Intake leak?

[tbgeorge]

Hi, I recently bought a 2 cycle 80cc motor kit and installed it on my bike, but now when I try to ride, when I pull the clutch in the engine rpm's go sky high!

Someone told me that it was an intake leak and to: "Remove the intake manifold where you bolted it to the engine, and replace the gasket with another." I'm a little confused where that is. Can someone please help me out?

I also had to solder some copper pipe to the pipe that connects the carburetor to make it fit outside of the bike frame. Could that be the cause of the supposed leak?

 

[Dave31]

The intake gasket is between the Jug and intake. Once you remove the intake you will see the gasket.

I'd spray some wd-40 or water around your intake and carb and a change in rpm will indicate where you have a vacuum leak.

 

[Al.Fisherman]

I also had to solder some copper pipe to the pipe that connects the carburetor to make it fit outside of the bike frame. Could that be the cause of the supposed leak?

Ummmm since most intake manifolds (supplied in the kit) are made of aluminum, and not steel (but they can be bought), is your intake aluminum? If so, how did you solder the copper to it.

 

[MotorBicycleRacing]

Hi, I recently bought a 2 cycle 80cc motor kit and installed it on my bike, but now when I try to ride, when I pull the clutch in the engine rpm's go sky high!

Someone told me that it was an intake leak and to: "Remove the intake manifold where you bolted it to the engine, and replace the gasket with another." I'm a little confused where that is. Can someone please help me out?

I also had to solder some copper pipe to the pipe that connects the carburetor to make it fit outside of the bike frame. Could that be the cause of the supposed leak?

How did you seal the copper pipe to the carb?
That is probably where your leak is.

Does your carb slide over the copper pipe?
you can put an O ring in the carb to seal against
the pipe or use some kind of goop.

Ummmm since most intake manifolds (supplied in the kit) are made of aluminum, and not steel (but they can be bought), is your intake aluminum? If so, how did you solder the copper to it.

Ummmmm, A lot of the kits come with the steel intake.

 

[tbgeorge]

Ummmm since most intake manifolds (supplied in the kit) are made of aluminum, and not steel (but they can be bought), is your intake aluminum? If so, how did you solder the copper to it.

I used electrical solder and some flux. I think the intake is aluminum, not for sure though, and I used some rubberized tape to tighten the carb around the copper pipe.

 

[MotorBicycleRacing]

I used electrical solder and some flux. I think the intake is aluminum, not for sure though, and I used some rubberized tape to tighten the carb around the copper pipe.

There is your leak or at the least one of them.

 

[tbgeorge]

There is your leak or at the least one of them.

Yeah, I realized that. I think I got it fixed, I reconnected the carb with a new gasket that I made and some heavy duty pipe wrap.

 

[remichi]

I have the same problem that as soon as I disengage the clutch the revs go up a lot.

One problem I has was that the 4 connector pieces (very very bad design by the Chinese by the way!) broke of the carburetor and I had to come up with a self welded solution. The bike does run with it but I think that might be where my problem is.

How do all of you fix the carburetor to the manifold without breaking the flimsy connectors? And is there anyway to make the carburetor/manifold connector more airtight?

Will try to post some pics of my carburetor soon.

 

[remichi]

Here some pictures of my carb:http://www.flickr.com/photos/michisunited/7759542500/in/photostream/

http://www.flickr.com/photos/michisunited/7759539564/in/photostream

http://www.flickr.com/photos/michisunited/7759540912/in/photostream/

Will try to make myself a soda can air filter, seems worth the shot. See the other motorized bicycle forum post:
http://www.motoredbikes.com/showthread.php?4314-nothing-fancy-homemade-air-cleaner/page2

Will also try some gas resistant sealer, hope that fixes my carb/manifold connection.