease.  The flange bearings on the primary are very thin and do not have self contained oil so they don't get lub'ed.  The gase does have a gasket so fitting a new gasket and adding sealer might be tried in hopes it will hold liquid grease.  A screw hold can be added to the top for dumping in liquid grease.  The primary gear center section was worn so bad it had to be replaced, $89.  The teeth of both gears were fine so the paste grease fine there but did not help much for the center section and post.  All in all it lasted about 26 years so not bad but having lub would be better.

Nice engine with lots of power.  Note no crankshaft going out of the block.  The drive is from the camshaft PTO.  The engine runs at 4000 rpmon the 6hp and 3850-3900 on the 8hp.  The PTO runs at 2000 RPM.  The rakes I think run at 300 and the impeller 1400 or so.  These engines are very nice and do not sag much under load compared to a Tecumseh.  They are at least equal to a Honda GX and probably better.  Note the black rubber mounts on top to dampen gas tank vibration.  The tank has 4 posts and set into the tank mounts with hair pins.

Nicely machined head area.  The engine is getting rings and a valve job.  The engine compression was within spec but at the low end of its range but it had very good spring back.  It would be nice to get it peaked so with get some work.  The goal is to get it running well and compare it to a Honda 624.  The Honda 624 is a great machine and so is the YS624 but I think the Yamaha may have a slight edge.

When the piston is covered with my hand and the flywheel turned through a compression stroke the flywheel will bounce back and the spring back can be done once or twice more before it leaks by the rings. 

Liner inserted and painted. 

Lower bucket side distortion due to being thinned and pushed out by rocks.  The machine will clean up nicely but unfortunatly will have the rivets showing and the bulges.  

Good luck with your project. You have a lot of work . I hope it is worth it in the end. It looks like you fished it out of a dump. Let us know how it turns out

It's amazing that someone would abuse a machine as nice as that and let it get to that point. Great work salvaging that one trouts!

trouts,

if anyone can resurrect the dead snowblower, you are the best man for it.  look forward to seeing it this fall.  if you bring it back alive before the Easter, it would be a miracle.

It looks really nice.  What was your cholce for a color match?The wear in the gearcase is interesting.  Would a grease fitting on the gear case had helped to keep the center post and flange bearings lubricated?  For such a well designed machine lubrication in the gearbox seems to be the  achilles heel. This wear seems prevalent in both the 624 and 828.  Do you think the Yamaha's side valve design is a match for the overhead valve of the Honda 624?

I>>>What was your cholce for a color match?

Dupli-Color DE1601 Ford Blue but DE1621 may be a better match.  Rustoleum has one close. 

 

>>>The wear in the gearcase is interesting.

    I had a Honda with the same problem.  The gearbox in the pre-hydro machines used the same design gearbox side mounted to the tractor section.  They used needle bearings on the primary gear.  The needle bearings were pulverized so no trace of them.  The only part of the needle bearings left was its outer case.  The spread of the paste grease was the same as the pictures above with plenty of grease on most of the gears but little at the center.

 

>>> Would a grease fitting on the gear case had helped to keep the center post and flange bearings lubricated? 

    It might by loading so much in there it will work around like up the gear spokes and case side wall to the middle.  Liquid grease would be better would have to be sealed well.  In both cases the gears lasted 20+ years.  It might be the grease stiffened and could not flow and creep its way around as in the early years.  ??

 

>>Do you think the Yamaha's side valve design is a match for the overhead valve of the Honda 624?

   It may be.  I’ve used a few Yamaha 624’s in the past and this year used a Honda 624.   The Yamahas were very impressive.  This year I got a Honda 624 and was not impressed at first but after several storms it’s also been very impressive.  It’s tough to remember in detail the performance of the Yamaha but I think it would match or beat the Honda.  Both engines are fantastic.  I don’t see complaints about either engine.  The GX series is well established.  I don’t see complaints about the Yamaha snow engines and there are plenty of 20+ year machines around with good engines.  The engine on mine was within spec.  The ring and valve work just an attempt to peak it.   You had an over spec reading on yours and I’m interested to see what the rings will do on mine.  I’m hoping for high 70’s or 80’s. 

Thanks for the analysis & "intimate" view of this machine. Nice to see  that some one else can see past the ugly duckling and realize there is still some swan left in the old girl.
Just wondering if that larger car style muffler helps contribute to the reduced noise of these machines?

Keep us posted on the engine teardown.  I would be curious to see what you find.  Will you need to replace gaskets for the head or can you re-used the one that came off?  I have always wondered if there was an easy way to remove the oxidation on the aluminum block to make it shine up.  On smaller (more accessible) parts I have used a soft bronze wire wheel and had acceptable results. But there must be some way to polish up the cooling fins. Maybe soda blast them? I've never tried that.

GtWtNorth>>>Just wondering if that larger car style muffler helps contribute to the reduced noise of these machines?

 

 

  It quieter than a Tecumseh.  It’s got a nice deep note that sounds potent.  BTW: the muffler is substantially built, heavy.

 

 

Underdog>>>Will you need to replace gaskets for the head or can you re-used the one that came off? 

    The rule of thumb is head gaskets should always be replaced.   A new gasket is on the way but I think the original could still be used.  The seems to be in perfect condition.  The mating cylinder and head surfaces are very smooth and clean and very much unlike what I’m used to seeing on Tecumsehs. 

 

 

>>>I have always wondered if there was an easy way to remove the oxidation on the aluminum block to make it shine up. 

 

 

   There are agents and processes but they are expensive and bothersome.  I don’t know of anything off the shelf that works.  I use any liquid and a wire brush.  The white stuff on carbs is a problem. 

 

 

>>>But there must be some way to polish up the cooling fins.

   Possibly Mothers but that’s a pretty bumpy surface and would probably look weird if you took the several hours to buff the fins out.  May be you could get it chrome plated at a hog shop. 

 

 

>>>Maybe soda blast them? I've never tried that.

   Soda blast?  I’ve never heard of that.  I’ll have to google it.

Anybody tried POR15 for this kinda stuf?  I found it amazing on rusty cars.  Does what all the other "rust paints" say they do, but dont.  There is even a heat resistant variety for things likee that muffler.

Search soda blast on youtube. If you have a compressor you can make a blaster pretty cheap for occasional use. Harbor Freight has a small one on sale for $99 right now. But aluminium oxidizes pretty quickly, it won't stay pretty for long.

>>>Anybody tried POR15 for this kinda stuf?  I found it amazing on rusty cars.  Does what all the other "rust paints" say they do, but dont.  There is even a heat resistant variety for things likee that muffler.

 

I’ve seen Por15 on a snowblower and it worked very well.  It’s expensive, requires steps and color limited but can take overcoating.  If you’ve had rust problems with the “rust paints” maybe you did not use them properly.  Rustoleum works fine.  How many of “all the other(s) have you used?  Which ones have you had problems with?

 

Bill_H,

    Never heard of soda blasting until Underdog mentioned it.  Thanks for mentioning the HF soda unit.  It caused me to google around.  There are a few videos of the HF units which seemed to work well enough.  I’ll have to check them out at HF. 

POR15 is head and shoulders above the rest.  It does not just put a coating over the rust, it chemically combines with it and prevents all further rusting.  I did some work on a rusted Isuzu Trooper seven years ago and it still looks like the day I put it on. Previously I did try various rust paints like rustoleum and several others.  With and without rust converters and priming first.  All failed within a year. usually much less given the severe conditions it was exposed to.  The POR15 is very different to work with because of its properties.  But it goes on thin and really isn't much more cost than the rust paints.  Once you develop the technique it is really quite easy  .But dont plan on reusing your brushes  and do wear plastic gloves lol.  The only real drawback is that its only available in black or grey.  If you want colours it does get pricey because you have to buy a special primer and overcoat to do it (although their advisor told me that you can very lightly overspray it with eneamel just before it sets and then apply a thicker enamel coat later, and this did work fairly well for me).  They also sell a heat  resistant paint that is quite good - put it on a high temp engine component also and its still there.  They also sell a POR15 paste in tubes that you can use to build up rusted areas - I tried this also on the trooper - takes quite a bit of prep work and is messy, but if you do it right it lasts as good as steel - and it has a tensile strenghth almost as high as steel too.

Would be ideal for the impeller, augers, and inside of the auger housing on a snowblower because these areas are exposed to sand and gravel erosion.

This stuff is really tough - I used to drive 70 miles/day on gravel which "sanded" the frame of the Trooper and exposecd it down to bare (and rusted) metal in just a few weeks.  The POR15, properly appled, is still there.

Woffie:  “Previously I did try various rust paints like rustoleum and several others.  With and without rust converters and priming first.  All failed within a year.”

Hard to believe.  In fact I don’t believe  it, sorry.

No one drives their snowbower down a gravel dirt road for 70 miles.

Por comes is 5 colors and can be overprinted with any paint >>per Por.   Call Por instead of fanaticizing facts.

Believe what you like troutie,  but I've been painting with rust paints for 30 years and for 7 years with POR15 and I know what works and what does not work.  And...read the post again - it was not my snowblower I was referring to, it was my Isuzu Trooper.  And people do use their bowers on gravel and EOD stuff full of sand, gravel and salt.

Doggie boy and/or whatever other names you use >>>"it was not my snowblower I was referring to, it was my Isuzu Trooper."

No s...!

Maybe the above is the issue with your rust product use failures.   You can't read.

wolfee,

are you using that rust protection on your Honda snowblower?  show us some pictures of the rust protection on your beloved honda?

I did a lot of research on rust treatments over the years and tried several. My experience (I admit somewhat limited in the # of products I have personally used) seems to match up with what I've read online. POR-15 works. **IF** you properly remove the rust down to solid metal. But so do a lot of less costly treatments. Nothing works if you don't remove the old rust. I've had very good luck with the phosphorous based rust treatment products, both NAPA brand and Rustoleum seem to be the same. Clean the metal, removing all old rust. Brush/spray it on, let it dry. Hit it with a green Scotchbrite pad. Apply a good primer, then a good paint, you'll be at least as good as the factory finish. I've never had anything work for more than a year or two if I didn't clean off ALL the old rust first.

Well, I guess you can lead a horse to water, but you can't make him drink.

Bill_H>>> I've had very good luck with the phosphorous based rust treatment products,

   Same here.

 

Bill_H>>>Nothing works if you don't remove the old rust.

Yes, I’m mostly in agreement with all you said. There is embedded rust and minute pocked areas that full removal will leave a very distorted surface.  It’s too much to deal with for OPE.  There are also areas that are too cramped to get into to sand, grind or even wire brush well.  For OPE it’s impractical to get it all and patch or replace like you would on a car.  For embedded and other tough areas I found multiple treatments with rust products and brushing to be effective.  The cleaned/neutralized areas are then primed and painted with rust products. 

I’ve tracked a few snowblowers I’ve done and sold  The oldest is in it’s forth season.  The bucket inside was very bad.  It was sanded and wire brushed.  The surface was rust pocked so impossible to get at all the rust.  The inside was given repeated treatments of Must for Rust which is nothing special and like the rest.  The inside was given a few prime coats then coats of paint, both Rustoleum.  So far the paint has held up.

What I have found is rust products will not act on rust the same way all the time.  The metal used by various manufacturers is not the same and the character of the rust is also different. 

 

NASA has found Navel Jell to be useful and used it on its supersonic wind tunnel. The reason for the choice was similar to what the average person would use.  Navel Jell worked, it was cheap and easy to use.  The other products that did a better job were eliminated for cost and difficulty of use.  For OPE it’s a great treatment for up to 6 months because of it’s protective coating or the coating can be removed for painting.  They also used Rust Converter.

 

A decent rust info link is:

 http://www.metalwebnews.com/howto/rust/rust.html.  <<For the catatonic, the link must be cut and pasted.

Bill_H,

   I tried a soda blaster lashup with the compressor, airgun nozzle, tube and box of cooking baking soda.  It cleaned up an engine a bit and did remove some light rust.  No bad given the setup.  It was very messy though.   With the right soda and a better setup like the low end HF units it would probably be useful.

   The parts came is so work progressing on the 6hp rebuild.  Both the cam and the crank are on nice roller bearings.

  

Nice supports inside.  The crank cover has a lot of meat and much heavier than a Tecumseh cover.

Tecumseh 7hp on the left, 6hp Yamaha on the right.  The lobes are about the same size as a Tecumseh but the gear much bigger.

The internal supports are at least twice as thick as a Tecumseh and the finish much smoother.

Pistons are the same diameter.  Again much niger finish on the parts.

The bore is pretty smooth.  Note the wear is not front to back across from the skirts as is usually found.  The scuffing is on the side probably due to the cam being the driver.

The poston moves in bore very easily compared to any other Tecumseh I've worked on.  That may be due to the rollerbearings and better maching (I've never worked on a Tecumseh with roller bearings.  Postons are usually hard to get out of the bore.  It usually requires using a soft pine stick to push the piston out of the top of the bore.  The Yamaha piston came out easily with pusing up with my hand.  The difference was interesting.  The engine had an oil change before disassembly and filled with synthetic.  I'm not sure if that made the difference or better machining.  The bore still has lots of cross hatching so I think I'll do the cross hatching for the new rings by hand with very fine grit paper. 

   One other interesting thing was it was after the rod was taken out the bottom part of the rod was very difficult to get off.  It was held on by fit and the suction of the oil.  Tecumseh lower rods sections always just fall when the screws are loosened.   Big difference and probably due to better metal and machining.

These are great images.  Much better than looking at the Yamaha parts diagram.  What did the valves look like? Will you be replacing the rings and if so will you go up a size?

Looking good Trouts,

What kind of metal did you use for the patch?

Did you "wet seal" the patch in to keep water from accumulating between the patch and skin?

Friiy

Underdog>>>What did the valves look like?  Will you be replacing the rings and if so will you go up a size?

 

   The valves were good on the leakdown test.  The seats and faces were good also.  The lapping was a touchup lapping. 

The rings were replaced with standard rings.  All the internal measurements were within spec.  The engine was an ok engine and within spec but the compression reading on the low end of the range. 

When apart I put my palm over the bore and worked the flywheel to judge springback, that would be in the reverse direction testing for suction loss by the rings, the springback was pretty good.  I could work the flywheel a few times before loosing suction.  With the new rings it would spring back 4-6 times. 

With the old rings the compression was 58psi and within range.  With the new rings and about 30 minutes of breakin it’s 80psi.   The engine got an oil change at about 3 minutes or run time and another at 10 minutes.   Fairly cheap 15-40 used for breakin.  The engine has about 30 minutes of runtime and will get an oil change today which from here out will be synthetic.

By the way, the local Honda dealer has a device for converting the LA LB type of designations to the standard belt size designation. 

 

 

Friiy>>>What kind of metal did you use for the patch?

   A sheet of 1/8 steel riveted in.  Not the best but I’m not setup for metalworking. 

 

>>>Did you "wet seal" the patch in to keep water from accumulating between the patch and skin?

No, I used up all of that good glue you sent up on the Honda fixup.  I’ll have to live with the voids and go with the drain hole at the bottom.  The fit was pretty good as the metal in the barrel area was still mostly there and no out of place or round like the Honda repair.  I was going to get extensions welded on the impeller arms but the fit was close enough to the barrel that I dropped that.

 

The engine is done and mounted on the tractor.  Yesterday the new drive gear and bearings went in and the rest of the tractor parts installed.   There’s just the bucket to go back on maybe today.

Trouts, interesting seeing the Tecumseh and Yamaha side by side.    I believe I read that the Yamaha is around 25 years old but what is the approx age of the Tec?

35 worthy and honorable years. 

My brother runs a few 6hp's that are 45 years old.

80 psi on the compression.  That motor is going to run for another 30 yrs.

How has the engine been to start? Many pulls? After it starts is it finicky until warmed up or does it settle right down?

Labor aside, how much should I set aside for a ring set and gaskets?  

That belt conversion has me interested. I just cringe at the thought of spend $40 for a V-belt.  

Underdog,

It sounds very nice, aggressive with a deep note.  At 4000 it’s ferocious and seems like it could go through any amount of EOD easily.

 

   Starts on the second pull and can go to full throttle quickly without barfing.  It can go quickly to low idle also.  No finicky warm-up on this one.  The second pull start might be a sluggish fuel pump.  If it got a wicked rip for a first pull it might start.  I definitely lucked out with this engine.

 

   The rings are $13 and the head gasket $8 from boats.net.  It did not get a piston (84) or a rod (64).   Pricy but quality.   Parts are reasonably priced at boats and just about everything is available for these.  Worse case they have to go to Japan for parts.  Some things marked obsolete but are available on other models which is weird like the auger support bearings.  They used a standard size 6203 RS (RS being sealed).  Honda also uses 6203 but a LU and UU which I think are more ruggedized for slow turning.  The bearings in the older Yamahas are often shot but the same with older Hondas.  I found a non-OEM 6203 RS for $3.50 in 10 packs which I might get.

 

>>>I just cringe at the thought of spend $40 for a V-belt.  
   They are wicked nice belts but a HD Kevlar should be fine.  The expensive drive belt on this one was replaced within the last few years and in fine shape.  The drive belt has some age but also in good shape.  

 

    Doing the rings is fairly straight forward like a Tecumseh.  The only caution is to set the governor weights in place before installing the cam, easy.  The hard part is getting the engine off and remembering how to put it put it back on in order.  It was done in 4 steps with 4 parts piles to help me remember how it goes together.

Those parts prices are really not bad. Some of the YS624 came equiped with electric start.  It there an advantage to the metal tank vs. the plastic tank? Or visa versa? We are all still waiting to see a photo of the blower back together again!

   The electric start versions are nice.  I had a YS624TEN and sold it.  I'll probaly never see another.

   I've never had a metal tank model.  They are the older versions.  I've gotten used to and like the plastic tank because it won't rot.  It's does vibrate a lot though even with the rubber mounts.  I'm not sure about the metal tank but I would think it bracket mounted with no rubber gromets. 

   The project is done except for buttoning it up.  The shear pin was rust frozen in and had to be drilled out.  Broke several drills and two punches.  I then found the auger rust frozen to the axle.  I've given it a couple of applications of heat, twisting with a big pipe wrench and lots of PB Blaster but it won't budge.  I only have MAP gas.  I'll give it a few more tries and if it does not break bring it to a shop.  He's got gas and a 20 ton press.  I would not mind buying a press but I think you have to have gas with a press.  When I get stuck and bring things to the dealer he always has to use both to get things to break. 

    Finished the Yamaha.  The machine cost $70 and the parts $210.  For $280 the machine is an OK deal.  It's working fine and will make a great machine.  The work in was reringing, valve job, back auger support bearing, auger bearings, carb rebuild, main drive gear, bucket liner, decarbonize the head, reset the impeller, unfreeze the augers and wheels, paint and assemble.

The brown is some protection for the engine supports which rust in those areas.

It's a got a $#%*fortable to use dash with a nice chute control, remote hood, on off switch on the right and a useful range of gears.  I've never used a Yamaha wheeled before but the tracks are great.  The reverse on these is fast enough to make backing up a non-issue.  They controls have rods which can't be seen and the cables used are very good quality.

The shifting components are complex and tough to set but once set the operation is smooth and easy.  The shift internals in the tractor section (can't be seen in the top picture) and robust and even with the abuse this machine had all are shiney and look new.

Looks good! Going to keep it for yourself? Seems like there should be plenty of years left in it.

Bill_H wrote:

    If there's anything in there that will wear out in a few years I missed it.  

    It will probably stick around until we get a few decent storms next year and I get some use on it.   I've got a Honda 624 track I want to test the Yamaha against. 

NICE JOB TROUTS!!!! Looking real good.

The routing of the chute control says it all.  Yamaha made every effort to create a machine that is a joy to use (and worth rebuilding).   Speaking of "using" are you sure there isn't a pile of snow left from this past winter?  Maybe behind a garage wall or near a hedgeline?  With all that snow we had last year there must be something to blow. 

Note: if you removed the bolts that hold the friction pads at the base of the chute be sure to locktite them back in place. Vibration can easily cause them to shake loose and drop off.  I lost one of those when I was working on the blower last year. I keep thinking that parts will turn up now that the snow is gone.

u could go to a hockey areana they'll have some snow out back to plow LOL