346xp early model squish problems

[Wornkknobby3]

So normally it’s arpund 18 thousandths from the factory? Well with no gasket that is?
I know once I crush the solder once the piston then moves up and down freely after the initial crushing of the solder.

 

[Andyshine77]

I find harder solder with the thicker gauge doesn't fully collapse unless you pull the saw over real fast, but I don't like doing that. Yes often times less than .018" in fact my 346 has .017" of clearance and it runs awesome. That's getting a bit tight thought, but I've run saws a long time like that, have a ported 7900 with less squish. All depends on the saws displacement and design.

 

[Wornkknobby3]

Ok so what your saying is your 346 is .017 running with no gasket?
Which in theory would mean I should be close to that.

 

[cuinrearview]

1/4" impact on the flywheel nut or clutch is nice for checking squish

 

[Andyshine77]

Ok so what your saying is your 346 is .017 running with no gasket?
Which in theory would mean I should be close to that.

Correct.

 

[Wornkknobby3]

Sounds good I’ll take a second measurement with a new piece of solder. So by having yours around .017 without a gasket do you run a thinner gasket than stock or just no gasket at all? As there are variable numbers I see as far as a “safe” .020-.016” squish allowance.

 

[Andyshine77]

I'm running no gasket. .016" is as tight as I'd want to go.

 

[Wornkknobby3]

So at that toalrance how many hours have you logged on? Just curious on longevity over stock form. This is my spare 346xp so I can at least test different scenarios out and not be put completely on a saw.

 

[Wornkknobby3]

I also am going to look for a different solder. The smallest reading I can get is .025”. I just tried it in all directions in the head and I can not make it anything thinner than that.
I can see in with a flashlight light that I’m right agains the cylinder wall when I have the solder in there.

 

[Andyshine77]

Yeah the solder has to be right against the cylinder wall. You always want to go with the smallest reading.

Don't know exactly how many hours I have on my 346 but that it's a well used saw, which is rare for me because of how many I own and how little I cut these days, it's my go too saw. I don't see anything abnormal on the top of the piston the saw behaves flawlessly.

 

[Wornkknobby3]

Sounds good. Maybe I can try putting the solder inside and then pulling the cylinder off to measure to see if that will give me a more exact tighter reading. At the moment I just stick it through the plug hold against the cylinder and cycle it a few times.
It does cycle freely after the solder is crushed without they piston touching once I crush the solder to the .025”.

 

[Andyshine77]

Sounds like .025" it is, again just make sure the reading is from the vary vary tip.[emoji111]

 

[Wornkknobby3]

So I finally have this saw all back together, originally put the new top end and deleted the base gasket, then found to have an air leak once running. Culprit was the smallest pin hole in the rubber boot imaginable. Could not even see it from the inside out.
Swapped it from a parts 357xp I had and all back together she runs mint. Compression with new top end and base gasket gone feels good, measured 150 hot just now. Fires on 1 pull warm and I’m very happy to have her back again. Running her alittle on the rich side for now to break it in.
Very glad to have such great info available on this site.