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Discussion Starter #1
Hi, I was just trying to figure this 1978 Ski-Doo Olympique, and it seems to really bog when starting out on any incline whatsoever or when I'm in even two or three inches of snow. I noticed the drive belt is riding about 1/4" below the level of the secondary clutch, and I read it should be ideally 1/8" above the secondary clutch. Would this make a big difference? Kind of like starting in 2nd gear in a car? That's what it feels like, for sure.

I'm not sure how to make that adjustment, though, I cleaned the clutches, verified the belt size, measured the pulley distances and everything looks good. The only other thing I can see is the secondary spring being too weak to fully close the sheaves so the belt sits higher... so is that the next thing to try? Or is there some other method of adjustment...... or do you guys think it won't make much of a difference and my problem is elsewhere......

Thanks for any insight, really appreciate it
 

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With the belt off, is the secondary fully closed?
Have you compared the width of the belt with a new one?
An old worn belt will give the same results as a mis-functioning secondary.
 

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Discussion Starter #3
Secondary is fully closed when the belt's off... the belt is new, not worn at all... it's an aftermarket belt I matched to the original belt listed in the owner's manual.... Dayco 3019 for the '78 Olympique. So that's what I've been going with.......
 

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So, when you put the new belt on, it does not ride up on the sheaves?
The belt may be too short.
Can you compare it to the old belt for length?
 

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Discussion Starter #5
There was no original belt when I got the Olympique, but it in the manual it said to use the Bombardier 414-2327 belt, which I don't have. I matched that with the Dayco belts, and that model number matched the Dayco 3019, so that's what I've been using. It's the same width as the manual says, 33mm, but there is no length listed so I'm not sure how long the 414-2327 belt should be... I assumed it would be the same but I should find a way to verify the length of the 414-2327 belt

(Know any guide that might list this kind of info, off hand?)
 

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Test by checking belt deflection.
Use a straight edge laid across the two clutches and press down on the belt. Measure the distance (should not exceed 1 1/2") from the straight edge and the top of the belt.
 

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Discussion Starter #7
The belt tension is pretty loose, the deflection is closer to 2 1/4"... so I think the belt length is OK if the belt were riding slightly above the sheaves, probably the deflection would be around 1 1/2", like it should be....

Is it possible a weak spring would cause not enough pressure to raise the belt above the sheaves, or is that really unlikely

(I think the spring is 32 years young)
 

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When you look under the belt, is the sheaves fitting tight together? (clutch is closed completely)

If so, then it is likely that the belt is either too long, or just too worn (narrow).
 

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Rick
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i would get a new spring if it is that old
 

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Discussion Starter #12
Ok, I'll try and hunt down a new spring and see if that helps, I measured every other distance I could and it looks good, so that's the only other variable I can think of.

The dealerships I've asked can't track down the spring for the '78 Olympique, but maybe I'll have some luck in the next few days. I'll keep tryin'.

Thanks guys
 

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Rick
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look on ebay but don't get a used one. or even take it out and see if a dealer can match it up.
 
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