Gas gets pushed out of my fuel line, into the tank again

[Robert Derespina]

Ok, so I just bought an engine kit and put it together. Its my first one and the two times ive got it to run, it ran perfectly fine. But in between ive come to notice that after priming, the gas would kind of suction down my fuel line, and as soon as it hit the fuel filter, it would start getting pushed back into the gas tank, and idk how to fix it. This last time it started working after I took the screen filter off the fuel switch, but now it's just pushing the gas back into the tank, from the top of the fuel filter all the way back, faster than I can pedal the bike up to speed. What could be wrong and what would I do about this? Also, the gas in the filter and in the line going to the carb have gas in them, as does the carb, but trying to start the motor on just that, the bike will just automatically bog down and turn off

 

[crassius]

put the screen back on - what you are seeing is air bubbles rising out of the carb as fuel flows down and that is normal - just ride and enjoy

 

[Robert Derespina]

put the screen back on - what you are seeing is air bubbles rising out of the carb as fuel flows down and that is normal - just ride and enjoy

Ill try that, but it was happening even with the screen on. Its just filling the filter and carb with gas, then going back into the tank, and nothing will come out with the fuel switch set to on, or reserve. I have to over prime it or squeeze the gas line a few times to get gas to come into the line, and im sure thats why my engine has been bogging down and dying as soon as I pop the clutch

 

[crassius]

these things use very little gas - sometimes the line will look empty - the test for flow is to take drain screw out of carb bowl and watch how much comes out when gas is turned on

 

[Robert Derespina]

these things use very little gas - sometimes the line will look empty - the test for flow is to take drain screw out of carb bowl and watch how much comes out when gas is turned on

Runs like a mini faucet. Still trying to work on it tho, and cant figure out why the engine is bogging and dying as soon as I let the clutch out

 

[crassius]

you need to pedal a few times to get bike moving before letting out clutch when motor is running - these aren't powerful enough to pull from a dead stop

 

[Robert Derespina]

you need to pedal a few times to get bike moving before letting out clutch when motor is running - these aren't powerful enough to pull from a dead stop

Im going at least 7 miles an hour when I let out the clutch, and I continue to pedal and the bike starts to slow down and not let me pedal at all, idk what the problem could be with this since I got it to start a few times earlier and didnt touch anything after, except tightening the chain which came really loose. But now like I said, I let out the clutch and it revs up, throttle response is great, but the bike just slows down while im pedaling and it wont let me pedal after a few seconds, what could this be caused by? Am I supposed to pop it to start the engine and hold it in while pedaling and giving it gas? I didnt have to do that any of the other times I got it to start tho? Im so confused

 

[bakaneko]

I think others might say the same that there might be a leak somewhere. Check the carburetor and intake manifold connection and re-tighten. Also, the head bolts might have stretched since your first couple of rides so re-torque them in an X pattern paying careful attention to not over torquing and use multiple test rides if you do not have a torque wrench.

 

[crassius]

not sure what you mean by 'won't let you pedal', but I'm wondering if you have enough oil in your mix - for a new motor, 8oz per gallon is OK and well shaken before it goes in tank

 

[Robert Derespina]

not sure what you mean by 'won't let you pedal', but I'm wondering if you have enough oil in your mix - for a new motor, 8oz per gallon is OK and well shaken before it goes in tank

I had someone help me with the mix, its roughly 8.2 oz of oil in the gallon, but when I let the clutch out and try to keep pedaling, it progressively gets harder and harder till I cant turn the cranks and the bike shuts off