Compression

[AKDriveSprocket]

New member and first post. I have a husqvarna 350 that only reads 100lb when I do a test. The saw is 7yrs old but runs good. Will just installing a new ring improve the compression on it.

 

[Bowtie]

That depends on what the piston and cylinder condition are. Posting a few detailed pics would help a lot.

 

[computeruser]

Are you using a pressure tester that is appropriate for a small engine?

 

[Lakeside53]

New member and first post. I have a husqvarna 350 that only reads 100lb when I do a test. The saw is 7yrs old but runs good. Will just installing a new ring improve the compression on it.

If it's only 100.... it will be real dificult to start, and run like a pig.. if it isn't ("runs good"), then look at your compression tester...

 

[Poley4]

Are you using a pressure tester that is appropriate for a small engine?

Huh, I didn't know they made such an animal. How are they different then one made for automotive use?

 

[Lakeside53]

Huh, I didn't know they made such an animal. How are they different then one made for automotive use?

Schrader valve at the tip.... many "car" testers don't have one as a few cc in the hose doesn't make any difference.

 

[Poley4]

Schrader valve at the tip.... many "car" testers don't have one as a few cc in the hose doesn't make any difference.

Makes sense. Thanks!

 

[AKDriveSprocket]

My gauges must be off. I tried two of them both on the same hose with a schrader valve on it just to see, but it was just acouple LB off between the two gauges. The saw runs great. I have not taken the saw apart yet to take any pics.

 

[Lakeside53]

If it runs great, cut wood...

 

[Poley4]

Like they say,"if it ain't broke, don't fix it". The piston in my 036 is visibly scored when viewed thru the exhaust port, but it runs so strong, I'm going to leave it alone.

 

[Bowtie]

Like they say,"if it ain't broke, don't fix it". The piston in my 036 is visibly scored when viewed thru the exhaust port, but it runs so strong, I'm going to leave it alone.

my 034 shows scoring as well. But it runs good, and Im turning it into a 036 when it dies, so thats my plan.

 

[rxe]

I've got a question on compression testing. I use an automotive tester, and when I pull on the cord, the first compression stoke produces about 90 PSI on the dial, but by the end of the cord, I'm up at (say) 150.

I'm guessing that the final reading is the correct one...and that the saw is just struggling to pressurize a tester designed for a car engine.

Is this correct?

 

[Poley4]

my 034 shows scoring as well. But it runs good, and Im turning it into a 036 when it dies, so thats my plan.

Sounds like a good plan to me, awesome saws!