Jonsered 670

[Johnmn]

What were you getting for squish? I just rebuilt my 670 Champ and measured .024" with gasket deleted.

Now I'm suffering from an air leak somewhere on mine. It's got new crank seals and oil pump o-ring. I'm thinking I might need to put base gasket in, wondering if maybe cylinder base isn't square or something.

Did you replace the pulse line?

 

[mogulmasher]

I did not, all the lines on this saw are in great condition. However, I'm going to be digging into this saw again soon and will be checking over pulse line and intake boot for potential issues.

 

[Burchie70]

What were you getting for squish? I just rebuilt my 670 Champ and measured .024" with gasket deleted.

Now I'm suffering from an air leak somewhere on mine. It's got new crank seals and oil pump o-ring. I'm thinking I might need to put base gasket in, wondering if maybe cylinder base isn't square or something.

I checked the squish quite a few times all around the cylinder and got .013 up to .018. I was told that the 670 actually got tighter on the very outside edge of the cylinder so I didn’t dare take a chance. I would try putting the gasket on and see if it takes care of the issue. Not sure what year your saw is but mine doesn’t have an actual impulse line. It’s built into the rubber manifold and cylinder. Did you use a gasket material like hondabond between the case and cylinder? With my saw if you were to use to much gasket material you could block off the impulse notch between the case and cylinder.

 

[mogulmasher]

Wow that's tight. I measured close to the edge but not all around. My 670 is a '93.
Yes I used Motoseal to seal cylinder.

 

[Burchie70]

You could pull the carb off and try blowing air through the impulse passage. I usually try real low pressure just to see if there’s any blockage. My saw is an ’86