288xp cyl question…run it or pitch it…

[Bob Hedgecutter]

What is normal comp for these saws? I believe it was running 175 before I tore it down.

Yeah thats in the "normal" range.

 

[lone wolf]

What is normal comp for these saws? I believe it was running 175 before I tore it down.

180 was what mine had, and that's enough to keep braking the pull start assembly on that one for some reason.

 

[singinwoodwackr]

180 was what mine had, and that's enough to keep braking the pull start assembly on that one for some reason.

This must be an older model…no decomp

 

[lone wolf]

This must be an older model…no decomp

Same with mine.

 

[Czed]

I’d run the hell out of that if it was mine. Those scratches are gonna bleed off maybe 10 psi compression.

I've ran much worse damaged cylinder no appreciable difference in power.
I do like those Duke's plated pistons have you run them?
I've used 7-9 can't remember of them.

 

[singinwoodwackr]

I've ran much worse damaged cylinder no appreciable difference in power.
I do like those Duke's plated pistons have you run them?
I've used 7-9 can't remember of them.

I only have experience with Meteor and Hyway.…other than OE.

 

[Hirdatron]

I recently refreshed a 181se with a similar looking cylinder. You could see the scoring but couldn't feel it running a finger nail over it. Everything else was good so I just replaced seals and gaskets, put it back together and it runs absolutely fine! Don't see what harm a scored cylinder would do anyway other than loss in performance? If it was 10psi down on a 185psi saw that's about 5%, or 0.25hp on a 5hp saw if they're directly linked. Might be different if it's a work saw but for an occasionally used hobby saw I really don't think you'd notice. And why would you use a 40 year old bone shaking, lead weight of a saw for work anyway?

 

[singinwoodwackr]

So, pulled it back apart. Slight up-down on the crank rod...no bueno
I have a nos kit. Question: the bearings in the kit have old grease or some sort of ancient lube. They turn but certainly don't free spin. Should I clean them in brake or carb cleaner to free them up? They aren't packed with grease like some older SKF bearings i've seen.
Also, the bevel is a bit different on each side. Do these have an in/out designation?

 

[singinwoodwackr]

I recently refreshed a 181se with a similar looking cylinder. You could see the scoring but couldn't feel it running a finger nail over it. Everything else was good so I just replaced seals and gaskets, put it back together and it runs absolutely fine! Don't see what harm a scored cylinder would do anyway other than loss in performance? If it was 10psi down on a 185psi saw that's about 5%, or 0.25hp on a 5hp saw if they're directly linked. Might be different if it's a work saw but for an occasionally used hobby saw I really don't think you'd notice. And why would you use a 40 year old bone shaking, lead weight of a saw for work anyway?

View attachment 1145036

The scratch on mine is easily felt with a finger tip, even after sanding with 220 and 320 emory

 

[singinwoodwackr]

Piston is 2.11" top and bottom.
It is an AB piston. No machine marks evident on the sides.

 

[huskihl]

What is normal comp for these saws? I believe it was running 175 before I tore it down.

Depends on the era I believe. That’s normal I’d say

 

[SteveSr]

If t he scratch is through the plating what are the odds that the plating will chip off and get into (and ruin) all of the bearings? The silicon carbide in Nikasil is harder than any bearing.

 

[Bob Hedgecutter]

I recently refreshed a 181se with a similar looking cylinder. You could see the scoring but couldn't feel it running a finger nail over it. Everything else was good so I just replaced seals and gaskets, put it back together and it runs absolutely fine! Don't see what harm a scored cylinder would do anyway other than loss in performance? If it was 10psi down on a 185psi saw that's about 5%, or 0.25hp on a 5hp saw if they're directly linked. Might be different if it's a work saw but for an occasionally used hobby saw I really don't think you'd notice. And why would you use a 40 year old bone shaking, lead weight of a saw for work anyway?

View attachment 1145036

Yeah but thats a different form of scoring and not likely to be through the plating- the OP's score looks like something hard and metallic has been between piston and bore, dragged up for a ways. They can be through the plating and lead to peeling- that is where the "harm" might show itself.

 

[Bob Hedgecutter]

So, pulled it back apart. Slight up-down on the crank rod...no bueno
I have a nos kit. Question: the bearings in the kit have old grease or some sort of ancient lube. They turn but certainly don't free spin. Should I clean them in brake or carb cleaner to free them up? They aren't packed with grease like some older SKF bearings i've seen.
Also, the bevel is a bit different on each side. Do these have an in/out designation?View attachment 1145043View attachment 1145042

You kind of have to weigh it up- is this saw worth a brand new crank?
Id the slight up and sown perceived or actual and to the point of OMG?
Is it worth putting a cylinder with a score on top of a brand spanking new crank?
Is running a worn piston a good idea.........

You get my drift? Go over the complete rest of the saw and if it is near basket case- are you putting lipstick on a pig?

 

[singinwoodwackr]

You kind of have to weigh it up- is this saw worth a brand new crank?
Id the slight up and sown perceived or actual and to the point of OMG?
Is it worth putting a cylinder with a score on top of a brand spanking new crank?
Is running a worn piston a good idea.........

You get my drift? Go over the complete rest of the saw and if it is near basket case- are you putting lipstick on a pig?

Yup, back in the box for reevaluation. The rod play is barely perceptible and if it had a coat of oil it would not be there. Just not zero-play like others I’ve evaluated. The nos crank kit should go on a fully restored, pristine example, IMO. This saw ain’t it

possible plan: Hyway P&C kit, seems to be closer to oe than meteor for this saw, recommended by Tinman, $115. Reuse the old crank. skf bearing/seals, $35.
open up the transfers a tad. Polish he exhaust port.

this saw will not be an everyday work saw, at least not for me…too old for that ****

These builds are all for fun and to add to my collection.

 

[Bob Hedgecutter]

Yup, back in the box for reevaluation. The rod play is barely perceptible and if it had a coat of oil it would not be there. Just not zero-play like others I’ve evaluated. The nos crank kit should go on a fully restored, pristine example, IMO. This saw ain’t it

possible plan: Hyway P&C kit, seems to be closer to oe than meteor for this saw, recommended by Tinman, $115. Reuse the old crank. skf bearing/seals, $35.
open up the transfers a tad. Polish he exhaust port.

this saw will not be an everyday work saw, at least not for me…too old for that ****

These builds are all for fun and to add to my collection.

Then use the cylinder you have and just chuck a new piston at it.

 

[singinwoodwackr]

Then use the cylinder you have and just chuck a new piston at it.

So, risk of plating peal will be relatively low with occasional use?
I thought about a pop up piston to compensate for compression loss

 

[lone wolf]

So, risk of plating peal will be relatively low with occasional use?
I thought about a pop up piston to compensate for compression loss

You said it had 175 was that before the damage or after?

 

[singinwoodwackr]

You said it had 175 was that before the damage or after?

When I got it. I never even ran it, just checked comp when it and the 2100 showed up.

 

[lone wolf]

When I got it. I never even ran it, just checked comp when it and the 2100 showed up.

Well, 175 is certainly good.