Excessive compression

[utopians]

Hi all
I rebuilt my Husqvarna 141 with aftermarket cylinder and piston. With plug out it turns over with no problem, but with plug in it has so much compression I can’t start it. I removed muffler but still same problem.
Any suggestions

 

[ballisticdoughnut]

Without actually looking at the parts you used, I’d say that’s probably normal. Anywhere from 150 to 170 psi is normal compression for most saws. They can be hard to pull over especially if you don’t have proper technique.

 

[Chevboy0167]

Try checking the squish... piston may be too close to the combustion chamber.

 

[The Shooters Apprentice]

Does it actually hit something, or do you just need to pull it harder? Have you checked the compression?

 

[Automender]

Make sure plug isn't hitting the top of the piston. Install it but don't tighten it so you get leakage but still inserted to the right depth

 

[Chevboy0167]

I have re-built many of these small 100 series Husky engines, but I re-used the original cylinder with Meteor pistons or found new old stock parts on eBay. Heck... I even got a used cylinder for a re-build 1 time. No problems. Hence why I suggested checking the squish with the aftermarket parts.

Good call on the plug idea also Automender.

 

[utopians]

Hi all
I rebuilt my Husqvarna 141 with aftermarket cylinder and piston. With plug out it turns over with no problem, but with plug in it has so much compression I can’t start it. I removed muffler but still same problem.
Any suggestions

 

[utopians]

I don't have a compression tester and at this point haven't done the squish test. i'm not even sure i can do it properly. However i did install the plug with just one turn and the rope pulled fairly easily. then with it 1/2 to 3/4 in the rope just about pulls out of my hand.
I know these engines have high compression but this is ridiculous. I'm looking into getting a compression tester today

 

[The Shooters Apprentice]

I don't have a compression tester and at this point haven't done the squish test. i'm not even sure i can do it properly. However i did install the plug with just one turn and the rope pulled fairly easily. then with it 1/2 to 3/4 in the rope just about pulls out of my hand.
I know these engines have high compression but this is ridiculous. I'm looking into getting a compression tester today

If you have a harbor freight near you they have a cheap one that works decent.

 

[Homer6679]

+1 on the Maddox kit from harbor freight, I use that shizz all the time lol