Power Fade and profuse gas leaking

sn0wy

New Member
I have a 66cc kit pretty much stock aside from SBP pipe, 40tooh hub, ngk ignition parts, and the carb is leaned out one notch. I am running a goped gas tank with a goped sized fuel line down to the carb. I have two problems that I think may be associated with each other-

-Fuel profusely leaks from the carburetor during and after every ride, all seals are tight, the bike sits straight up, fuel switch off position.

-When winding up the bike I get about 10-20 seconds of good clean top end at about 35 mph, then it bogs out for a bit and drops down to about 3/4 speed/rpm. It's very annoying and can be dangerous when I'm riding with traffic. My carb is leaned out one notch, I have to slightly unscrew the goped gas tank to get fuel to flow, and my lines are slightly narrower than the stock lines. Could this power fade have anything to do with my setup?
 
Sounds a lot like a float level problem. Peice of debree can get into the needle valve seat. Or the float bowl level may need adjusting. The thought of the petcock truly being turned off comes to question? Might double check its operation with the fuel line pulled from carb draining to a cup.

Here is a link to the carbs taken apart and explained. Hope that helps things.
http://motorbicycling.com/f4/motorized-bicycle-carburetor-pictures-how-install-195.html
 
Tighten all the screws & fittings on the carb to fix the leak.
A normal size fuel line can't hurt.
Try running it with the needle clip in the top position. (leanest)
 
-Fuel profusely leaks from the carburetor during and after every ride,
That is your problem right there, if your carb bowl is over flowing your motor
will never run right. Forget about adjusting anything until you get the flooding fixed.

There have been a lot of these problems lately....
 
I would look at the float to see if it has a crack/leak in it and is not shutting off the needle valve properly or there might be some trash in the valve that is not allowing it to close. What inside diameter is the fuel line you're using? Are you using an in-line filter?
Also find out why the fuel tank cap is not venting. You should not have to loosen it to get flow. Get this flooding/flow problem corrected then see how your engine runs. Let us know what you find.
Tom
 
gas leaking, Same problem /solution

I had the same problem and I did three things First: I made a new gasket for my carburetor manifold.

Second: I took out the two screws that held my carb bole in place and bent down the fingers that touch the float by about a quarter inch.

Finally I got some gasket sealer and coated both the top of the carb and the bowl where the gasket sits a then waited for them to set up. I then put the thing back together and went for a ride.

I know have plenty of power and no leaks. even when I left the the gas tank valve open when I went to the store.

Mike
 
I also got a carb gasket before from S.B.P. that goes between the carb and the manifold(its a round flat gasket not a o-ring)
 
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