372xp issues

[slambox28]

 

[slambox28]

THis bearing is super crisp, only side wobble but no play from forward and backward forces at all!? The crank turns level and true. No kind of side load wobble from the crank bearing at all!

 

[Woodwackr]

add the OE base gasket you removed and it will be fine. and, that BASE gasket, not case gasket... ie, the one between the case deck and the cylinder.

 

[slambox28]

New gasket clamped down with the new jug

 

[slambox28]

add the OE base gasket you removed and it will be fine. and, that BASE gasket, not case gasket... ie, the one between the case deck and the cylinder.

the new gasket is non-OE, not sure what brand it is.

 

[slambox28]

Oh here is the original cylinder

 

[slambox28]

 

[slambox28]

Old piston

 

[slambox28]

The old and new both have the exact same behaviors, but no visible marking/indention on the old piston? my guess is that possibly it's hardened overtime from heat/cooling? but idk that doesn't seem like a realistic reason why, just can't think of any others

 

[slambox28]

New finding: the old cyl is a 50mm. This is the old piston inside the 52mm bore cyl!
2mm difference+/- I didn't know this until now.

 

[slambox28]

Another new finding: the ring thicknesses are actually the same for both pistons. This picture shows the regular ring (back) and the sanded down ring (front). I sanded down the ring to fit. Maybe from working in the dark barn w/o sufficient lighting for this, notice the loose fitment on the front ring it slants downwards.

 

[slambox28]

new tool for someone that doesn't have a hot dip tank! THese components were filthy from being in the barn for a while now but able to clean it very well. Storing clean stuff in the backseat of a car now

 

[Woodslasher]

Let's try this again. When the "sticking" was occurring was the coil and/or flywheel on the saw? I'd bet $20 the piston was not touching the cylinder. The flywheel magnets pass the coil around top dead center, giving the impression that the piston is touching the cylinder when it actually is not. The poor running is probably caused by old, dirty fuel. Maybe an air leak or carb issue, maybe not. Also, fyi "locked up" means physically unable to pull over, not "not running"

 

[Czed]

Oh here is the original cylinder
View attachment 436268

Would you like to sell that?
I'll buy it if the plating is good.

 

[slambox28]

Let's try this again. When the "sticking" was occurring was the coil and/or flywheel on the saw? I'd bet $20 the piston was not touching the cylinder. The flywheel magnets pass the coil around top dead center, giving the impression that the piston is touching the cylinder when it actually is not. The poor running is probably caused by old, dirty fuel. Maybe an air leak or carb issue, maybe not. Also, fyi "locked up" means physically unable to pull over, not "not running"

The difference before and after: the "catch" doubled or more, the cyl release does nothing anymore to effect the difficulty to pull in comparison. The saw seemed to mechanically lock up on me during use abruptly (just a description of it's behavior) but it still could turn over afterwards. It didn't actually "lock up" as in weld the piston to cyl. But the after effects is enough to drop your stomach. This catch is nowhere near the same as before. THe only reason to think its hitting the cyl is from the ring impression found on the piston. And from a YT video mentioning the possibilities of certain cranks stretching.

 

[Czed]

The difference before and after: the "catch" doubled or more, the cyl release does nothing anymore to effect the difficulty to pull in comparison. The saw seemed to mechanically lock up on me during use abruptly (just a description of it's behavior) but it still could turn over afterwards. It didn't actually "lock up" as in weld the piston to cyl. But the after effects is enough to drop your stomach. This catch is nowhere near the same as before. THe only reason to think its hitting the cyl is from the ring impression found on the piston.

Use thin solder and do a squish measurement.

 

[slambox28]

Would you like to sell that?
I'll buy it if the plating is good.

It seems to me like it's in good enough condition to run it! Cyl to piston fitment is the same as brand new! I'd consider selling it but also would like to use it when in like new shape. Just need to figure out the actual problem; why it seems to have a mechanical issue. And btw the new farmertec kit has a visible crack in the piston and squish band area.

 

[Czed]

It seems to me like it's in good enough condition to run it! Cyl to piston fitment is the same as brand new! I'd consider selling it but also would like to use it when in like new shape. Just need to figure out the actual problem; why it seems to have a mechanical issue. And btw the new farmertec kit has a visible crack in the piston and squish band area.

Does the oem cylinder have clearance issues with the farmertec piston?

 

[slambox28]

Use thin solder and do a squish measurement.

Oh, that's how it's done?

Here's what I'll need to do:
finish cleaning all parts
order a case gasket and sealant
then assemble with the old cyl and piston to get a measurement
...now when knowing it's not the piston tap I better keep looking

Crank bearings: they have no play at all and a very tight fitment, not loose at all. Seem to be in brand new shape. But now after more and more testing I've realized they might not just have debris. When fully rotating several times in the same direction it starts to catch every time; after several rotations of the inside race in the same direction. (the bearings are in the case still). But moving back and forth like before they seem like brand new. Not when going in the same direction though. Before, I thought it was just some debris but after cleaning and spinning, blowing them out and adding oil the "debris" is not going away? Maybe it actually is the bearings?

 

[slambox28]

Does the oem cylinder have clearance issues with the farmertec piston?

The farmertec piston wont fit it, here I've got a way to demonstrate squish right away: Next posts