yamaha moto 4 no compresion and has good rings

[aftrmath99]

i have a yamaha moto 4 that has no compresion  i checked and the rings and cylinder are in great shape  if it is 180 degrees out  will that cause this problem or can anyone tell me what would cause this  i had a sticky valve but i cleaned it and its working good

[TOY_DOCTOR]

180 out of time will not do that, a bent or sticking valve will, or the timing not set right will also..

[Chuck_Norris]

when you say that you have compression, by what means have you measured it. second is there a possibility that you may have washed the rings down. if that is the case, take some spray lube,trans fluid and or oil and put a smal amount into the spark  plug hole, rotate the engine a few times and see if there is any improvement.

[Old_School]

Did you replace the rings recently? Is that why you said it has good rings? If you did and didn't bore it over and put in a new piston you may have broken a ring gland or ring. Time to pull the head.  -Mark