Jump to content
Sledguy74

2021 Yamaha’s

Recommended Posts

1 hour ago, Motorhead said:

The chain case on them is a weak point.  Poor engineering. Friends srx failed at 4000miles. Previous viper also let go as well. 

Does not trust his machine . Maybe if you baby it they will last. They look pretty on a tow rope though.

Typically artic cat design like diamond drive? How did your replacement 850 engine work out this winter? Going to a four stroke or sticking with 850? I miss 600 etec, maybe try 600R next winter or a poo

Share this post


Link to post
Share on other sites

Holding up good so far. Put over 3000km on the used engine. Should be good to the 20k mark now. It's a bit of a Frankenstein sled considering the tunnel was replaced as well when the track blew off last March.  Wish they had just wrote it off but they repaired it. All in all its still a great sled. I am going to keep it as the value on it now is garbage. I have a 2016 1200 as a back up anyway. Took that for my week run in Quebec.  Matter of fact it was on the same trip this year my motor blew that the next day his chaincase let go. We always maintain stuff and let things warm up and such but crap still happens

Edited by Motorhead

Share this post


Link to post
Share on other sites
15 hours ago, Motorhead said:

The chain case on them is a weak point.  Poor engineering. Friends srx failed at 4000miles. Previous viper also let go as well. 

Does not trust his machine . Maybe if you baby it they will last. They look pretty on a tow rope though.

The biggest problem is the two flat head screws holding the axle for the chain tensioner wheel come loose and the the axle spins and the screws fall out.  The wheel then falls to the bottom of the case where the bottom gear blows the tensioner wheel through the case and breaks both halves.

 

The case does not magically break from the immense hp going through it.  The permanent fix is to TIG weld the screw heads to the tensioner bracket so they cannot come loose.

 

Problem two is the teflon coated oilite bushing in the top sprocket.  The pounding of the chain going over the sprocket flattens out the inside half of the bushing making a taper, and the sprocket wobbles.  This makes the chain loose as well as forcing the shift collar to jump out of gear, wrecking the pads on the shift fork.  The sled is now locked in reverse.

 

The solution here is to press out the bushing in the sprocket and replace with a leaded bronze SAE 660 bushing or better yet an aluminum/bronze bushing.  The bushing is 1" ID, 1.125" OD x 1" long.  Once pressed in the gear, cut to length flush with the gear and de-burr.

 

I hope this has cleared up any misconceptions with the chain case.  Anyone that opens it up once a year to change the fluid can easily address this and ride with piece of mind.

Edited by Big Pussy
  • Like 2

Share this post


Link to post
Share on other sites

Both of his lost reverse on one and drive on the other. Have not had the chance to look hard into one but neither of your solutions seem to resemble this problem. I had to try and move the srx out of my trailer and it seemed to be a shifting issue because of the noise. As it was warranty I did not look. The gears stripped on the spline if that makes any sense . Something about the shifting fork not moving them over enough. 

Share this post


Link to post
Share on other sites
Quote

The biggest problem is the two flat head screws holding the axle for the chain tensioner wheel come loose and the the axle spins and the screws fall out. 

 

A while back I must have not put enough 271 on the lower gear [bolt] on my older Doo, and as it came loose, eventually the head bottomed out agginst the outter case half, and then broached the most beautiful hex through the case that y'ever did see...

 

Edited by Ox

Share this post


Link to post
Share on other sites
2 minutes ago, Motorhead said:

Both of his lost reverse on one and drive on the other. Have not had the chance to look hard into one but neither of your solutions seem to resemble this problem. I had to try and move the srx out of my trailer and it seemed to be a shifting issue because of the noise. As it was warranty I did not look. The gears stripped on the spline if that makes any sense . Something about the shifting fork not moving them over enough. 

Oh yeah ... this is the 4 stroke Kitty?

 

Yeah, my chum told me that the M11's had that trouble, and that the later ones were s'posed to be more better.

 

Something aboot guys having to back them all the way back to the truck as they couldn't git it into fwd anymore?

 

Then one day when we were riding together, I heard the problem myself:

 

He also has 2st Doo's and is very familiar with RER, but the mechanical gearcase is different, and most don't give it the care that it needs.

I'm not talking PM, I mean care as in baby-ing it into the shifted gear.

 

When you shift a mechanical reverse snowmachine, you need to burp the gas a wee bit to let the gear splines line up and drop where it's to be. 

This is no different than how snowmachines were before RER, just that reverse is WAY more popular now than back then.

 

Remember - burp the throttle a bit. Maybe even a cpl times before you give'r, to let that gear slide in where it's to go.

 

 

.

Share this post


Link to post
Share on other sites

Maybe the bushing is the closest one of your solutions.  If it does flat spot and damage the shift fork pads that could be it. It's still a pain that he spent over $40000 since 2014 on two yamicats. And they can't make the right changes on a 2019 srx. Oils and what not are not a factor in this. This is poor engineering. 

I on the other hand only have to change engines. Lol

Share this post


Link to post
Share on other sites
8 minutes ago, Ox said:

Oh yeah ... this is the 4 stroke Kitty?

 

Yeah, my chum told me that the M11's had that trouble, and that the later ones were s'posed to be more better.

 

Something aboot guys having to back them all the way back to the truck as they couldn't git it into fwd anymore?

 

Then one day when we were riding together, I heard the problem myself:

 

He also has 2st Doo's and is very familiar with RER, but the mechanical gearcase is different, and most don't give it the care that it needs.

I'm not talking PM, I mean care as in baby-ing it into the shifted gear.

 

When you shift a mechanical reverse snowmachine, you need to burp the gas a wee bit to let the gear splines line up and drop where it's to be. 

This is no different than how snowmachines were before RER, just that reverse is WAY more popular now than back then.

 

Remember - burp the throttle a bit. Maybe even a cpl times before you give'r, to let that gear slide in where it's to go.

 

 

.

I will tell him that. Surely that must be in the Yamicats owners manual somewhere. Lol.

I have a 2016 1200 that I just pull the lever and go. 

Share this post


Link to post
Share on other sites

Well I recommend that for any reverse gearcase.

Maybe the Doo holds up better, but ...

 

 

It's been 20 yrs since I was in my '96 Grand Touring case, but it seems like Doo had a cpl 1/2" pins that dropped into holes, and not have to line up two sets of splines?

Share this post


Link to post
Share on other sites

The top chain sprocket has the bushing inside it and it rides on the inside of the top jackshaft.  The right side of this gear has small pointed teeth on it just like in a manual transmission.  To the right of this is the sliding shift collar and reverse gear, splined to the jackshaft.  The shift fork on this sliding gear holds the collar against the top sprocket driving it forward.  So the top sprocket and the jackshaft are now turning together, so there is no relative movement of shaft to sprocket.  So the bushing does not wear by turning, but by the harmonics of the chain and sprocket.

 

The gear change shifting motor is a 2005 Saturn passenger side power window motor.  It turns a pinion which moves a rack that shifts the fork.  The worm wheel in the motor is plastic and strips just like the garage door opener does.  This is also a problem because it is too hard today for anyone to run a shift lever.

 

When the top sprocket bushing is worn, as mine is right now, the sprocket is running at an angle which pushes the shift collar away and damages the shift fork.  Then it is stuck in reverse.  Mine has not gotten to this point because I did a yearly inspection and found it in time before the shift fork got damaged.

 

So the whole design is a POS.  The 199x to 2004 design was bullet proof and had the three spring loaded pins to engage the bottom drive gear.  That would not work now since riders right hands are not up to the task of pulling out the shift lever and pushing it back in.

 

The magnets on the bottom shaft are the speedo signal.  The pickup is in the outer case.

 

The bottom picture shows the shift collar/reverse gear and fork removed.  You can see the engagement teeth on the outside of the top sprocket.  You can also see the flat head screws on the tensioner bracket.  TIG weld the screw head to the bracket on each side so the screws cannot come loose.

 

Both bottom sprockets are splined to the output shaft and rotate together.  In reverse, the top sprocket turns backwards on the jackshaft, and that is why there is a bushing in there.  It is not hard enough.

 

 

IMG_4711.thumb.JPG.d0286312ddfdc7ee1a066b8819e5fe95.JPG

 

 

 

IMG_4704.thumb.JPG.07a371dd629b6f30824495cf9df29c4c.JPG

 

 

 

Edited by Big Pussy

Share this post


Link to post
Share on other sites
6 minutes ago, Big Pussy said:

That would not work now since riders right hands are not up to the task of pulling out the shift lever and pushing it back in.

 

 

 

 

 

 

 

 

 

 

Same goes for transfer case shifters.... :angry:

Share this post


Link to post
Share on other sites

Wow great pictures. I will suggest the better bushing material to him. Again he was hoping they would have debugged there system after 5 model years. Thanks for the dimensions and tip . Also can tease him about the Saturn shifter.

 

 

Share this post


Link to post
Share on other sites

There will be no changes made until the next chassis is made, if that ever happens.  I can only assume that it will be worse based on the kids designing with Solid Dick using FEA to test things out.  They obviously have never fixed a sled, and maybe never rode one either.  The old boys have been forced to retire so there are no wise ones watching anymore.  So I have taken on the task to re-engineer the thing to make it reliable.  1700Km this year and it drove out of Quebec on it's own power.  Currently apart in the garage waiting on bushings from McMaster-Carr.  May be waiting a long time.

  • Like 1

Share this post


Link to post
Share on other sites

If you look close on the top picture in my last post, the right side case is off the engine.  This was to see how things work inside and understand how and why the starter idler gear and the starter shaft teeth have been breaking.  I figured that out too.  Note that the design of the magneto is backwards to old 2-stroke engines.  The flywheel is mounted backwards and the stator is mounted to the case.  I never had a starter gear failure to this day because I always held the key until running.  I also got the ECM re-flashed twice on my 15 7000 until they got it right and now it runs like a Cat-ilac.

 

If I have a problem or hear of  a problem, I investigate instead of just bitching and complaining.  This investigation cost me $16 for an engine case gasket.

 

IMG_4708.thumb.JPG.e55bd80ad4d9b8580236954dc52e3688.JPG

 

IMG_4715.thumb.JPG.d57d0c67fc7d8d248842ea806c25e444.JPG

 

 

 

Share this post


Link to post
Share on other sites

Your very thorough on your mechanical analysis.  Have to wonder why the average rider would buy one without this knowledge. Not a fan of dealers that slap back in the same old parts till the warranty is up. Gotta wonder about that key thing . In this day and age holding a key till it runs is primative. My friends are all so spooked about the kick back if you let it go premature. I will check the Mc master Carr site out. Love that place.

Share this post


Link to post
Share on other sites

What a joke, $20 k for a sled and you have to worry about that crap

I currently drive a 16 Apex and will be my last Yamaha

  • Like 1

Share this post


Link to post
Share on other sites
23 minutes ago, GTC said:

What a joke, $20 k for a sled and you have to worry about that crap

I currently drive a 16 Apex and will be my last Yamaha

Or can ride a $16k doo and worry when the motor is gonna go down. Pick your poison. 

Share this post


Link to post
Share on other sites
32 minutes ago, GTC said:

What a joke, $20 k for a sled and you have to worry about that crap

I currently drive a 16 Apex and will be my last Yamaha

Make sure you get a backward running 2-stroke.  That way there is only a chain a two fixed mounted sprockets.  What could go wrong ?  Then you will only have to keep the engine together.

  • Like 1

Share this post


Link to post
Share on other sites
7 minutes ago, Big Pussy said:

Make sure you get a backward running 2-stroke.  That way there is only a chain a two fixed mounted sprockets.  What could go wrong ?  Then you will only have to keep the engine together.

Come on guys. Every manufacturer has its pro’s and cons. Skidoo has those sealed crank bearing engines, funny I never blew one up with almost 13,000 km’s . Next guy can’t get 5k before engine blows. Same thing with these chain cases. Some have luck and some don’t. Maybe adjusting chain every once in awhile helps too. Seems to be some tricks too. Bad engineering is out there every where. After all we want everything at a reasonable cost. 20k for a sled too isn’t bad when we paid 10k in 90’s for a sled that ate gas and oil and had no suspension and some of triples only liked to go straight. 

Edited by Strong Farmer

Share this post


Link to post
Share on other sites
1 hour ago, Motorhead said:

Your very thorough on your mechanical analysis.  Have to wonder why the average rider would buy one without this knowledge. Not a fan of dealers that slap back in the same old parts till the warranty is up. Gotta wonder about that key thing . In this day and age holding a key till it runs is primative. My friends are all so spooked about the kick back if you let it go premature. I will check the Mc master Carr site out. Love that place.

Some times the manufacturer controls what warranty replacement parts are used for replacement either by availability of the replacement part, by only reimbursing dealers based on what part was installed or by dictating what is to be used. Sometimes, even though manufacturers have announced an updated part to the dealer network there may not be sufficient inventory of the part available. This can be caused by too much demand for the new part or by the manufacturer making the announcement before any quantity part is actually available through the parts network.  Some dealers may put the original part back in because they have it in inventory and don't want to eat the investment they put into it. Manufacturers do not normally allow dealers to return unused parts for full value if at all.

Share this post


Link to post
Share on other sites

Hey, don't shoot the messenger.  I am only pointing out what is wrong AND how to fix it.  I own one of these chain cases as does my son.  Therefore I fix them both.  It is definitely a weak part of the sled, but if serviced yearly with a $3 bushing, a tension adjustment, and an oil change, it will stay together.  Not sure if it will at sustained 200Km/hr like some want to do, but for this old guy it does.

 

I have had my share of 2-stroke engines cold seize, piston melt, loose rod, broken stator, cracked flywheel, etc, etc, etc.  I know how to fix them.

  • Like 1

Share this post


Link to post
Share on other sites

I can accept that a two stroke is basically a ticking bomb . No surprises. A little disappointed that the 850 is not what skidoo made it out to be.  Not any better than the 800. I traded my 2014 800 in running with near same km that mine blew. 10000km .

Going to keep my 1200 for a long time .

Share this post


Link to post
Share on other sites
1 hour ago, Motorhead said:

I can accept that a two stroke is basically a ticking bomb . No surprises. A little disappointed that the 850 is not what skidoo made it out to be.  Not any better than the 800. I traded my 2014 800 in running with near same km that mine blew. 10000km .

Going to keep my 1200 for a long time .

Why 850 blow. Are you saying those have sealed iso crank bearings too and aren’t lubed with injection oil like ads claimed when it was introduced. Many bought the 850’s for this very reason and extra durability that was promised in ads? Inquiring minds want to know. 

Edited by Strong Farmer

Share this post


Link to post
Share on other sites
2 minutes ago, Strong Farmer said:

Why 850 blow. Are you saying those have sealed iso crank bearings too and aren’t lubed with injection oil like ads claimed when it was introduced.

The main bearings are lubed by the oil pump oil directly.  I don't think that is the problem.  Due to the two piece forged crank assy. pressed together in the center, there is no way to assemble the rods on the crank pins.  So the rods have a bolt on cap like a 4-stroke BUT with needle bearings in there.  That is what exploded in the early engines cutting the crankcase in half.

 

Maybe Motorhead can elaborate on his engine failure instead of "my  engine blew up".  Like you said, inquiring minds want to know.  Doo problems seem to hushed up.  Lay it bare !

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...