Another ps5100 thread lol

[Chris J.]

I agree, i honestly think that the seller had no clue only because i could tell the saw had never been apart since new. I sent him a message about the issue. After cleaning everything up, the ring and piston look good as well as the cylinder. Im just thinking of putting it back together and running it. What do you guys think? Anyone ever been in a situation like this where the piston and ring seem to be still good after cleaned up.

Another thing i just noticed was that the paint on the inside of the crank case, on the flywheel side, is worn off. Ive never seen it that happen before. The crank is tight and the con-rod is good too.

Would you mind posting a photo of the cleaned-up piston? I have a Jonsered 920 with similar damage, probably worse than your 5100 though.

 

[mountainlake]

I'd let the seller off the hook, not many would pull the muff if it had good compression. Put it back together the way it is and it should work good, if not then get a piston , rings or cylinder. This saw was not lean siezed just not warmed up enough. Steve

 

[SawTroll]

So the guy who I purchased the saw from, wrote me back. This is what he said
"this saw is used, runs perfect, i dont know what else to say, maybe you should have bought a new one! comp was perfect."

I don't know how to go about this cuz the saw did have good compression, but he never checked the condition of the piston or cylinder. If i hadn't pulled the muffler off, i would have never known of the problem either. I already have the saw apart and repaired it. I'm not trying to be a jerk to this guy, but i want him to know about the problem. I purchased a new ps5100s 2 weeks ago lol, so that's one response to what he had to say. But then again it has nothing to do with me buying a new. It comes back to him not checking his saw over properly before selling it and improperly describing it. I feel like i'm just gonna get into a pissing match with this guy and he's gonna think im a scammer and all that blah blah blah.

Did you send him a link to this thread?

 

[ktoom]

I could get a better picture, but here's one of where it was scored.

 

[albert]

If I bought a saw off ebay, I would ask seller to pull the muffler and check piston. I have seen many saws with 140+ compression and scored pistons. I wouldn't worry too much about it.

 

[SawTroll]

I don't think you can blame the seller much, when the saw ran well and had 190PSI compression - not many will look at the piston when that is the case anyway.

Making him aware of your findings is right though!

 

[ktoom]

I've bought many saw's off of ebay and I knew what to expect. Sometimes you get killer deal and sometimes you get the shaft lol. I'm not complaining about the deal and I'm actually happy with the saw. I'm not looking for a refund from this guy because he had no knowledge of the issue. The seller sharpened the chain for me and cleaned up the bar too. I started this thread to get some opinions on the piston, to see if it was salvageable. Thanks for the help guys :hmm3grin2orange:

 

[bigwhiteash]

using badly scored piston/rings/cyl

I recently picked up a "parts saw" and found the P&C really scored[as I expected: the seller said it had 85 PSI]. After I cleaned up the cylinder it looked ok but not great. I filed and cleaned up the piston as much as I could. The ring grooves needed filing where the scoring occurred. The rings were terrible, but I filed and stoned them to make them smooth and round[?] again. I'm a pretty good hand man, with lots of tool and die experience so I prolly can do this better than a beginner. Anyway, nothing to lose , reassembled it carefully and cranked it w/2S oil in the cyl, then cleaned that out and fired it up. It starts well and runs well. I started going easy at first, warming up, not running too long. It did smoke at first, but is good now, even cut quite a bit of wood with it. It may blow but I'm glad Im tried reworking it, if just for the know-how. BTW, I cannot get OEM replacement parts for it. YMMV. J

 

[souliog]

A little tip you can try from my old 2-stroke MX days...wash the cylinder in muratic acid and use a 3m scrub pad. The scoring looks like aluminum and should come off. Follow that with a light hone and you will be ok...New piston and rings are a must IMO.

 

[woodyman]

I bought an 026 off ebay that had a hole through the oil tank.Got about the same answer from seller as you did except he told me I did not ask if saw had a hole in itAt 200psi cold and running lean and fast those 5100's can do some scoring:hmm3grin2orange:

 

[ktoom]

The seller was actually selling 2 5100's at the time. The one i bought was ending sooner. The second saw sold for wayyy more yet it had the same description and looked different. He had 2 picture's for each saw. Judging by the back round they were taken on a fork lift in a warehouse. I find it odd that this guy is selling 2 5100's and he's not a member on this site.......... or is he???????? I mean he had enough sense to check the compression before selling it, so i don't know? My friend is honing the cylinder for me and the saw should be back running soon. My friend actually build's race motors and even agreed that the piston and ring still looked good. Im gonna put the piston and ring back in it to see what kind of compression it has. If the compression is lower, im just gonna order a new piston. Or i could do a port job and muffler????? We shale see what happens.

 

[ktoom]

I got my cylinder back today. I put everything back together and did a compression check. It only got up to 160psi. Im gonna order a set of rings and go from there.

 

[J.W Younger]

I got my cylinder back today. I put everything back together and did a compression check. It only got up to 160psi. Im gonna order a set of rings and go from there.

I'll send you a self addresed invelope and PM you my addie if you send me the extra ring.
j/k i'm sure you know its a 1 ring piston.

 

[bullittman281]

I see I'm a bit late to the game but I say run the parts. I've "fixed" stuff that looked WAY worse than that. I healed a PP295 that was strait gassed like hard core. I sanded most of the aluminum off of the cylinder, sanded the rough spots off of the piston and ran it. I had a worn out ring from when I rebuilt my other one that I stuck in it. The chrome on the cylinder is pealing but it survived a whole firewood season and it still runs good. Your parts look perfect in comparison to my junk. Run it!

Bullittman

 

[Andyshine77]

I got my cylinder back today. I put everything back together and did a compression check. It only got up to 160psi. Im gonna order a set of rings and go from there.

Did you run the saw at all before you checked compression? or did you just but it together and took a reading? You need to at least make a few cuts to clean it out a bit. 160 is excellent compression btw, I'd run it.

 

[ktoom]

I'll send you a self addresed invelope and PM you my addie if you send me the extra ring.
j/k i'm sure you know its a 1 ring piston.

Hahahahaha just use to always saying rings, not ring lol.

I was debating on firing it up and using it for a little bit. What kinda stopped me was that usually the 5100's compression it around 200psi, so in my eye's 160psi is kinda low for this saw. Especially for the fact that the compression was at 190psi before i took the saw apart to clean up the scoring. I double check everything to see if anything was loose.

 

[J.W Younger]

Hahahahaha just use to always saying rings, not ring lol.

I was debating on firing it up and using it for a little bit. What kinda stopped me was that usually the 5100's compression it around 200psi, so in my eye's 160psi is kinda low for this saw. Especially for the fact that the compression was at 190psi before i took the saw apart to clean up the scoring. I double check everything to see if anything was loose.

For what its worth it was raining the day I brought my 5100 home so since i could'nt cut wood i checked the compression,it was 150psi.After 20+tanks it was 185.I wood at least run it some and re-ck it,if it was me.OTOH a ring dont cost much if you have the time.

 

[Andyshine77]

Hahahahaha just use to always saying rings, not ring lol.

I was debating on firing it up and using it for a little bit. What kinda stopped me was that usually the 5100's compression it around 200psi, so in my eye's 160psi is kinda low for this saw. Especially for the fact that the compression was at 190psi before i took the saw apart to clean up the scoring. I double check everything to see if anything was loose.

The ring will need to reseat before you'll get max compression.

 

[wse8562]

The ring will need to reseat before you'll get max compression.

Yeah, The 5100 will have much better compression after a tank or so of fuel. They seem to pick up more than most saws

 

[CHEVYTOWN13]

Yeah, The 5100 will have much better compression after a tank or so of fuel. They seem to pick up more than most saws

I recently ported a 5100 exhaust port to the low 90'sº and I expected it to spin like a top without any resistance once I bolted it back to the case for laughing gas.

To my amazement, it was the opposite. I never took a compression reading, but it feels like at least 160psi. It feels thumpy on 1 TDC pull. That's with the stock gasket on:jawdrop:

I'm not sure how Dolmar is doing it, but just keep doing it(Dolmar Ignition Module™)