1983 atc 200 rebuild issue

[83atc200]

I just put the top end back together on my 1983 atc 200.. I put in a new cam chain, glides, and cleaned the piston. I lined up the ignition timing with the correct marks, put tension on the cam chain, put it all back together.. Now it will start up and run fine but it takes about a half an hour to warm up before it stops backfiring and running like crap.. But once it gets warmed up it will run fine.. I tried all adjustments on the ignition timing to the right and left, made sure everything is tight with no compression leaks, and was wondering if n e one had ne suggestions, I just don't know what could be wrong. open to any suggestions..

[sp8twn]

Did you line up the timing chain corecly sound like it might be off a tooth?:wondering

[oldskool83]

clean carb and make sure everythings free lowing. 1st add an inline fuel filter in case you have rust getting into tank causing this cant help. they typical 4bucks at a auto parts store or lawn tractor section of a hardware store.

[83atc200]

Did you line up the timing chain corecly sound like it might be off a tooth?:wondering

I noticed a mark on the cam gear, but not on the cam chain, is there normally a mark on the chain to line up with the mark on the sprocket?

[barnett468]

I noticed a mark on the cam gear, but not on the cam chain, is there normally a mark on the chain to line up with the mark on the sprocket?no. did you line up the t in the timing window when lining up the cam marks?

the fact that you say it runs fine suggests your cam timimng AND valve setting is ok and the poor initial running is therefore a mystery to me.


All i can suggest at this point is cxcheck the plug color and let us know what it is

was it a new plug?

is it the correct factory heat range?

a cold plug can contribute to this comndition.

what is your air temp there?

is this the same carb you ran before?

any burble or hesitation upon acceleration?

At least it eventually runs good and not worse, lol.

[barnett468]

how old is your gas?

[83atc200]

how old is your gas?


I lined up the t in the window with the ignition timing marks that slide on to the cam if that's what you mean?? Everything else you mentioned seems fine, and the plug is black in color but looks pretty normal to me..

[83atc200]

how old is your gas?

And there is a hesitation upon acceleration, that's when it seems to back fire..

[83atc200]

I think trailprotrailpro right, it runs way to good to be a timing issue, but its just funny that it didn't give me this trouble trailprotrailpro..