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Old 03-29-2013, 06:24 PM   #1
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Default Air bubbles in fuel line to carby!

Is this caused by an airleak in the pipe or an issue with the fuel tank? It only seems to do it as the fuel level drops down in the tank. I have tried different length pressure lines from the exhaust and it didn't seem to make any difference. I am thinking it is more the tank and am tempted to try a different tank and see what happens.

Thanks for assistance!
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Old 03-30-2013, 06:54 AM   #2
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If the bubbles only appear when the tank is below full it could be a hole in the fuel line / joint inside the tank.
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Old 03-31-2013, 01:03 AM   #3
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Originally Posted by El Nitro View Post
If the bubbles only appear when the tank is below full it could be a hole in the fuel line / joint inside the tank.
Thanks, Am going to try another fuel tank and see if that makes any difference.
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Old 04-01-2013, 05:31 AM   #4
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Well tried again today with a different fuel tank and still getting those annoying bubbles. I thing I have noticed is the fuel tank lid is very easy to open on the tank. Just as a test I pushed down on the lid after adding fuel and it ran fine no tune issue, came in and someone else added fuel for me and bingo straight away engine was off and after further inspection we had bubbles again
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Old 04-01-2013, 05:36 AM   #5
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The cause could be vibration, make sure your fuel tank sits on rubber rings or insulators and is mounted loosely on your radio tray.
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Old 04-01-2013, 11:37 PM   #6
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The cause could be vibration, make sure your fuel tank sits on rubber rings or insulators and is mounted loosely on your radio tray.
Michael:

Thank you, this is something i hadn't thought off... it sitting on alloy posts on the radio tray with a rubber gromet pushed through the hole in the tank. What i think makes it worse though is a plastic top hat sits over the top that the clip goes through holding it down... The tank as no play and i know some brand cars allow for the tank to have some movement in their design of radio tray.
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Old 04-11-2013, 10:28 PM   #7
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i had exactly the same issue with my OS TG the other week. it ended up being the spring on the exhast, the one around the engine. with it being too loose i was loosing almost all of my backpressure and inturn fuel wasnt being pushed through the fuel line, it was sucking air instead.
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Old 04-12-2013, 06:37 AM   #8
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Originally Posted by brendon.matt View Post
i had exactly the same issue with my OS TG the other week. it ended up being the spring on the exhast, the one around the engine. with it being too loose i was loosing almost all of my backpressure and inturn fuel wasnt being pushed through the fuel line, it was sucking air instead.
Thank you I will have a look at that, I have a feeling the exhaust is on a slight angle because I haven't got the exhaust wire quite right on the car.
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Old 04-18-2013, 05:19 PM   #9
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I was gonna post one like this. I have the same finding as Bundy Bear but that is not my ISSUE per se.
I tried to break in my engine today. Went through 1/3 gallon. Idle RPM is way too high at proper high speed needle. So I tried to close idle screw. I had to close it almost entirely to lower Idle RPM. There's air bubble in the fuel line between carb and tank. I also seem to notice the bubble only when the tank is below full.
The engine is new, the tank is new, the line is new. The only thing i can't trust among those is the tank because I got scammed to buy this car by a guy here with ID OneTrade.
Please advise.
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Old 04-21-2013, 08:29 AM   #10
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Bundy bear and I exchanged some info. We both checked fuel tank but it didn't help. I mounted the tank again thinking that the rubber grommets were not in correct place didn't make any difference. I'm not sure if it's the air bubble or my lack of tuning skill that gives me high RPM during idle. The carb should be almost completely closed to maintain low idle RPM. Same exact thing that I had before I sent the engine for service. I'm afraid that I break the engine again after spending another $176 to fix.
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Old 04-21-2013, 09:47 PM   #11
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I guess the air bubble doesn't matter much when it comes to tuning the car. I set my engine today real nice. Despite the bubbles, my car ran beautifully w/ only 200 degree temp and pretty decent top speed and low idle RPM.
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Old 04-26-2013, 07:51 PM   #12
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I think my issues where coming from the exhaust and it night quite being straight on the gaskets due to the wire mount.

I have moved the engine to a different car and used a brand new exhaust, but made sure everything was straight and mounted as good as I could get it and had no issues.

Something I have learnt is to install a rubber band on the carby ball end to pull it shut and bring the motor back to a correct idle every time. My current Os TG has a few on it to give it the strength to pull it shut as it seems to get stuck in its action some times.
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Old 05-07-2013, 01:39 AM   #13
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switchout the seals on the pipe and see if it helps
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