Sport moped exhaust on 66cc (Build thread)

[Vikingimike01]

http://sickbikeparts.com/bottom-bracket-cartridge-131-5mm-complete/

Thank you, I fixed that issue by welding a 10cm metal pipe to the pedal, maybe I should have posted that. My main problem now is the jetting. I will most likely need an electric starter to start my bike at any time, can't be pedal started, because my shimano shifter whatever doesn't spin the chain when the bike is rolling, so can't build up momentum to start it.

 

[Vikingimike01]

I possibly found the problem, theres an air leak somewhere. Just need to figure out where. I don't have the magneto cover on, could it leak there??

 

[gary55]

Use carburetor cleaner. With engine running spray around intake connections and crank seals. When engine changes rpm you have found your leak. For a idea of how it will sound spray a small shot at the air cleaner. Don't spray too long. As soon as you hear the change stop. The only way it could leak due to the absence of the mag cover is if the crank seal behind the mag is compromised.

 

[Vikingimike01]

Yeah, I know about how to do it, except I wet my finger with water and rubbed it around the seals when the engine was running. I don't have carb cleaner, but I guess WD40 or something like that would work. I'll do that.

I have a suspicion its the head or bottom gasket though. I'll keep an eye on that. Also I have reeds. Not sure if that matters, probably not.
An other thing, as the engine is hot the oil in the crank case evaporates and comes steaming out the exhaust and carb. Not sure if thats OK...

 

[gary55]

Sounds awful. I wouldn't run it for long before finding the leak. Good luck.

 

[Vikingimike01]

The only time I ran it for is trying to find the leak and trying to adjust it. Speaking about the leak, I found it. It's at the clutch cover. Probably a seal. I'm missing the gasket on that side. I put red RTV gasket on the outside, smeared it in the hole (There was like a 1mm gap between the case and the cover) and then put a thick-ish layer over it as well. Hope it will work! I'll check it out tomorrow, it should dry and solidify by then.

 

[Chainlube]

Yeah, I know about how to do it, except I wet my finger with water and rubbed it around the seals when the engine was running. I don't have carb cleaner, but I guess WD40 or something like that would work. I'll do that.

I have a suspicion its the head or bottom gasket though. I'll keep an eye on that. Also I have reeds. Not sure if that matters, probably not.
An other thing, as the engine is hot the oil in the crank case evaporates and comes steaming out the exhaust and carb. Not sure if thats OK...

I thought you had a 2 stroke, why is there oil in the crank case?

 

[Vikingimike01]

Because you mix the oil into the fuel and theres a little bit left all the time on the surfaces, thats what oils bearings and such, if it gets hot, it probably evaporates. I think thats what that thick smoke thing comming out of my exhaust OR intake for a minute after stopping the engine.

 

[Chainlube]

The crank and cylinder should only get residual lubrication, what is your fuel/oil mix?

 

[Vikingimike01]

I use a "heavy" ish oil mix, 25:1