tjsands12
New member
i just got my sled back from the yamaha shop to get the carbs cleaned. i get a phone call back saying that my compression is pto 110-center 115-mag 124. they baisically told me that my sled is on the edge of surviving and reccomend either rebuilding or buying another motor. the sled runs just like it did last season. it only has 2800 miles on it. he also said that my compression is prob like that b/c of the stock jetting with my bender 4x4 pipe. any opinions??
daman
New member
Them shops are joke!!!
did you ask them HOW they did the test and if a leak down test was done because they had a concern?
did you ask them HOW they did the test and if a leak down test was done because they had a concern?
YAMMIEGOD3:16
Active member
YA, HAVE THEM THROW A NEW MOTOR IN FOR YA. SOUNDS LIKE ONE OF THOSE CAR COMMERICALS. '' YOU CAN PAY ME NOW OR PAY ME LATTER ''. 3:16 (yammie tony)
staggs65
Moderator
agreed, just ride it
daman
New member
Lol Tony.....YAMMIEGOD3:16 said:
The viper runs stagered comp to allow straight jetting. The old sleds ran stagered jetting and the same compression. This si from memory but someone will correct me if I am wrong Maxdlx
maxdlx said:
Yeah, thats correct. A dealer should know this.
Find a tester and check it yourself, let us know what you find. The bender 4x4 called for stock jetting.
harness racer
New member
tjsands12 said:
the dealer says the compression is relative to the jetting !!!!!!!something is wrong here ...go back and get that on tape recorder ....I d'ont beleive it !!!!
or are they saying your running lean and the piston is rounded off on the exhaust side , sneaking under the rings ?
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livewire_101proof
Member
Not sure on exact numbers but i think 2 sound a little low, but i thought that they dont need to be all the same, can be staggered but should be within a few lbs of eachother. Not an expert though probably somewone else will have better info for ya. I would say even if it is weak its nothing rings and a hone job cant fix and that wouldnt break your wallet too bad as far as parts go anyways. Most of them yamaha tripples go a long ways though with no problems if good gas and oil are used, i have about 7000 miles on my 2000 srx and there are many people on here with alot more than that. Good luck.
#2 is a little low but not terrible. Mine ran 110 pto and 118 on the other 2 and I put pipes on it and rode the DS out of it. When I switched to mega heads, it ran 120 straight across, which made me think it was just how I checked each cylinder when stock. I'd ride it like it is, but for piece of mind recheck it.
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daman
New member
Vipers have staggered compression like said above, lower on the PTO side you want to see around 118 pto and 120 and above on the rest.
fully warmed up throttle open 5-6 good pulls...doing it three times per cyl for a average.
fully warmed up throttle open 5-6 good pulls...doing it three times per cyl for a average.