carb setting question

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

DiscoInferno

Minister of Fire
I've had my completely stock 359 for a several years now, it was bought from a dealer nowhere near me so it's never been back. After breaking it in I tuned the carb once by ear, and haven't played with it since. Recently I bought a cheap tach just out of curiosity, to see if I was leaving any power on the table, so to speak. What I discovered was that the richest setting the plastic tabs would allow put me right up at 13500 rpm at WOT, which is the max for the 359. Turn it clockwise at all from there, and I cross 14000 rpm WOT pretty quickly. The setting I've had for years was reading over 14000. Is this normal/expected, due to EPA rules perhaps? The manual says it's "EPA I", whereas new saws seem to be "EPA III". Wasn't the saw supposed to be factory set rich for break-in? Are the listed max rpms conservative?

I suppose my tach could be overcounting, although I don't have any reason to suspect that.
 
Turning it clockwise will lean it up, causing it to run faster and burn up. Up against the tab is absolutely the leanest you should run the saw.
 
So it would seem. But I thought that tuning by ear, listening for 4-stroking, usually resulted in a slightly rich setting. Here that's apparently too lean, or at least too fast. I don't have much personal experience tuning saws, just going by what I've read.
 
Or, what you thought was 4 stroking wasn't because you didn't trim the limiter cap to hear what it really sounds like..
 
I suppose some trimming is in order, it's not like the saw is under warranty anyway. But then and now it sure sounds like the four-stroking on those .wav files that can be found online.
 
Status
Not open for further replies.