Crank out of phase

MURDER YAMAHA

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Age
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Location
Minot ND
My buddy has a 1997 700 redhead.
Is running ok, but 8 mph slower than the same setup that’s in my MM700.
They checked crank tonight with a degree wheel, and found its 5 degrees off on PTO.
This enough to be a problem?
 

Not sure runout is relevant if its 5 degrees off already.
Wondering if 5 degrees is far enough off to cause problems with power.
 
I am curious how it was checked with a degree wheel? Are you using something down the plug hole to find tdc or is the crank out and sitting on a bench? It is hard to be precise when putting something down the cylinder to find tdc so it would be easy to be 5 degrees off. The same sled with the same setup doesn't mean the speeds will be the same. There are a lot of things that can change the speed of the sled.
 
It could easily be done with a dial indicator or the piston stopper method (like a thick peace of solder for example) Both will find your true tdc of each piston when used in conjunction with a degree wheel.
 
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I wasn’t there when they did it, but i think they had something in the cylinder.
I have always used a long 3/8” extension. Fits perfect, and easy to see.
They pulled the crank out, and are going to use a spare crank that I had.
 
It could easily be done with a dial indicator or the piston stopper method (like a thick peace of solder for example) Both will find your true tdc of each piston when used in conjunction with a degree wheel.
I agree. But if they were simply putting a rod down the plug hole and marking the rod it could seem off when it is not because you can roll the crank a bit without the piston moving much at all when it is tdc.
 
I agree. But if they were simply putting a rod down the plug hole and marking the rod it could seem off when it is not because you can roll the crank a bit without the piston moving much at all when it is tdc.


Agreed
 
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Think they said its about 3/8" with the primary clutch on, marking it on the frame and the clutch.
 


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