CArb tuning the Madsens way..a problem though.

[mboln52000]

I wanted to really dial in my low speed idle on the 066 this weekend. So, i warmed it up good, and set out to do it the way they describe it on the Madsen's webisite. I do it this way to my 024 a couple times a season, and it works flawlessley, so does my 036 pro hybrid, but the 066 isnt working out.

When I start leaning it out by turning the low screw in, it should slightly increase in idle, and then drop off and almost die, or blurble. Then i note that location of the idle screw, and richen it up by backing it out, untill it barelly hesitates and runs a little rough. Then i would set the low idle right between those two points.

The 066 never changes idle as i turn the low speed screw in. I can bottom the screw out lightly on the seat and it still runs okay. Since i couldnt get it to set right, i backed it out, till i got a nice puff of smoke with each throttle blip.

The air filter looks clean enough, but could there be too much oil in it from sprayback, causing the saw to run rich all the time?

Thanks,
Matt

 

[cbfarmall]

Is your high side too rich? You may need to set both screws to 1 turn out and start from there. Remember, the high speed circuit also feeds the saw at idle just the same as the low speed circuit feeds at high revs. Does this 066 have the speed LED above the adjustment screws?

Chris B.

 

[mboln52000]

Nope, I dont have the led, but thinking back...I did set the low speed idle first before, then i used the DET, and set the high speed idle last.

Thanks,
Matt

 

[Fish]

Get a full carb kit and change the needle and lever, etc..

 

[mboln52000]

Right on, Chris B.!

Yep, the high speed was way too high! It was running 13,600! I know they redline at 13,500, but thats a little high for me...probably why '66's have a lot of crank trouble.

I just started completely over, with each screw out 1 turn, and everything went as it should. Lastly i reset the highspeed to 12,500. I really should not have complained though,, I would rather it run rich anyway...which brings me to a new post!

Thanks for the input!

Matt

 

[cbfarmall]

If you leaned out the HS to drop the RPMS you may have some problems. Typically you richen to drop the RPMs almost to the point of 4-stroking.

Suggest you do as Fish says and overhaul that carb. For reference my 066 LS is set at about 1 turn out and the HS 1.5 turns. Yours will vary.