Posted by Steve in ID on April 21, 04 at 06:59:24:
In Reply to: Re: Carb tuning... posted by ICON on April 21, 04 at 05:21:12:
Icon, there comes a point where sometimes only a saw shop and/or a new carb fixes the problem...it's a 2 stroke mystery I haven't yet understood.
For mixture, start with both screws around 1-1/2 to 2 turns open. You might have to give the idle speed screw a tweak to keep the motor running while you do the adjustment.
Let the saw warm up and adjustthe low speed screw back & forth until the engine accelerates without coughing. Adjust the high speed screw with the throttle wide open until the engine just begins to 4-cycle. You can fine tune it under load (cutting through a log), but it should take two guys...one to hold the saw & the other to adjust the high speed screw.
Biggest causes of carb problems I've seen are eyeballing the gas/oil mixture (try a baby bottle to measure the oil precisely); leaving gas in the saw for longer than a couple of weeks if you're not goint to use it; and not changing the tank filter on a regular basis.
hth
Steve
: Do you think the float setting, or what ever it's refered to in 2 stroke engines needs adjusting and how do you set it?
: You mentioned it's really easy to set these too lean, how do you NOT set it too lean, hi idle adjustment or lo? What i usually do is try and set them to factory then minor adjustments to get it sounding good. I also heard that it's better to set the high idle first then low, but this is in regards to an old outboard motor so i don't know if it'd apply to all 2-strokes. Thanks for any advice.