Scooter Doc
Currently Offline
Triangular Shaped Head!!
Posts: 437
Likes: 8
Joined: May 24, 2013 21:16:22 GMT -6
|
Post by FACE PLANT FOR LIFE on May 8, 2014 7:02:52 GMT -6
We got a Hyosung SF50 with low compression. It's a two stroke. Are there any simple things (like valves) that would cause low compression on these engines (120PSI)? I don't know the engine code/can't find it.
|
|
Doc's Anything Goes
Currently Offline
Say no to scooter abuse
Posts: 3,873
Likes: 156
Joined: Mar 31, 2010 19:07:16 GMT -6
|
Post by jct842 on May 8, 2014 20:10:24 GMT -6
rings or a leaking head gasket
|
|
Scooter Doc
Currently Offline
Posts: 274
Likes: 1
Joined: Aug 25, 2013 21:40:53 GMT -6
|
Post by mikey34 on May 24, 2014 21:24:05 GMT -6
Or a leaky crank seal, I've had a 66cc motorized bike do that, LOW comp.
|
|
Doc's Anything Goes
Currently Offline
Say no to scooter abuse
Posts: 3,873
Likes: 156
Joined: Mar 31, 2010 19:07:16 GMT -6
|
Post by jct842 on May 26, 2014 16:02:41 GMT -6
The crank seal won't cause loss of compression but it will cause the engine to have trouble getting a fresh charge of air/fuel from carb to on top of the piston. One other cause of loss of compression is a hole in the piston. I saw a rotax run out of gas at about 9000rpm and it put a hole in the piston. (went real lean and got real hot)
|
|
