View Single Post
Old 08-03-2010, 01:57 PM
GearNut's Avatar
GearNut GearNut is offline
Motorized Bicycle Elite Member
Join Date: Aug 2009
Location: San Diego, Kaliforgnia
Posts: 5,106
Default Re: Help.. Broken Bottom engine casing.

What color is the spark plug?
Always let the engine cool down completely before removing the spark plug or you risk the threads coming out of the cylinder head.
The color will show you approximately what the air/ fuel ratio is.
Black = too rich.
Chocolate brown = perfect.
White or light brown = too lean.
Silver = damage to piston and waaaaay too lean.
The downhill only part is kinda wierd. I want to say it may be chain tension related.
"It's a chinagirl. It's a sometimes fun little engine that often will break your heart. It's disposable.

Does not come with a fortune cookie."
Reply With Quote