motor toast

[srx901]

I have a 2010 Nytro with 8000mi. I have been having idle issues and have looked for vacuum leaks and isc valve problems ect I checked what the sled was puting out for vacuum and the needle on my gauge was going between 0 and 5 psi fluctuating fast. so I did a compression test and I get 125 on all three cylinders and I read on here that that is too low so I either have blown head gasket between all cylinders or my rings are shot. Ive had many two strokes with more miles and they are much easier to rebuild . Has anyone else have this problem and how hard is it to remove motor to rebuild top end.

 

[Confused]

Even is good. Check it with another gauge.

 

[Mills]

Compression on Nytro motor is supposed to be 213 psi per the local Yamaha shop service technision

 

[SnoBird888]

normally when you get a nice even compression reading that is a good first sign. Next would be to test it against a different gauge to see. I have a tester that is always 30-35% low compared to a snap on or higher end I have tested it against. I just know this for when I check my own stuff.

 

[Mills]

The other thing that could have happened is your timing chain could have jumped a tooth or two causing the valves to be slightly open during the compression stroke. Has it ever backfired really hard or been stopped suddenly somehow?

 

[srx901]

The other thing that could have happened is your timing chain could have jumped a tooth or two causing the valves to be slightly open during the compression stroke. Has it ever backfired really hard or been stopped suddenly somehow?

I dont remember it ever backfiring or stoping quick could have bad exhaust valves I supposed. I need to put capfull of oil in cylinder and recheck compression to check rings