Pro Mac 610 running lean?

[McCulloghProMac]

I am new here and hoping someone has a suggestion(s).

I have a Pro Mac 610 which ran great for many years. It will only run, when warm, with the choke out just a touch. This obviously makes cutting difficult because as soon as you throttle up it bogs down. It will idle with the choke slightly out but will not reliably stay running to cut with. I've torn it down checked the cylinder, rebuilt carb, new coil, checked for leaks, replaced fuel line and filter and am just plain ready to scrap it for parts.

I had to buy a Husky, to get ready for winter, starts everytime and I love it but, it's not my 610.

I've searched here and found numerous mention of similar trouble but no noted solutions. Any help would be appreciated.

 

[stihltech]

gasket

Check the gasket stack between the carburetor, air filter housing and the cylinder. I have found many of the 10 series with just this problem, new gaskets were the cure.

 

[Wood Doctor]

I also have a fondness for my old Pro Mac 610. I have noticed through the years that the carb adjustments for both the high and low speed throttle have to be on the money for the saw to run correctly. Otherwise, the idle speed doesn't mean much and she will die.

It sounds like it's starved for fuel if you have to choke it slightly to keep it going. I would close both the high and low speed carb screws completely and then open them both up only one turn. Start the saw, let it warm up a little, and make very minor adjustments from there. Adjust the idle only after performance is optimal.

Don't give up. It was a whale of a saw and in its day and there were few firewood saws that could touch it.

 

[McCulloghProMac]

Thanks, I will try both suggestions and try to get it running. My father has been a lot of help in trying to solve this issue, has experience with this saw and is also stumped.