Question on high idle and high rpm after cuts on Dolmar 510

[NH_Wood]

Hi guys,

I have a Dolmar 510 and it sometimes runs fine, but also (after cutting for a while - engine hot), the saw won't return to idle following a cut - just keeps running at high rpm and sometimes even seems to increase rpms with finger off the trigger. Brought the saw to the shop about a year ago for the same issue, it seemed to run better for a while, but it's back to this problem. I was thinking it might have to do with the carburetor and might need to adjust the carb, but I'm no mechanic. Any thoughts? Cheers!

 

[smokinj]

If you have adjustment on that carb your H screw would need adjusted. I am thinking dont sure on your modle but should be a 1/4 up to 1/2 turn to the right to fatten it up a bit.

Listen to the sound wave its how I learn to do it!

http://web.archive.org/web/20051018212959/www.madsens1.com/sawtune.htm

 

[NH_Wood]

If you have adjustment on that carb your H screw would need adjusted. I am thinking dont sure on your modle but should be a 1/4 up to 1/2 turn to the right to fatten it up a bit.

Jay - is the adjustment screw obvious when I take the air filter off (I assume it would be there)? I'm a novice at this stuff. I'll get the parts diagrams and see if I can find it. Thanks! Cheers!

 

[smokinj]

If you have adjustment on that carb your H screw would need adjusted. I am thinking dont sure on your modle but should be a 1/4 up to 1/2 turn to the right to fatten it up a bit.

Jay - is the adjustment screw obvious when I take the air filter off (I assume it would be there)? I'm a novice at this stuff. I'll get the parts diagrams and see if I can find it. Thanks! Cheers!

It would be on the out side of the saw. Just a small whole with a scew and a small arrow telling you what way to turn it. (But I have never seen a 510)

 

[NH_Wood]

If you have adjustment on that carb your H screw would need adjusted. I am thinking dont sure on your modle but should be a 1/4 up to 1/2 turn to the right to fatten it up a bit.

Jay - is the adjustment screw obvious when I take the air filter off (I assume it would be there)? I'm a novice at this stuff. I'll get the parts diagrams and see if I can find it. Thanks! Cheers!

It would be on the out side of the saw. Just a small whole with a scew and a small arrow telling you what way to turn it. (But I have never seen a 510)

Jay - on page 6 of this link, it shows the two screws (H and L) for the U.S. model. So....the H screw will be accessed from the outside of the saw - do I wait for the problem to occur and then dial down until it stop, or try an adjustment and see if the problem stops? Thanks for your help man! Cheers!

 

[smokinj]

If you have adjustment on that carb your H screw would need adjusted. I am thinking dont sure on your modle but should be a 1/4 up to 1/2 turn to the right to fatten it up a bit.

Jay - is the adjustment screw obvious when I take the air filter off (I assume it would be there)? I'm a novice at this stuff. I'll get the parts diagrams and see if I can find it. Thanks! Cheers!

It would be on the out side of the saw. Just a small whole with a scew and a small arrow telling you what way to turn it. (But I have never seen a 510)

Jay - on page 6 of this link, it shows the two screws (H and L) for the U.S. model. So....the H screw will be accessed from the outside of the saw - do I wait for the problem to occur and then dial down until it stop, or try an adjustment and see if the problem stops? Thanks for your help man! Cheers!

I would tune it once it gets warm up...Weather condision alone can change things so listen to the sound wave then you can hear that saw at any time you run it.

 

[LLigetfa]

If the idle RPM varies, it is not likely to be an adjustment problem. More likely to be dirt in the carb, a supply problem, or vacuum leak somewhere.

 

[NH_Wood]

If the idle RPM varies, it is not likely to be an adjustment problem. More likely to be dirt in the carb, a supply problem, or vacuum leak somewhere.

Hmmmm.......that's a shop run for me......still worth adjusting to see if it solves the problem? Cheers!

 

[wkpoor]

Run on after a cut is a plugged diagram vent port on the carb. There was a bulletin to address this where they made a change to the air filter. They removed the port where filtered air from the main source is removed and a piece of foam is installed in place. Either way just see if that vent port is dirty.

 

[NH_Wood]

Run on after a cut is a plugged diagram vent port on the carb. There was a bulletin to address this where they made a change to the air filter. They removed the port where filtered air from the main source is removed and a piece of foam is installed in place. Either way just see if that vent port is dirty.

Wish I could, but I'm not sure what the vent port would be - my neighbor is a good mechanic, perhaps he can help - I just don't have the mechanical experience to diagnose and fix these problems. But.....your advice and from others can at least let me talk somewhat intelligently with the shop folks - real good guys (and they know I'm green with mechanics!). Cheers!