# YS624 performance



## bcjm (May 29, 2015)

How well does your YS624 perform? I have mine for a few years. I am not impressed so far. It does not blow snow very far and clogged often if the snow is wet. The engine runs fine with proper RPM. I think the spec is 4000 rpm instead of 3400 rpm like other engines. The belt is tight. What else I need to check? I repainted chute last week. Maybe that will make a difference his winter. I never used other snowblowers before. Not sure this is normal.


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## leonz (Dec 12, 2014)

Hello bcjm,

This does not sound like a beautiful track drive yamaha for sure.

If the belt is too tight it may be the wrong belt also.

When was the last time you looked at the drive belt???

As old as that beautiful snow blower is it should be winning snowball fights with the local sasquatches!!!!!!!!!!!!!!!!!!!!!!!!!!!

I would look at the drive belt and if the rubber falls off in your hands it is time to get a new one.
If the V belt has cracks in the carcass it needs to be changed, if the V belt is glazed it needs to be changed.


You can get a new one from GPR Industrial

Part number 7Y64624200

$7.52 plus shipping and sales tax

1-800-391-6554

If you go to thier home page you can order it there too.

www.gprindustrial.com


You can always spray some Fluid Film in the impeller housing and the chute and double your casting distance too.


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## RC20 (Dec 4, 2019)

I think the spec for speed is 4200 max but would have to check. 3600 rpm is a generator speed (for what its worth). 

You didn't say how old your machine is, but as noted above, it should blow 25 feet easily. The only time it would normally bog down throwing is slushy snow and even that stops once you get it going.

It will throw 35-40 tons an hour if you worked it steady - the only machine I have seen surpass it is the newer Honda 724 (also tracked in our case). 

I ran a lot of snow blowers before we got the Yamaha back in 98 and it beat them all hollow including the Honda 24 inch at the time (5 hp as I recall, very low chute height to keep from overfeeding - that machine was truly under-powered and bad control setup) 

Our is still going strong, I only got the Honda because it had battery elecrtic start and the steering control stops back issues. In my opinion the finest snow blower until the HS724 with the modern features (I had little use for 110 volt starter, the battery makes it viable. 

Even the pull start is not bad at 3 max and one warm. Just more wear and tear on the back but I one arm it and counter that to a degree. I would love to have the electric starter at least to get it running. Different frams so you can't get one out of a wreck blower, no place to mount it.


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## bcjm (May 29, 2015)

I am not sure how old is the machine. My serial number is 832509. I am glad to get some confirmation that the machine is capable of throwing the snow well. I will go over and check everything again.


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## bcjm (May 29, 2015)




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## English_Cat (Sep 1, 2020)

Depending on how well run it is, the gap between the impeller and the housing could have something to say. It's an older machine, so it's not unheard of to have worn parts. After you do what the others have said, and if you are still not happy, you can do the 'impeller mod' to give it some throwing distance.


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## billy (Feb 11, 2011)

The older Yamaha's have known issues of twisted/bent impeller blades over time.

As English_Cat has mentioned above, take a look at your impeller blades to see if this may be the issue.


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## RC20 (Dec 4, 2019)

Agreed check all possibles but with that poor a performance, it has all the hallmarks of a belt of sheave issue and slipping. 

Ours was worked seriously hard to 20-21 years and it never lost a step in throwing. Honda throws further but my 10-20% not double or anything like that. The YS724 was listed at 46 feet, I found a solid 25-30 feet (and I did calcs and measured 40 tons an hour would be moved if you blew snow for an hour without no snow turns. 

PS: I just changed the Honda oil and put in Mobile 4T 10-40. I run it in my past cycles and current one as I start them regularly during the winter when we get a warmer spell but I did start it at 10 deg on time just to see.


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## orangputeh (Nov 24, 2016)

RC20 said:


> Agreed check all possibles but with that poor a performance, it has all the hallmarks of a belt of sheave issue and slipping.
> 
> Ours was worked seriously hard to 20-21 years and it never lost a step in throwing. Honda throws further but my 10-20% not double or anything like that. The YS724 was listed at 46 feet, I found a solid 25-30 feet (and I did calcs and measured 40 tons an hour would be moved if you blew snow for an hour without no snow turns.
> 
> PS: I just changed the Honda oil and put in Mobile 4T 10-40. I run it in my past cycles and current one as I start them regularly during the winter when we get a warmer spell but I did start it at 10 deg on time just to see.


I have never owned a Yammie but all I hear are good things.

Some Honda owners have the exact same problems.

I advise they check fast throttle rpms which on most Hondas is about 3600 ( check shop manual for your model )
Check auger belt adjustment and check for slippage/wear
Check impeller fans for being bent or damaged. I see a lot of impellers that are bent/.damaged.
check impeller bearing.
check inside of chute and bucket for scoring, pitting, damage.....anything that would cause snow to stick.
Use a non stick application on chute/bucket
Check gap between impeller fan/housing drum. anything other 1/4 inch or so ( if you have clogging/throwing issues ) I would install an impeller kit.

Usually well tuned / adjusted blowers won't need an impeller seal kit in most types of snow, especiallly high horse blowers. These generally work well with the real wet/slushy stuff.


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## JapDolls (4 mo ago)

Yamaha YS624T snowblowers from 1989 to 1994(?) have plastic fuel tanks and 4 forward & 2 reverse speeds. Do all the suggested checks mentioned in earlier posts with the impeller gaps & belts etc. I bought a 1989 YS624 new and its specs. for throwing distance was 45 feet (dry snow). After some 33 + yrs it can still throw snow from end of my driveway across a two lane country gravel road to/pass edge of vacant land on the other side, so about 40 + ft. at least. 
On the subject of belt condition. your belts when the tensioning pulleys are activated, the top of the belts should sit just about flush with the outer edges of the pulleys + - 1/16". Belts sitting lower down in the pulleys are signs of worn belts ( no matter how great a shape they may look esthetically ) and should be replaced because belt speeds are lost through belts going effectively around a smaller diameter pulley, hence lower impeller rotational speeds and shorter throwing distances. Good luck.


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## bcjm (May 29, 2015)

Thank you for the reference. I am debating if I need to do an impeller modification. What is your opinion on that?


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## Dan1023 (2 mo ago)

I have a a ys624t that i did a bit of restoration to. It runs amazing and throws snow far! Goes through the heavy end of driveway stuff without issue while my neighbors Ariens stalls out. I was going to sell it because i just bought a new Honda Hss928atd....but the Yamaha is just too awesome running to sell.


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## cpchriste (Jan 19, 2014)

In general yamahas dont need an impeller kit. If your impeller gaps have worn to 1/4" or more then maybe you could get some benefit from a kit.
Your easiest action when anticipating sticky snow would be to use a spray-on car wax on the auger and chute surfaces. One or two applications a season should be enough.
The next step up for sticky snow would be to install a chute liner of HDPE plastic sheet in the chute. Sheet is available in 1/16" thickness and is readily deformable with a heat gun. A 4" x 16" rectangle will be enough. Then pop rivet or use SS elevator bolts to secure it inside the chute. This will eliminate chute blockages and will also add throw distance.


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## bcjm (May 29, 2015)

I think the belt is stretched. The adjustment pulley is at the last hole. I ordered the belt from Amazon arrived today. It is too short. The https://www.amazon.com/PowerDrive-7...eywords=7y64624200+belt&qid=1669998241&sr=8-3
Not sure the Kelvar belt is different from the rubber belt.


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## tabora (Mar 1, 2017)

bcjm said:


> I think the belt is stretched.


Typically, belts don't stretch. V-belts wear on the sides and sink lower into the pulleys but the outside length remains the same.


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## RC20 (Dec 4, 2019)

You should be able to source the right belt from this outfit. I don't know which is the right part number for the blower drive. I have the spares and both come up. Its either 46241 of 46242 (TY6-46241-00 full for one). That said you should pull the belt and inspect it. Mine has seen 20 years of rugged service and has never been replaced because it looks like new still. 






Yamaha 7Y6-46242-00-00 - BELT | Partzilla.com


Buy Yamaha 7Y6-46242-00-00 - BELT. This OEM part is guaranteed by Yamaha's limited part warranty ✓ FREE Shipping on qualified orders - Partzilla.com




www.partzilla.com


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## cpchriste (Jan 19, 2014)

bcjm said:


> I think the belt is stretched. The adjustment pulley is at the last hole. I ordered the belt from Amazon arrived today. It is too short. The https://www.amazon.com/PowerDrive-7...eywords=7y64624200+belt&qid=1669998241&sr=8-3
> Not sure the Kelvar belt is different from the rubber belt.


I see they have the appropriate yamaha number shown there but that belt is 2" too small. You want a LB33 belt like this one www.amazon.com/PowerDrive-LB33-Kubota-Kevlar-Replacement/dp/B01N02U42N
If you can find a mitsuboshi orange or gold label in LB33 size, that would be even better (more flexible). Mitsuboshi was the OEM for Yamaha. There's one on the E of bay right now.


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## bcjm (May 29, 2015)

tabora said:


> Typically, belts don't stretch. V-belts wear on the sides and sink lower into the pulleys but the outside length remains the same.


I took the belt out it looks perfect. But the adjust hole is already at the last one and I feel it is still loose. I ordered another belt from the placed mentioned in the beginning of the the thread. Hopefully it will for properly.


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## bcjm (May 29, 2015)

I checked the belt I ordered for GPR. It also mentioned that it is 32”. Sigh.

*7Y64624200 YAMAHA YS624 Belt for Drive, W/32" Belt O.C.*


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## bcjm (May 29, 2015)

I just check the belt specs of LB33. It is 33” not 34”..


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## JapDolls (4 mo ago)

For your YS624, OEM Yamaha's specs for belts are LB33 for the auger and LA35 for the track drive. Note that the outside length ( for the LA35) must be a minimum of 35.5", otherwise it'll be too short even with the tensioning pulley at its minimum position and machine will creep forward when in gear without activating drive lever at handle. I had replaced mine with a AX34 cog belt ( 36" length x1/2" wide x 5/16 thick ) 2 yrs ago and it worked great. Like Tabora had mentioned in an earlier post, V belts wear on the sides only, so for condition of your belts even if they look "good", check their widths ( A belts = 1/2" ,B belts = 21/32" when new).


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## RC20 (Dec 4, 2019)

I have never looked at the Tensioning pully but it may be its at that hole because that was what worked not what it might be. 

What I have is LB-31 and an LA-35. Now that is a YS-624T and maybe there is a difference between a wheel and a tracked unit. That is from my spares and no I did not check the belts on it as the guys the sold them were super experts. I and they could be wrong but that is what I have.


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## JapDolls (4 mo ago)

Very possible that the pulley sizes for a wheeled and track units are different ( I can only speak for the track unit ). The LA35 belt for the auger is correct size for your machine. The LB31 ( outside length is 31+3 =34" ) for the drive is not OEM to the best of my knowledge. If machine had this set-up, then the original pulley(s) may have been switched out for smaller one(s) is my guess or Yamaha changed pulley sizes for later models to add another gear, like a 5th. If you still have the drive belt that was on the machine, measure the outside length with a string, then laid it out flat and measure with metal tape. Outside length of LB belts are 3" longer than what's on its label. LA belts you add 2". Good luck.


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## bcjm (May 29, 2015)

Got the belt from GPR industry today. TOO SHORT! Same length as the one from Amazon. This time I am going to order an LB33 belt. I can barely see the LB33 labeled on the original belt. I measure the OD of the original belt. It is 34.5”. The OD of the belts that are too short is 33”.


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## leonz (Dec 12, 2014)

Geesh!! Sorry to hear that your having troubles, hopefully they will take that V belt back and 
give you the correct cogged belt.


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## bcjm (May 29, 2015)

The first belt I tried to install even I felt it was too short. It got all dirty I don’t think I can returned it. The second belt I have to pay the shipping both ways it is not worth it.


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## JapDolls (4 mo ago)

If your new belt's( the LB33 ) outside measurement in length is 34.5" it'll definitely fit ( I have a spare for my YS624 track machine that measured exactly 34.5" ). My spare for the auger drive ( the LA35 ) outside measurement is 35.5" in length. I went with a cog belt AX34 for the auger drive because the old belt had developed a bunch of cracks from the narrow end of the V, an indication of the stresses belt undergoes when it stretches to ride over the tensioning pulley on its back and compresses to ride over the drive pulleys. Its my first cog belt, something new to try out, so jury is out whether manufacturer's claim of better life span will come true or not. Having said that, the regular V belts had given my machine some 10+ years of service before giving out, so no complains there.


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## bcjm (May 29, 2015)

My new belt arrived last night. It is labeled 5LK340 instead of LB33. I have not tried to install yet but I think it will fit. It is very close to the original LB33 belt.


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## tabora (Mar 1, 2017)

bcjm said:


> My new belt arrived last night. It is labeled 5LK340 instead of LB33. I have not tried to install yet but I think it will fit. It is very close to the original LB33 belt.


A 5LK340 is 5/8" x 34"
A LB33 is 5/8" x 37"


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## JapDolls (4 mo ago)

Hmm! 34" with the 5LK340 , you may luck out if you have more adjustment holes in the tensioning pulley bracket to accommodate shorter length, otherwise augers will rotate/creep even without lever on handle depressed for its operation.
BTW, your machine is a 4 forward & 2 reverse speed unit, hence 1989 and younger ( w/plastic fuel tanks ). 1988 and older models with 3 forward and 2 reverse speeds ( w /metal fuel tanks ) have slightly different pulley sizes hence also belt lengths i.e. LB31 for drive and LA34 for auger.


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## bcjm (May 29, 2015)

V belt has a different way to measure the length. It is not OD or ID. The 34”belt I got has an OD of 35.5”.


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## YammiRocks (11 mo ago)

Check this site out on how V belts are measured and labelled. V Belts | Vbelts4Less Top Quality and Service
If you have 35.5" outside length for the A size belt, it will work nicely for the track drive.


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## Cabincat (8 mo ago)

I may just replace belt in my YS624 (I have spare)…. It looked fine but perhaps it has more wear than I realize. Not overly impressed with throwing performance of this unit so far. Just dry power is like 20 feet… my Husky with a high speed impeller kit will do 40-50 feet. I do have a an unused 10 or so year old Clarence Impleller Kit I could install on this Yamaha. An option… I’ll take a measurement on the fan distance to housing. I suppose I need to line the chute as well.


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## Cabincat (8 mo ago)

Clarence Impeller kit made all the difference… throws the wettest & heaviest stuff a good distance now









YS624TE - I think an '89


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