84 110 wont start/run

[FATTYFIVE]

120lbs comp. spark seems good. fuel directly into cylinder, no manifold. Turning over with 110v screwgun at the mag. Will not even pop. Had piston out & rings ---good. new gaskets installed. valves adjusted. Flywheel pulled. Cleaned stators---good. Cleaned up inside of magneto--light sanded. NO FIRE:cry: Any help will be great.>:beer

[FATTYFIVE]

Never mind. Just found the manuals. Looks like the comp. is down. Would this reading of 120 be too low to get it running? Last year It quit running. Would not fire up unless we pulled it, Then, full throttle just to keep it going. Im guessing its new piston time.

[FATTYFIVE]

Spits alot of fuel out of carb when i throttle it during startup(with screwgun)

[FATTYFIVE]

Anyone? Piston sound right? Im usually messing with 2 strokes, so Im not 4stroke literate.

[CRAZY70MAN]

My 83 110 has only 130psi comp and it runs, a little sluggish though. Carb problem maybe?? Maybe valve adjustment?? Good luck. Plent of help and manuals on here for ya.:beer

[FATTYFIVE]

Went thru carb, all jets and passages clear. Valves were adjusted, first very loose to check comp. then to correct spec. No dice.

[DeePa]

its gotta be spark so ohm out your components, check for ground, and make sure its timed right

[FATTYFIVE]

Went thru manuals on here and it keeps locking up. Do you know off hand what the coils should be at? Good Gound. Timing is fool proof, No? Looks to only go one way to me. Other than cdi timing. Cam only bolts on one way, And will only go in at tdc. Checked spark with on of those screw in/out plug to coil then ground tools. Was able to screw it out about 3/4 inch, got nice constant arc.

[Lukeatc185]

so you were getting arcs from the coil? did u ground your plug and check for spark? if your getting spark. you have decent compression. and your timing is good. it can only be fuel. only need compression, fuel and spark at the right time to fire. if your certain its timed right. troubleshoot from there. check to see if u have spark from the plug. if you do. and your at 120lbs of compression. rules out to be a fuel problem?

[FATTYFIVE]

Tried two plugs, both spark good, and thru spark tester. Comp. should be 175+/- 22lbs. Seems awful low to me @120. Is there any way for the timing to be out? All marks line up, Unless Im missing something. Tdc--mark on cam sprocket at 9 o'clock---cam olny bolts on one way---cdi only goes on one way. Am I missing something else. ------BTW comp. reading with a push-in type guage. NO INTAKE MANIFOLD, spinning motor at 900-1000 rpms with a Hilti screw gun.

[Lukeatc185]

with 120psi u should be able to get it running though. if its because of the low compression u should be able to bump start it. get some friends to push you then pop it into gear. if the compression is the problem it should start if u can get it turning over fast enough.

[Lukeatc185]

also are you checking compression while holding the throttle open? thats the correct way.

[FATTYFIVE]

I checked it with no manifold. Thats as Open as it gets.

[Lukeatc185]

does it hold the compression or does it leak out slowly?

[FATTYFIVE]

Thanks All, for the ideas, Going to put a new piston and topend in. Go from there. I dont want to "drag" start this every time. ATC'S are thetrailpro :beer