New Belt ????s

tjmoening

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Dec 16, 2009
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Minnesota
My 1992 Yamaha Exciter II LE was making a slight thumping noise and a jerking feeling on takeoff and at very slow speeds. I put a new belt on the sled and it fixed the thumping and jerking. The sled has a smooth takeoff now. The old belt seemed in good shape but was concaved on the edges a bit, so I bet it was just slipping a bit at slow speeds causing the thumping feeling. Now my sled idles very low (Around 1000 rpm) and seems on the verge of stalling at idle. I am assuming the new belt is more snug on the clutch. Will this new belt break in, should I adjust the carbs up a bit to bring the idle up or should I just leave it since it does not stall, just idles extremely low? This shouldn't hurt the engine or foul my plugs at all, should it? It was idling at 1400-1500 rpm with the old belt on. Thanks for any help.
 

The belt was not slipping but had a burned spot on it. That was why it was jerking and thumping. If you look close you should see it.
 
x2 on old one being burned.

you are shure it is the right belt? my enticer would get the wrong one because the books had it listed as the wrong width for over 5 years. they fixed the books recently but it was a good thing that it had happened to me before.

if it tries to move when you turn the idle up, it is the wrong width belt. also clean your clutch faces with steel wool or emory cloth so it does not burn the new belt as well. bet they are glazed bad.
 
The old belt was glazed on the edges and also concaved which is normal wear I would think. Could I use brake parts spray cleaner on the clutch to clean it up? That stuff really cleans up brake rotors nicely, I bet it would work great on the clutch. Maim, is there anywhere online that would have the "for sure" belt size for my sled? I just ordered the replacement belt from Dennis Kirk assuming that they had the correct size for my Exciter. The belt from them seems to work fine, just seems to slow my idle way down like it is too tight/wide for the clutch. Thanks for any help guys.
 
the brake clean will just remove the belt dust and leave a film on your clutch. you need to polish the clutch faces with 220grit sandpaper or steel wool to rough them up a bit and blow it off with compressed air. this gives them more grip so that they do not slip as easily on the belt.

if you have another belt around for a yamaha sled, try it or compare it to the one you bought. most yamahas have the same center to centre and profile. compare it to the new one you have. if the new one is visably wider than the old/other one (1-2mm wider), you might have gotten the wrong belt.

there is a doo belt that fits and lots too wide as the clutch will not disengage at all. only have 1 doo at home and it happens to be the one that does this. yam belts work finr to get it home though.
 
The clutch faces are glazed and shiny, not rough at all. I will take your advice and score them up a bit with some 220 grit. I rode around a bit today with that new belt on. The sled seems to go OK with it on, but at times accelerates slow and seems to have less mid range then it did with the old belt. I also noticed the new belt is already slightly fraying on the inside edge. When I line up the frayed area on the clutch, when the sled is running, the sled idles higher and better. If the frayed areas are not on the clutch, the sled idles at 1000 rpm or less. I'm starting to think the belt is a bit too wide. I'm hoping it will break it, because it is the recommended belt for the sled. It was a Parts Unlimited belt though, not an OEM Yamaha belt. Thanks again.
 
I scored up both the primary and secondary clutch faces with some emery cloth. Both were glazed and shiny, probably never been touched since the sled was new. The old belt was burnt in at least one spot. You can see where the clutch had glazed and even created a groove in one spot. I roughed that belt up as best i could and put it back on. The sled still jerks a bit at slow speeds. I think the belt is just too glazed in that spot. I could feel a difference mid range though. When I could get good traction, pulling the skis off the ground was easy. You guys think a new "Yamaha" belt would eliminate the jumping? My generic new belt I think is too wide. thanks for the help!
 
yes a new yamaha belt would stop the jumping. when you get the new belt, compare it to your aftermarket one. i will bet you that the aftermarket bet is too wide.

now go ride that puppy and enjoy it. i only have 2 weekend left to enjoy myself as knee surgery is on feb 18. joy.
 
Now the Exciter has a new issue.....severe bogging!! The sled was running great and strong, then all of a sudden it started to bog horribly! The sled starts up great, idles nice and takes of smooth, but once I give it a little gas, it bogs down and will not accelerate. It almost seems like it is running on 1 cylinder. If I take the belt off, the sled revs up great, the clutch compresses and decompresses with no problem. Once I put the belt on, and rev her up so I am moving it bogs down, usually at 4000-5000 rpm. I checked the compression to make sure it wasn't a motor issue and both cylinders are at about 121-122 PSI, so it has good compression. Could it be a broken clutch spring? The primary clutch seems to operate right, the secondary clutch looks ok, but has quite a bit of play in it on the bolt. I can move the whole secondary clutch around probably 1/4 -1/2 inch in any direction. Is that normal? I asked a guy at a shop and he said it sounded like a broken clutch spring. Any ideas from anyone? Is a new clutch spring spendy to fix? I don't have a clutch puller or a clutch tool to do the work myself so I will probably bring it in? Any ideas? Thanks!
 
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Sounds to me like you need to check your belt deflection, that is, where the new belt sits in the secondary. It should sit flush or about an eighth above the top of the sheaves. If it is sitting down too far it is like taking off in second or third gear, which will cause a bog. It's also possible that the new belt is already ruined from being the wrong length or width and being ran that way. To check deflection, raise the back end of the sled up and then rev it up until the clutches are spinning, and then just let it coast back down to a stop. Don't use the brake, as that will mess up where the belt will come to rest. After doing this, see if the belt is sitting at the top or a little above. If it's sitting down too low, you need to remove the secondary and on the back there are three bolts (I think exciters are the same as mine, anyway). The way you adjust is by adding or removing washers on the bolts. The farther the bolts goes into the clutch, the lower your belt will ride, and vice versa. If your belt is sitting too low in the clutch, you're going to want to add washers (the same amount on each) to reduce how far the bolts go in. This will allow the sheaves to sit closer to each other and squeeze the belt up higher on the clutch. It is also possible for the ends of the bolts to wear down over time, and it's best to just buy new ones and start over.
Another possibility since it ate a belt, and now seems to be eating the brand new one: a motor mount has broke. If this happens, the motor torques the clutches out of alignment, which eats belts like mad and can cause the bogging your experiencing. With the clutches out of alignment, the side tension from mis-aligned clutches causes the belt to hold them out of alignment even when slowing down, and then when you hit it again it hasn't down shifted so its like trying to accelerate in too high of a gear. These two places are where I would start, anyway. Good luck.
 
I was out messing with the sled and I think I found the source of the problem. The upper idler bearings were froze on the suspension. The suspension wheels on both sides are darn near froze up and and the wheel on the left side is pretty much gone, no rubber left and the metal on wheel is even wearing. I can turn the wheels on the rod, but it takes a great deal of effort and like I said, the wheel on the left has virtually nothing left of it, down to the metal and then some. Does this sound like it could be the source of the bogging problem? My guess is the motor was reving up and trying to gain speed by shifting, but there was so much drag from this idler that the motor would shift and not have enough juice to pick up speed because of this drag from these froze wheels. Does this soud like it could be it? Thanks for all the help fellas!!!
 


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