1999 Vmax 600 Triple not revving out

Michael.h

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Hi everyone.. got a 99 Vmax 600 triple. Ran fine until late last year when it stopped revving out.. ie only gets to about 7000 and then starts running like shite and bogging. Carbs are clean, TORS is disconnected, spark seems good, good compression new crank seals, brake not stuck, air screws@1.5, and floats set ~15mm. Sled starts, idles and sounds great and moves fine at low speed but makes no power and wont rev out.

Thinking it could be needles/seats flooding it out, weak primary engaging clutch too hard, or possibly spark leak somewhere. Going to be pulling the clutch to tighten the ring gear back up as it rattles badly anyway, so are there any specs to which I can test if the primary spring it bad or not? Any ideas??? Thanks
 
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Maim

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throw a new primary spring in it as they where $20.00

make sure you use green lock tight on those ring gear bolts or you will end up like me, on clutch #3 in under 5000 mi. did a mod to mine and it seems to be holding well.
 

Michael.h

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throw a new primary spring in it as they where $20.00

make sure you use green lock tight on those ring gear bolts or you will end up like me, on clutch #3 in under 5000 mi. did a mod to mine and it seems to be holding well.
Just raised track off ground and tryed to rev again... Still same.. Do you think it would still be primary spring even if it doesent rev when track off ground? I would think it should spin no matter what if the track of off ground. Starting to lean towards fuel issue

thanks
 

Maim

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ok, it might need new fuel filter in the tank but if you do not know the age of the primary spring, a new one would not hurt.
 

MURDER YAMAHA

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try it again on the stand, this time when it wont rev, slowly apply choke and listen for pickup in rpm or drop off.
What do the plugs look like ?
Slowly pull the recoil cord, do all cylinders feel like they have the same amount of compression?
 

Michael.h

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ok, it might need new fuel filter in the tank but if you do not know the age of the primary spring, a new one would not hurt.
yeah if I can get my hands on one il definitely put one in to be safe. Sled has 25000km on it unsure if it was ever rebuild or not. Probably could use one anyway.
 

Michael.h

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try it again on the stand, this time when it wont rev, slowly apply choke and listen for pickup in rpm or drop off.
What do the plugs look like ?
Slowly pull the recoil cord, do all cylinders feel like they have the same amount of compression?
Tried choking it when running earlier and made it worse. Sled has even compression and had a new crank seal last year and doesent seem to have any other air leaks. Il try choking when off ground id think it would rev even if its not getting a ton of fuel because it takes less throttle and fuel under no load to rev up. Good Idea Thanks
 

Michael.h

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Tried choking it when running earlier and made it worse. Sled has even compression and had a new crank seal last year and doesent seem to have any other air leaks. Il try choking when off ground id think it would rev even if its not getting a ton of fuel because it takes less throttle and fuel under no load to rev up. Good Idea Thanks
Same result.. Going to look at fuel pump and needles and seats
 


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