illmatic94

iTrader: (12)

hey guys, i recently bought a novarossi .12 flash engine for my xray nt1. during my 4th ish tank in break in i noticed the engine would act erratic after it finally warmed up. i found that there were air bubbles in the fuel line. now i changed the fuel tank, fuel lines, glow plugs and inspected the engine for any visible problems. after non of that worked i tried to manage and finish breaking it in. during one of the runs i noticed the air bubbles would pop out of the carb into the fuel line, then get sucked back in causing the engine to act crazy lean and even cut out sometimes. if anyone knows why this could be happening it would be aprricated . im running odonalds 20% race fuel and i believe a"hot" glow plug

Bundy_Bear

iTrader: (11)

Check the grommets that the tank sits on and make sure the tank isn't too tight. I have bubbles in the fuel lines on my 2014 but hasn't effected engine performance.

illmatic94

iTrader: (12)

I checked that a while back even changed the fuel tank.

illmatic94

iTrader: (12)

I'm thinking of just buying a used motor

Bundy_Bear

iTrader: (11)

Otherwise check carby is tight and HSN is down tight.

illmatic94

iTrader: (12)

You mean where the hsn and the fuel intel screws into carb?

illmatic94

iTrader: (12)

Could this be from bad fuel?

Bundy_Bear

iTrader: (11)

No from adjusting when installing engine and it will create an air leak.

illmatic94

iTrader: (12)

I will checj it out, it only happens when the engine finally warms up,the tube will be perfect but once the air bubbles pop up all hell breaks loosr

Geezatec

Seal the fuel line from tank to carb. You can seal around banjo fitting and inlet to carb housing. Cushion the tank with 'O'-rings. And tune the engine. Small bubbles will dissipate.

spooky 1

iTrader: (1)

If it only does this after the engine is warm, you may be a bit lean on your needles.

illmatic94

iTrader: (12)

I figured that but the majority of the run the engine is turned properly but it will act erratic and Leann for about 30 seconds or so , then back to normal. That's if it doesn't cut out from no fuel

Geezatec

A large bubble? or small bubbles like fish eggs? What width the Throttle air gap?

illmatic94

iTrader: (12)

Tiny tiny tiny bubbles, almost like dots. There could be like 100 in half the fuel line. And tbh I don't know, it may be to large. Could that cause the bubbles

Geezatec

Did you seal the fuel line, tank to carb? This line should be the shortest as possible. Have to know the air gap of throttle. Small bubbles may be easy by leaning or richening. There is only one way air is being formed, if fuel line is sealed. Maybe you can answer it yourself!! Can you guess???