372XP advice
- Thread starter jspell
- Start date
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Yup looks wiped, you could possibly save the cylinder though. I use scotch brite pads from ace to remove any aluminum transfer. If your wanting brand new I dont blame you however.
They are pretty good saws to disassemble.
They are pretty good saws to disassemble.
I've cleaned up worse and they are still running.
I make a mandrel using emory cloth
And a drill and take the transfer out.
Mastermind has a vid on YouTube
You can make a mandrel out of anything
I use Bic pen tubes often.
Looks like it's only aluminum transfer. Doesn't look like it broke through the nikasil. If you got some muratic acid , soak a q-tip and dab it on the score marks. It will loosed the aluminum. Take your time and it should clean up. Neutralize the acid in water after and then clean the cylinder again with some brake kleen.
One thing on those 372xt saws is that they have a rev limited coil and to tune them properly you need to use a tach. I think 12,300 or 12,500 is max rpm out of the cut.
One thing on those 372xt saws is that they have a rev limited coil and to tune them properly you need to use a tach. I think 12,300 or 12,500 is max rpm out of the cut.
Try cleaning it up, the only spot I see that would give concern is boxed in red below, I cannot tell from the pic if it is transfer or if it is scoring. If it's just transfer then you are only looking at a piston and rings, If there is scoring then you are looking at a kit. I'm guessing the dealer was meaning scoring when he said pitting.
That saw was not straight gassed. I would raise holy hell with the dealer until they replaced it.
Patrick1903
ArboristSite Operative
So what do you estimate would have cause that?
Lean condition.
I think the intake side of those strato pistons stay pretty cool with the air and fuel charge. It is a much longer piston then the OE 372 and therefore would be a much larger heat sink . I'm thinking when the dealer tech did his little fix with your carb, he got lazy and just leaned it out and never actually put a tach on it and really diagnosed the problem. Slowly over use it was to lean and got extra hot one to many times and then said enough is enough. Lol.
Of course the tech or dealer would never admit that I'd they are shady. Finding a good dealer is key these days and they are getting less and less.
Of course the tech or dealer would never admit that I'd they are shady. Finding a good dealer is key these days and they are getting less and less.
Backstage
ArboristSite Operative
I agree, but walk us through what your eye is seeing there.
It's seized on the exhaust side only. Straight gas will seize 360 degrees.
Only one thing causes a seizure on the exhaust side only and that's a lean condition.
He mentioned the "dealer" adjusted the carb. I would bet money they leaned it out to far.
Strato saws always run hotter than traditional two strokes. Much less fuel passes through them and fuel going through a phase change from liquid droplets to vapor is where the vast majority of the cooling comes from.
For the same reason they are always less lubricated as well as less oil goes through them.
Fix it yourself. The knowledge that you will learn will be worth ten times what a cylinder kit costs. If you need assistance, there are alot of very knowledgeable folks here that will lend a hand. Get yourself a good set of T handle hex/allen and torx drivers so you can take it apart easily. Order a gasket set with a set of seals and an after market piston and get to work.
You're right, I asked if I could watch when the mechanic adjusted it, he did not use a tach.
Thanks for all the replies. Sounds like what I'm hearing is that the damage pattern means it was probably leaned out too far, but I should fix it myself because the dealer won't take responsibility, and the time and headache isn't worth dealing with the dealer plus I'll learn a lot. I'll talk to him again armed with more knowledge but I'm happy to fix it and learn something. The dealer did offer me an OEM piston/cylinder at cost ($137)? But sounds like I should try cleaning it up first and see if that works.
Backstage
ArboristSite Operative
I’d give the dealer a chance to make it right all else equal. But not if I needed it up and running asap with no margin for drama.
BrettS
ArboristSite Operative
If you can get the OEM cyl/piston at cost I would jump on it, if the old cylinder doesn't clean up then you have it to use.
The area in question that is outlined in your picture - run your finger nail over it, if its scoring you will feel it and if it's just staining you should not feel anything,- personally if the dealer is willing to give it to you at cost I would go for it as long as it's not a long wait to get it.
