288xp cyl question…run it or pitch it…

[singinwoodwackr]

I'm in the process of assembling a 288 project saw. All OE. After cleaning things up there is a small scratch, maybe .6mm, in the exhaust side, enough that I can feel it. I have smoothed it out with 220 and 320 paper.
Can I still run this, or, is this a candidate for full replacement?
I have a new ring and the oe piston cleaned up ok.
I was thinking of doing some mild transfer porting just for fun.

Another q...
I was thinking of removing the little "wings" on this piston. Aftermarket ones don't have them at all.

 

[singinwoodwackr]

Found one old thread. Seems, “run it” is the consensus there
wont be perfect but will cut wood.

 

[Woodslasher]

If it's your saw and will be your saw, I'd say run it. Leave the wings, though, they add extra stability to the piston and on a worn piston I'd leave them on.

 

[singinwoodwackr]

If it's your saw and will be your saw, I'd say run it. Leave the wings, though, they add extra stability to the piston and on a worn piston I'd leave them on.

Yea, will be added to the collection. If ever sold all will be revealed to a buyer

 

[cookies]

If you are going to actually put the saw to work i'd put a new oem piston in it, if its a dust collector I'd stick a new ring in that piston, reassemble, test run then shelf it.

 

[singinwoodwackr]

If you are going to actually put the saw to work i'd put a new oem piston in it, if its a dust collector I'd stick a new ring in that piston, reassemble, test run then shelf it.

I'm not as worried with the piston as with the cylinder. I've seen many pistons used here over years that were in a lot worse condition.
It is getting a new oe ring

 

[Jasonrkba]

Id replace the piston if it where mine. To many affordable options not to. If money is not the issue go oem if you are trying to save buy a Hyway, meteor or if dukes has a moly get that one.

 

[singinwoodwackr]

So, no one thinks this cylinder is bad? Pistons are a lot easier to source so, if I can use this jug it would be a lot better.

 

[Mad Professor]

It's above the port so you are going to loose some compression. Maybe do a base gasket delete to compensate?

 

[singinwoodwackr]

It's above the port so you are going to loose some compression. Maybe do a base gasket delete to compensate?

So, JB and sandpaper won't work?

 

[singinwoodwackr]

It's above the port so you are going to loose some compression. Maybe do a base gasket delete to compensate?

Or, a pop-up.

 

[cookies]

Or, a pop-up.

I would not suggest a pop up but a new oem instead, its a good point in making a thinner base gasket to increase compression to offset the losses from the gouges. The point is to get every advantage in increasing compression possible, the original piston is gouged and the bottom 1/3 is worn smooth. Pistons are tapered for a reason, wear the bottom some and it will further take performance away due to seal loss, heat transfer and oil retention. I prefer the use of copier paper as a gasket then copper coated over sealant, others prefer sealant. I find sealant makes cylinder removal later more work and often gets over applied causing it to come loose later into the crank cake.

 

[Bob Hedgecutter]

So, no one thinks this cylinder is bad? Pistons are a lot easier to source so, if I can use this jug it would be a lot better.

No, everyone does think its bad- just hoping its not too bad.
Because it is your own saw and not a slap up and sell- all good, if it peels around the score- no harm no foul, you just deal to it when and if that happens.
If it is through the plating- then its a 50/50 call.
Measure the skirt clearance on that piston- looks to be no original machining marks left so it is probably due to start the slappity slappity thing.
Main concern might be tracking down what left the scores and fixing that first.

 

[singinwoodwackr]

No, everyone does think its bad- just hoping its not too bad.
Because it is your own saw and not a slap up and sell- all good, if it peels around the score- no harm no foul, you just deal to it when and if that happens.
If it is through the plating- then its a 50/50 call.
Measure the skirt clearance on that piston- looks to be no original machining marks left so it is probably due to start the slappity slappity thing.
Main concern might be tracking down what left the scores and fixing that first.

Ha, no, I would never sell something like this without full disclosure…if even then.

I am starting to rethink his build entirely, however. The saw came with a nice 2100 that was the main saw I was after. So, I didn’t actually pay too much for it.
I cleaned up the OE bearings but they are just a tad sketchy…not getting warm fuzzies from them after assembling the case. $35 for new skf and seals so that’s a no-brainer.
This may get thrown back in the box for later consideration at this point. It is starting to look like an extreme hard use saw. Came from WA state, so…
crank seems ok but i do have a nos kit if needed. I have plenty of time so no need to rush it.

this cylinder will “work” but for how long…

 

[Jasonrkba]

Replace those bearings and seals. Sounds like a time bomb to me. To nice of a saw to chance. $110 for a hyway piston and cylinder kit, $18 for a gasket kit. Then you have a chip slinging "mocheen".

 

[singinwoodwackr]

Replace those bearings and seals. Sounds like a time bomb to me. To nice of a saw to chance. $110 for a hyway piston and cylinder kit, $18 for a gasket kit. Then you have a chip slinging "mocheen".

Looking like the right direction…
pitty this cyl is toast with just that little scratch.
I’ll use it as porting practice

 

[lone wolf]

So, no one thinks this cylinder is bad? Pistons are a lot easier to source so, if I can use this jug it would be a lot better.

Well, it ain't great, but I think it will work pretty good. Run it and see.

 

[Bob Hedgecutter]

Looking like the right direction…
pitty this cyl is toast with just that little scratch.
I’ll use it as porting practice

Its not toast- just comes with some associated risk.

Go over the whole saw- check the PTO side case around the spike mounts to clutch recess for cracks- they are prone.
Get a real good look at the edges each side of the rod big end bearing and see if a bit of that is responsible for the scoring.
Things like that will help decide the risk it or part it decision.

 

[huskihl]

Looking like the right direction…
pitty this cyl is toast with just that little scratch.
I’ll use it as porting practice

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

 

[singinwoodwackr]

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

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