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Post by therellik on Nov 24, 2018 14:38:24 GMT -5
About 2 months ago my brothers 49cc VIP Future champion started leaking gas thru the exhaust. I googled and it said the rings may be bad. So I have started the rebuild today. When I pulled the cam out it looked nearly new no lines no flat spots no nothing. Pulled the head off and noticed this was an 80cc BBK. The rings don't seem flat or broken. The piston is a little bit of carbon build up but its not bad. The rings on the BBK piston don't look bad either. Could the EGR system have conked out? I did smell fuel in the braded hose for it. Pictures posted soon.
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Post by jackrides on Nov 24, 2018 14:52:22 GMT -5
Leaking liquid gas out the exhaust is an overflowing carb.
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Post by therellik on Nov 24, 2018 22:18:28 GMT -5
I have the carb that was on it on my scooter with no problems of overflowing. Same gas tank with a high flow fuel filter.
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Post by GrumpyUnk on Nov 27, 2018 10:38:45 GMT -5
I do not see how liquid gasoline could leak from the exhaust pipe unless it was via some sort of EGR system or PAIR system connection. Fuel flows into the float bowl on the bottom of the carburetor. If the float valve fails, most likely(not always) fuel flows out the intake side of the carburetor into the air cleaner chamber and then to the ground. It could flow the other way into the intake port depending on the resting angle of the scooter. It could fill the cylinder if the intake valve was open or leaky. It could then work its way past the piston rings(through the end gap) into the oil sump. From there, it could fill completely, and come out the vent tube on the cam/follower cover. Maybe if full enough, flow through one of the vacuum ports on the intake elbow, but to where I could not say as they are all different in their plumbing. If the engine was running, it is possible that condensation from the exhaust gas could be coming out the tailpipe in liquid form, but that is water, not liquid fuel. Given the uptilt of the exhaust systems on most, it would take a lot of liquid in the exhaust to rise to the level of the exit port from the muffler. Quarts, even. Were I you, I'd get a set of head/cylinder gaskets, lap the valves, put it back together and adjust the valves. See how it runs after that. The piston rings should expand to be larger than the cylinder bore when at rest. If they do not, they may have lost their tension, and will not seal well, providing low compression and difficult starting. tom
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Post by therellik on Nov 27, 2018 14:08:58 GMT -5
That's what I was thinking. So im going to do away with the PAIR/EGR head and go from there.
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Post by SMALL CC TEK on Nov 27, 2018 22:51:10 GMT -5
Dude you just pulled it apart for fun ! lol A float adjustment or needle and seat and a oil change and plug you could have been back on the road ..
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Post by therellik on Dec 5, 2018 20:10:28 GMT -5
its not the float I have the carb that was on the scooter im fixing on my scooter and im not having a problem with overfill on the bowl. I believe its the EGR head. Changing it and leaving the BBK in it.
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