Metallichg
ArboristSite Operative
Could somebody please explain compression in terms of my situation:
I bought a Stihl 070 with a 090 cover, sold as an 090. I checked the compression of the 070 and got 50 PSI when pulled over many times without using compression release. it turned over easy. I changed out the PC and clutch on this saw using an expensive Mahle 090 PC. after putting it all back together, I checked compression again. I barely had enough muscle to turn the saw over. I pulled the starter 5 times and was only strong enough to get one compression stroke each pull. my compression Reading was 100PSI. Is this good or bad? I have read posts from people that are getting 185 PSI on their saw. How is that possible? I may be a 6'1" whimp, but I can't possibly be that weak. What am I not understanding about compression that would make this make sense? I fired up my saw with new clutch and PC. I thought it ran great. Definitely needed compression release to start, but started up from zero gas in about 3 pulls. Was kind of poppy when idling and had tons of muscle with a 36" bar, 404 chain, 8 pin sprocket and some big maple, ran about 3 tanks of gas (in about 30 min). Can somebody please give me some info to explain it what am describing regarding compression, and does this sound normal for a 090 with new PC? Since I don't know, I would rather ask the experts than make guesses on my own. thanks very much-Joe
I bought a Stihl 070 with a 090 cover, sold as an 090. I checked the compression of the 070 and got 50 PSI when pulled over many times without using compression release. it turned over easy. I changed out the PC and clutch on this saw using an expensive Mahle 090 PC. after putting it all back together, I checked compression again. I barely had enough muscle to turn the saw over. I pulled the starter 5 times and was only strong enough to get one compression stroke each pull. my compression Reading was 100PSI. Is this good or bad? I have read posts from people that are getting 185 PSI on their saw. How is that possible? I may be a 6'1" whimp, but I can't possibly be that weak. What am I not understanding about compression that would make this make sense? I fired up my saw with new clutch and PC. I thought it ran great. Definitely needed compression release to start, but started up from zero gas in about 3 pulls. Was kind of poppy when idling and had tons of muscle with a 36" bar, 404 chain, 8 pin sprocket and some big maple, ran about 3 tanks of gas (in about 30 min). Can somebody please give me some info to explain it what am describing regarding compression, and does this sound normal for a 090 with new PC? Since I don't know, I would rather ask the experts than make guesses on my own. thanks very much-Joe