I know this isn't how you do a plug read But this is what I got after cutting about 7 cookies in about a 36"oak that's been down for 6 months. It did idle for a few seconds between cuts. Runnin a cj6 and 14,200 rpm's. Stihl ultra mix at 40:1 90oct ethanol free.
Looking at the plug after cutting.
- Thread starter davhul
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I know this isn't how you do a plug read But this is what I got after cutting about 7 cookies in about a 36"oak that's been down for 6 months. It did idle for a few seconds between cuts. Runnin a cj6 and 14,200 rpm's. Stihl ultra mix at 40:1 90oct ethanol free.
Chris-PA
Where the Wild Things Are
That didn't work out so well for Anakin.
kinda what I was thinking. It was 90 degrees today and on a fresh port job and 7 degrees of timing and I had no idea how it was going to act. Might try 14,500 next time and do a read on it. Is that a good heat range to start with
Chris-PA
Where the Wild Things Are
It looks normal to me, but plug color isn't very relevant given the way these carbs work. Was it 4-stroking when you lift? That is all that matters. The max no load rpm means nothing once the saw is modified.
Chris-PA
Where the Wild Things Are
It should just stop 4-stroking when you have it under load, and begin when you lift. If so then it is good.
The fuel mixture on these carbs gets very much richer with just a small increase in air flow, and leans with a decrease in air flow, so you want to make sure it is correct under load. You can best tell that by listening for the switch from 2-stroking to misfire/4-stroking.
At for max rpm, you adjust that solely by turning the H screw. What difference does it make if you turn the screw 1/8 turn while the saw is screaming at WOT and you're looking at a tach, or you make the same adjustment while the saw is off sitting on your bench? There isn't any way to know what the right number is once it's modified, so you have to tune by ear.
I'll pay more attention to that. It's not as noticeable in the vid but it's 4 stroking a little harder than it sounds.
From my point of view it looks rich. I adjust the carbs by sound and feel. I never look at the plugs, but that is just me. A more specific method would be to cut a few rounds and while the saw is at full song stall it or chop the throttle and hit the kill switch. If it is still dark turn the H screw just a bit and check it again. Thanks
Good advice given here. Forget the plug and tune it by ear. A well trained ear will readily pickup that you're 4-stroking immediately when you let off the load and 2-stroking immediately once load is applied. You are definitely not on the lean edge, although that is a good safe work tune.
Thanks that's good to know. It sounds and pulls good. I'm going to have to wait a month before I start on my 064. I got it free. Customer put a top end on it and it seized again. Gave it to me and I later found out he had the carb to lean and was mixing by eye.
I see what your saying I haven't thought about that's what's happened during that period. I guess if you do it this way enough you learn what sounds a little rich side or lean side of the tune. I know this is a whole other debate but I read people runing different oil ratios. I'm running 40:1 as always and thinking I should drop to 32:1.
