Proper procedure for adjusting carb with tach

[Lakeside53]

It's normal for a 361... and many others. Madsens info assumes you have an old carb that is 100% adjustible. Yours has a fixed low jet and the L needle adjusts just a portion of the flow. Same for most modern H adjustments.

 

[West Texas]

When you back the "L" jet out till it starts to stall, then crank it back in 1/8th of a turn. Turn it off and then start it again, it should be OK. Now I would use the tach to set the idle speed as recommended. Andy is reading this post and may have a better suggestion.

As he has already posted, the newer saws have limit stops that prevent you from setting it too lean in theory. They allow you to richen the jets a bit; but, some even have limit stops on how far you can turn it CC too.

 

[bytehoven]

When you back the "L" jet out till it starts to stall, then crank it back in 1/8th of a turn. Turn it off and then start it again, it should be OK. Now I would use the tach to set the idle speed as recommended. Andy is reading this post and may have a better suggestion.

As he has already posted, the newer saws have limit stops that prevent you from setting it too lean in theory. They allow you to richen the jets a bit; but, some even have limit stops on how far you can turn it CC too.

On tuning the 361...

Am I right that you set the idle (1) turn out from a soft set, make the "L" adjustment as you noted, then tach the idle back to 2800-3000?

When I 1st got my 361, the chain was crawling at idle and the dealer reset the idle. I don't know what the factory original idle was, but just wondered what I should do if the chain creeps after tuning at 2800-3000 speed idle?

Should the carb be retuned when we get back to warmer ambient temps?

 

[West Texas]

If the "L" jet is set for proper starting, and you've set the idle to 2800-3000 and the chain is inching forward, this means the clutch is engaging. This will often happen when you first start a saw; and, then disappear after the saw gets hot. But if the chain keeps inching forward and you've got the "L" jet set properly for starting, then back off the idle adjustment until the chain stops inching forward. Although the factory idle tach setting may be a certain figure; each saw and each condition (elevation, weather, etc.) may vary slightly, don't worry about it. But IMHO an inching forward chain is a dangerous chain, an accident waiting to happen.

 

[bytehoven]

Thanks West...

I had wondered if there might be a problem with my clutch.


I will check the current idle speed 1st. Perhaps my saw was just factory set with a hot idle.

I also wondered if the cold weather might have contributed to the idle/chain creep on the new saw.


Once I retune the saw if I have creep as when 1st delivered, I will just lower the idle enough to stop the creep.

Thanks

RJ
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