Yamaha G5 maybe backfiring out intake

[brinkkl2000]

I am not 100% sure on the model, the plate is gone, but I think it is a g2, 5, 8,9 something in that era. It will run smooth at a low throttle but as soon as I give it gas it will start popping through the intake. It has a new carb, new intake, new plug, I adjusted the valves and they seem to be moving fine. The cart runs great with the choke out, which I am thinking means it is running lean. I sprayed around the intake when it was running looking for air leaks and didn't find anything. Is there anything else I can check? The old plug was pretty black and sooty. The air filter is new too, the lid for box may be a little warped, but even if I hold it down nice and tight I get the same results.

[Spicyunicorn]

Air box has to be completely sealed iv had good lucking sealing warped air box lids with wrapping gorilla tape around the lid and air box

[brinkkl2000]

So, these engines really are that sensitive to air flow? If I can't get it sealed up well enough, could I jet up to compensate for the increased air or wouldn't that be a viable option.

[BrutalSoldier]

Ya very sensitive to air leaks. Better to try and get good seal.

[brinkkl2000]

Thank you for the tips. It worked perfectly... so far. Pulled the air box out and taped it up good with Gorilla tape and no more popping, engine runs fine.

Next problem, maybe will start a new thread. The secondary clutch is shot, the buttons are gone and the ramps on the sliding sheave are worn out, I got everything apart and new parts coming, but I noticed the different settings (holes) on the different parts for the clutch spring. I now what holes the spring came out of on each piece, but don't now where the sheave was in relation to the ramp. How do I figure this out. Hope that makes sense