engine makes popping sound

[cordy]

Yes there is look in front of ur primer bulb,still cant see it,go to ddm look up part # av493 team chase carb diaphram. This is your breather for your carb some times dirt gets in there and causes problems. The hole in the gas cap is not big enough go to ur hobby shop and get a 8/32 fuel nippli,drill the aproriate size hole in the gas cap and thread in the nipple. Then take a piece of fuel tubing and run it up then down and out secure with zip ties . Here is a picture of my xb witha gas cap vent.

 

[Erik J.]

I have a nippl that has an hole in it of 2.5 mm.is that good or do i need a bigger hole for venting the gas cap.

 

[Deluge]

2.5mm is good.