Working on a 570

[customcutter]

I bought a 570 a couple of weeks ago at the pawn shop. I asked if I could start it up, the guy said sure, so I took it outside and it started right up. I could tell the compression was a little low from pulling on the starter cord. They were asking $230, so I tried to talk them down, told them all the problems the saw had etc. No budge. So I left. I came back 3 hrs later with some tools and asked if I could pull the muffler, guy said sure. so I pulled the muffler, and could see light scoring, on the piston, but not too bad. I told him about that but still no budge. I bought it.

I pulled it apart, and cleaned up the Al transfer on the cylinder. I also tried to clean up the piston by "shoe shining" the section with some 120 then 320 emory tape. I also noticed a few rough spots on the ring so I "rolled" the edge on a hard arkansas stone till I cleaned it up. I wasn't happy with the piston so I got some 220 wet/dry on my pink inspection plate and "rolled/scraped" the piston on it, and then followed with 400 grit. I could feel lumps when rolling it on a hard surface before doing the final procedure.

The piston ring is .-078" on the sides and .o775 in the front. I measured 2 other sets of rings I have for a 365 and a 372 and they measure .079". Should I replace the ring or will I see much improvement?

The squish is .038" and I would like to do a gasket delete but there is a gap of .0035" between the 2 case halves. Thinner gasket material? or no gasket and 1184?

What other easy mods. I saw where Weimedog raised the bottom of the cylinder on a 365 I think .030", but don't remember if it was intake or exhaust side. I think it was exhaust?

thanks,
Ken

 

[backhoelover]

need to do a pressure and vac test, the bearings on them saw has the seal built into the bearing and are known for leaking. take the saw to your local husky dealer and have them hook up carb and coil to see if it has thrown any codes. you can also look at the h and l graphs and see if the saw has been running lean or rich and for how long. why they have the carb might as well have them check and see if it needs any firmware updates for the saw.

FYI i have the software and i do updates and check for cost of shipping to help guys out. if you want you can send me the carb and coil if you have a iphone we can facetime and you can see first hand what i am doing.

 

[customcutter]

I'm new to CS's but I don't think all of that would apply to a plain jane 570 would it? Maybe the XP models? Yes, I plan on a pressure/vac test when I put the cylinder back on.
It was definetly lean to damage the piston and transfer the little bit of Al. No Iphone,dang phones are smarter than me.

thanks,
Ken

 

[backhoelover]

does the carb have high and low adjustment needlee? here is the service manual

 

[backhoelover]

is there a black box on top of the carb?

 

[customcutter]

There is a high and low adjustment needle on the carb, but no black box on the top, that I saw anyway. Shiny chrome cap.

 

[backhoelover]

good than you have a reg carb

 

[customcutter]

Thanks for the offer and the manual.