Engine Trouble Recently Rebuilt engine won't start

[crassius]

note my thread in which I was trying to find a compression leak, but the hissing sound was coming from a bad valve in the gauge

 

[SpeedBoi]

Alright fellas I think its the piston rings not sealing, but I'm just gonna go ahead and replace the whole top end because I'm not exactly sure which part is causing the issue. This thing makes me wanna pull my hair out sometimes

 

[SpeedBoi]

is there a proper way to install these piston rings, or do they need to get hot first?
because right now when I turn the engine over with a wrench I can see air slipping past the piston rings, causing my lack of compression

 

[crassius]

the rings have a cutout at the ends that is supposed to fit around the locating pins and meet (somewhat) at the bottom of the pin

a dry ring won't make a perfect seal, it needs the fuel/oil mixture to help it out a bit (note: when a motor has an overly high compression reading, I usually check for too much oil first)

 

[KCvale]

I just replaced the cdi and stator coil on the bike, as well as getting a new spark plug. I got spark

you really need a compression check

what gaskets did you make???

If you are pulling your head, do you have a torque wrench to put the head back on torqued correctly?

5# at time in an X pattern to 20# is what I run.

 

[SpeedBoi]

No, I do not have a torque wrench, but I've taken the head off before and when I put it back without a torque wrench it did just fine. Maybe Ill go get a torque wrench today

 

[KCvale]

No, I do not have a torque wrench, but I've taken the head off before and when I put it back without a torque wrench it did just fine.
Maybe Ill go get a torque wrench today

I highly recommend you do so especially when tracking a compression problem as that is the first place to look.

 

[SpeedBoi]

Okay so today I fully rebuilt the engine again putting in factory gaskets, the crankcase seals look good to me, I also have a brand new cylinder, piston, and piston rings. Ill let you guys know whether that fixed it or not

 

[SpeedBoi]

no good, only reading about 40psi, I don't understand what could be going wrong. I mean the head gasket looks like its not sitting completely flat but could that really cause a difference of 60psi?

 

[HumanPerson]

I'd check my bearing seals under the magneto magnet and armeture and the other side under the bevel gear for any leaks at all.
If you were to have a bad seal your compression would be lowered substantially.