Help: Fuel Leak

[Ron-P]

I'm new to motor-bicycling and these engines so I'm not sure if small leaks
are normal or not. I bought the bike with 36 miles on it. The owner had
a mixture of 20:1, I drained it and put in 30:1. I've notice an increase
in the leaking, but not 100% sure if it's due to the change in fuel/oil
mixture as I'm riding it much more since I've changed the fuel.

My best guess is the leak is coming from the air intake. I took off the
air filter and it had some fuel on it and a small puddle at the base
of the air filter housing. I cleaned and dried it and rode the bike for
a mile. I check and there's a small amount of fuel puddled again,
behind the air filter.

It seems to be dripping from behind the air filer, down the bikes seat
shaft and dripping on the base of the bike where the kick-stand is
mounted.

It's marked by the purple boxes in the pics below.

Also, in the top pic, to the upper left corner of the purple box there is a small
screw with a spring, can someone tell me what that does?



Happy Motoring!

 

[georgeknight]

Might check to see if your float is too high. I had to lower mine when I first got my bike together. The button with the spring is a primer. I never use mine my bike starts up without having to use it.
Hope this helps...........George

 

[Ghost0]

That is actually pretty common. It is most likely blowback from your intake. Since these engines don't have a reed valve the intake is open until the piston closes it. It will tend to blowback some of your intake charge. Once you break the engine in and running less oil it won't be as apparent. You may also be running a bit rich. After break in, get a new plug and check your mixture. You may want to go a little leaner, lower your needle by raising the e clip.

 

[Ron-P]

Thanks guys, but, I'm not sure what / or how to, adjust the float or lowering the needle and raising the e clip. Any chance you could point me in the direction of how to adjust these?

Is there any where I could locate an instruction manual / assembly manual for these engines that might help me get familiar with them.



Happy Motoring!

 

[Ron-P]

Awesome, thanks seca40.

 

[Norman]

the classic posts will help it has pictures and other goodies there I know I did some of it.
Norman

 

[stude13]

you did a very nice job of illustrations. i noticed the cap nuts, toss those shown and the others too, replace with good nuts and lock washers and blue locktite.

 

[Ron-P]

I will, thanks for the tip.

 

[Dave31]

Running out of time here...Use these pics along with Secca post to help U out

 

[Ron-P]

Before doing anything to the engine I switched back to a 20:1 mixture and the fuel leak all but stopped, it's almost non-existent. Seems the more oil in the fuel is the cause for the heavier leak.

 

[toytime]

No, I'd say that while the gas evaporates, the extra oil stays behind. I think you get my point.