150cc peace sport tpgs 804, piston By fox83 (Read 7,502 times)

[fox83]

I've tried from all the way in to slowly moving it out. But that didn't work. Idk my brother wants me to find out what the gaps on my rings are supposed to be. Also how much compression its suppose to have

[czmdiver]

Aug 17, 2015 2:30:12 GMT -6 fox83 said:

I've tried from all the way in to slowly moving it out. But that didn't work. Idk my brother wants me to find out what the gaps on my rings are supposed to be. Also how much compression its suppose to have

Ring End Gap Rule of thumb,  .003-.004 per Inches of Bore.  Min.
Round off to 2" bore would be .006-.008  Minimum  If yours is correct will be .010-.012
Don't get all caught up in this spec, I can run .015-.020 on the Top (compression) ring and they still have Tons of Compression and Run Fine.
If you do have a End Gap of upward of .020 that is telling you one a couple things.
(1) The Bore is Severely Wore Out/Egg Shaped and now you've lost your piston to cylinder clearance and End Gap clearance.
(2)There the Wrong Rings.
Now Ive seen Rings severely wore down to looking like a wire that would cause compression loss and excessive ring end gap but it always destroyed the piston to.
Compression Low is under 100, It Will start and run with 90psi.
Most like to see in the 120psi area.
IF no gauge stick your finger/thumb in the spark plug hole, should blow you finger/thumb out.

[fox83]

Ok thank you. I just don't get what's wrong she sounds like she wants to run just won't fully turn over.we can get it to were its picking up like its runnong but you let go of starter and there's nothing

[fox83]

Oh and its a brand new jugg and piston. Brand new head new cdi new stator new spark plug. New carb. All new gaskets smh idk

[czmdiver]

Aug 17, 2015 8:43:18 GMT -6 fox83 said:

Oh and its a brand new jugg and piston. Brand new head new cdi new stator new spark plug. New carb. All new gaskets smh idk

Yup! Ive been reading along on your saga

[Alleyoop]

Sure sounds like low compression from what was just said. Do the compression finger trick remember HOLD THE THROTTLE WIDE OPEN and crank it. IF it lifts your finger off the hole it has descent compression if you just fell some pressure then you have a problem.
Alleyoop

[fox83]

[fox83]

Ok it doesn't lift my finger but its close. That's my rings right?

[Alleyoop]

The video is set to PRIVATE we cannot see it, Change the setting so we can see it.

And if it did NOT lift your finger off then lets see which it is VALVES or RINGS. Do the finger test again BUT THIS TIME ADD a TABLESPOON of OIL down the plug hole and do the compression test again.
Alleyoop

[fox83]

Ok fixed vid

[Alleyoop]

That intake manifold is loose on the motor, that effects the ability to suck in gas. So tighten up the intake manifold so you do not have a leak there. The other thing I noticed is you do not have a AIR FILTER on the carb that will effect the sucktion of gas into the motor do this is Cover the Air Filter intake with your hand and see if it then fires.
Alleyoop

[fox83]

I took air filter off to try to start it that way today with no luck

[Alleyoop]

Are your sure the plug is FIRING? If you have fuel, air and spark it should at least FIRE. If after cranking the plug is wet then the plug is NOT FIRING.

[fox83]

Plug not really getting wet.smells a little like gas. But im 100 % sure its firing it was arcing about inch and a half to the head and the starter button shocked the crap outta me lol



Its popping like its firing just doesn't run. Immature change the rings tonight I think I put the one ones on the new piston...I think I have to make sure

[czmdiver]

I'd beg borrow or steal a psi gauge than take the top end back down. local auto parts store rent one?
The chance that on a New Top End kit, there is something very wrong with the rings is Highly Unlikely.
you can get away with some real slop in there and she'l start and run.