Jonsered 670 W Piston/Cylinder Question - Is it Toast?

[serdie]

check out this kit on ebay, 52mm Bore Nikasil Cylinder Kit Fit Jonsered 630 670 625 Chainsaw. It might be worth looking at. $75 US, it comes with a clutch cylinder piston crank bearings seals filters new oil pump. I wouldn't use the fuel line or the ignition switch but the rest of it may be good enough. If you go that route use the original oem piston circlips.

If you use the 52mm kit and domed piston, run it at 40:1 all the time. It WILL run hotter than usual. But it’ll rip!

 

[huskihl]

The scratch to the side of the exhaust port isn’t going to hurt anything. It will likely fill in with carbon in time and won’t even notice it’s there. It’s much better than running some Chinese cylinder that’s out of spec/round with terrible port direction and timing numbers. Show me a stock Chinese cylinder on a saw that has anything to do with winning a world championship and I will buy it for you

 

[huskydave]

I bought 3 670 saws that all ran for under 300 once, something to think about.

 

[Alphadelta]

I think it boils down to the user, it's a friend of mine who heard I was picking these up and wanted one. I doubt it will get used much, so I am going to buy the meteor piston, do my best to clean everything up and reassemble. If there is an issue with down the road I will address it then. For now it gets the saw up and operational without spending a ton of money into a saw that to my friend or myself honestly isn't worth all that much.

Thanks all for the input. It definitely saved me some money and a little bit of my sanity.

 

[huskihl]

I think it boils down to the user, it's a friend of mine who heard I was picking these up and wanted one. I doubt it will get used much, so I am going to buy the meteor piston, do my best to clean everything up and reassemble. If there is an issue with down the road I will address it then. For now it gets the saw up and operational without spending a ton of money into a saw that to my friend or myself honestly isn't worth all that much.

Thanks all for the input. It definitely saved me some money and a little bit of my sanity.

It will run fine. Make sure you do a vacuum/pressure test as I’m sure the seals are bad by now

 

[Alphadelta]

It will run fine. Make sure you do a vacuum/pressure test as I’m sure the seals are bad by now

I was shocked, obviously appearances can be deceiving but the seals look good. But I will 100% vacuum test it before I call it finished.

In your experience has the mightyac been the go to tester for that? I have a cheap one and I don’t like it much.

 

[huskihl]

I was shocked, obviously appearances can be deceiving but the seals look good. But I will 100% vacuum test it before I call it finished.

In your experience has the mightyac been the go to tester for that? I have a cheap one and I don’t like it much.

Most of the cheaper models only do vacuum. There are others but the MV 8500 is kinda the gold standard for doing both.

Can’t really see much by looking at the seals. I’ve changed hundreds and only a couple were obvious