ATC 70 jetting.

[TravEX]

On my 85 70, I can't get it lined out!

It starts 1st pull, idles great. Takes gas great till above 3/8 throttle.

Completely stock, all it has extra is open air filter (clamp on from Dr ATV).

I just rebuilt the carb, all new jets, went up to a 60 main jet from a 58 because of the open air filter. Pilot 1 1/4 turns out. Carb is clean, and NO air leaks (I checked).

When I'm riding it, it will pull good till 3/8 to 1/2 throttle, then just cuts out. When I let off it starts idling good again.

Could it be the points? Or do I need to go up another main size or 2?

When it had the stock air filter system on it, it would rev good. I had to go to the clamp on filter because the old air box boot was junk.

Thanks,

Travis

[TimSr]

Could it be the points? Or do I need to go up another main size or 2?


Its highly unlikely that its a carburetion adjustment that would make it that far out of whack for such a minor change. A carb "malfunction", such as a choke problem, maybe, but not an adjustment such as jetting.

Id definately be looking at the points first. Check point gap, and also check for wear, not so much on the contacts as the part of the points assembly that rides the flywheel to make them open and close. As this wears, the points open more and more, and ignition timing is retarded more and more, causing symtoms like you are experiencing. If it is worn, point gap can be re-adjusted closer and improve the situation, but the timing issues can only be compensated for so much, and teh poinst really need to be replaced. Condensor should be replaced at the same time.

[TravEX]

Thanks alot for the info. I'll check into that!

Travis