440 mag max rpm

[Boomer 87]

Just put a new meteor piston and cleaned up the cylinder on my stihl 440 mag. Trying to tune it in the wood. Question is if i richen it up and cut then start to go lean untill i quits 4 stroking under load, when i lift it seems to be pig fat rich but back onto the cut it clears right up. So i guess i need a tach, but whats a good max rpm for that saw. I would rather stay maybe even 1000 rpm rich of that spec?

 

[TBS]

13,500 according to madsens.

 

[Boomer 87]

So i wonder if it would be wise to run it at 12,500 for a few tanks. What im wondering is right now its just lean enough not to 4 stroke under load, but 4 strokes very heavy unloaded. Should i lean it some or just leave it.

 

[Boomer 87]

Whats a good tach for saws. I see a bunch on ebay for so cheap it makes me nervous. What brand do yall use.

 

[Stihl-Pioneer]

Whats a good tach for saws. I see a bunch on ebay for so cheap it makes me nervous. What brand do yall use.

Fast tach is what I have. Works great. Pricey but worth it.


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[astnmacgto]

I think Dave sells fast tach, I could be wrong

 

[ferris076]

So i wonder if it would be wise to run it at 12,500 for a few tanks. What im wondering is right now its just lean enough not to 4 stroke under load, but 4 strokes very heavy unloaded. Should i lean it some or just leave it.

U don't need a tach, when the saw 4 strokes unloaded ur are fine.
Pur some tanks thru it and then u can go a little bit leaner

 

[Boomer 87]

Thats normally what i do but its harder to hear the 4 stroking @ 13,000. Im used to countervibes and homelites that run at 8500

 

[blsnelling]

So i wonder if it would be wise to run it at 12,500 for a few tanks. What im wondering is right now its just lean enough not to 4 stroke under load, but 4 strokes very heavy unloaded. Should i lean it some or just leave it.

There's no need to run that rich. 13,000 max.

 

[Boomer 87]

There's no need to run that rich. 13,000 max.[/QUOTE

So heres a question for you then if the saw runs clean in the cut but 4 strokes heavy @ 11k how can it run clean in the cut and 4 stoke lightly @ 13k and still be enough fuel. Seems like it would be lean to me.

 

[Boomer 87]

Its hard for me to put into words i guess. But to me runnimg clean in the cut is correct but unloaded its very heavy i bet its probly 11,000.

 

[blsnelling]

If it's lean at even 13,500, then something is wrong with the saw.

 

[super3]

11,000 for that saw is pig rich and will develop a lot of deposits.

You have been given good advise.

13,000 is plenty rich for break in.

 

[Boomer 87]

I do appreciate the comments. I dont believe the saw is lean. I guess im stumped as to if at 13k it fourstrokes lightly and runs good in the cut, if i fatten it way down to say 11k it still cleans up and sounds good in the cut. I would think it would still be 4 stroking even under load at that rpm but it doesnt it cleans up and runs well.

 

[Boomer 87]

Well i broke down and bought an edt9. So ill guess well see. I should of mentioned i open the muffler up considerable as well that will change the tuning.

 

[grizz55chev]

Well i broke down and bought an edt9. So ill guess well see. I should of mentioned i open the muffler up considerable as well that will change the tuning.

Pressure vac test? If not yer pissing in the wind.

 

[Boomer 87]

Im gonna do it again but yeah it was ok. My thing was if its burning all the available fuel does it any benifit any to go leaner?

 

[grizz55chev]

Im gonna do it again but yeah it was ok. My thing was if its burning all the available fuel does it any benifit any to go leaner?

Rev limited coil? If it's bouncing off the rev limiter this could easily cause you some confusion.

 

[Boomer 87]

I wondered that but i dont think it has one

 

[blsnelling]

The 044/440 has never had a limited coil.