05-SE-SHEE Posted April 30, 2014 Report Share Posted April 30, 2014 Hey guys, I'm pretty new to this 2 stroke stuff so bear with me. I've been reading my eyes out and cant find anything related so I thought I would ask here. I got a new to me shee and when I test rode it, it ran like a scalded cat. The more I got to know it I noticed it spitting water after it was warm so I did a compression test on it. It was 155 both cylinders so I figured it had 21cc domes in it. (more on that later) It has a modquad head, so I ordered an o-ring kit and pulled the head off. It was obvious that whoever put it on didn't have a clue wth they were doing as there was siclicone everywhere. The left hand cylinder had obviously been leaking coolant down inside the exhaust port and it looked a little shiny near where the exhaust first leaves the cylinder. There was no visible pitting in the piston or domes and the walls looked as if there wasnt much wear on it. No little ridge near the top of the cylinder where the rings stop moving up. Here's the later part. It had 19cc domes in it and after some research looks like it should be closer to 180 lbs compression, so after I put it all back together I re-checked the comp and got 165 on one side and 172 on the other. 7 lbs difference anything to worry about? I have no idea how long it had been leaking coolant but figure it has been quite awhile. Is this anything to worry about?? I wondered if it could be about ready to let go so I pulled the exhaust pipe and looked up at the piston skirt to see if there were any brown streaks and it looks brand new. Opinions / suggestions gladly accepted. Quote Link to comment Share on other sites More sharing options...
Nieskes Posted April 30, 2014 Report Share Posted April 30, 2014 Whats your elevation? Compression seems to be at a normal amount if the motor is stock with 19cc domes. Quote Link to comment Share on other sites More sharing options...
Phelps Posted April 30, 2014 Report Share Posted April 30, 2014 165/172 gap wouldn't worry me that much, but i would be running at least 93 octane in it at that range. 160 is about as far as i would go on pump gas. some even say 150. 180-200 is racegas/alky range Quote Link to comment Share on other sites More sharing options...
05-SE-SHEE Posted April 30, 2014 Author Report Share Posted April 30, 2014 I am at 300 foot elevation. I don't want to run race gas even though I love the smell of it.... I'm going to get some 21cc domes. I know I could probably get by with 20's without race gas. Some guys I've read even run 19's without race gas. I was more worried about ring damage due to the coolant leaking into the cylinder, I'm pretty sure some was going into the cylinder as well as the exhaust as there was some coolant droplets on the dome when I pulled it off. I never noticed any pinging. Quote Link to comment Share on other sites More sharing options...
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