262XP Questions

[weekwarrior]

So I asked a question about my 262xp a while back about getting it ported. Decided to keep it in stock form. It just wasn’t running real good. It would be great then take a notion to not idle and be hard to start. Pulled out the compression gauge and it was a little under 100PSI. Decided that it was probably the root cause of the issue and so that got me on the move! Decided to order a complete top end kit as well as a carb rebuild kit. Installed everything today. Fired right up. Dialed in The card and ran and sounded great. Decided to pull the plug and check the compression and it was the same as before if not a little less. I noticed right off the base gasket was really thick and even questioned leaving it off. But with no solder I leaned on the side of caution and installed the gasket. I mainly ordered the cylinder with the piston and ring as to make sure I had everything ready so I could tear it down and put it right back together. The stock cylinder was in great shape for a 20 yr old saw. I put up and will send it off for porting very soon. I’m looking for advice on if any of you wizards have experienced anything like this before. All ideas and comments are welcome. I double checked all my work and and confident I have everything installed correctly. In stock form with base gasket installed….what should the compression be??

 

[ballisticdoughnut]

Never had a 262 but generally speaking most chainsaws will be somewhere between 150 and 180 psi for compression after they’re broken in. 100 psi is very low, to the point the saw would be nearly unusable. Are you using a proper compression tester for small engines?

 

[weekwarrior]

I ordered my compression gauge from Amazon and have no idea if it was rated for chainsaws or just regular motors. Would have never thought there could be a difference. I have rebuilt several saws and have had good luck. This site has been amazing with all the knowledge and help! If you have a link for one that’s rated for saws that would be really helpful

 

[weekwarrior]

This is the one I have.

https://www.amazon.com/JIFETOR-Comp...ion+tester+for+chainsaw&qid=1668390284&sr=8-3

 

[Bob Hedgecutter]

If you have other saws- compression test those and see if you come up with similar low numbers on a known strong running saw.
Odds are good your tester is designed for larger capacity cylinders and the Schrader valve is too strong and probably at the wrong end of the supply tube.

 

[weekwarrior]

Funny you say that. I pulled the plug out of my 357xp that’s WP’d base gasket delete. Timing advance and MM’d. Compression came up on it at 115 and it’s a beast of a 50cc saw.

 

[Chevboy0167]

Also, a vacuum and pressure test of the bottom end would be advised. May find a crank seal or seals leaking or a possible crankcase gasket leak.

 

[2StrokeFondler]

This is the one I have.

https://www.amazon.com/JIFETOR-Comp...ion+tester+for+chainsaw&qid=1668390284&sr=8-3

Does it have a valve in the hose? Like this one does: https://www.amazon.com/Bosch-FIX-78...id=1668518991&sprefix=FIX+7828,aps,654&sr=8-1 ? If not, it's probably not suited for such small engines like a chainsaw.
I second the purchase of a vacuum and pressure tester. I got a cheap generic one from Amazon, and I'm happy with it. It's really nice to be SURE I don't have a leak.