Ok, again, how about Max MS290 RPM... but with a twist

[dswensen]

Ok, so I love saws more than I NEED saws (see my signature). I have a "new" MS290 that has only been used for a few hours (like 2). It's out of warranty, so I did a muffler mod on it and re-tuned.

I know the factory says something like 12,500 max RPM, but here's the twist.

In reading after searching, I find that saws tend to creep up a little in WOT RPMs as they break-in. I tuned by ear and then tach-ed the saw, getting about 11,500 RPM. To my ear, 12,500 seems above the four-stroke fade out.

The question; think I can tune it up to around 12,000 or should I let it settle in where it is first?

 

[Saw Dr.]

Tune it to where it four strokes out of the cut, and cleans up under load. The stock RPM spec goes out the window the minute you start modding it.

 

[dswensen]

Tune it to where it four strokes out of the cut, and cleans up under load. The stock RPM spec goes out the window the minute you start modding it.

Understood. Would you EXPECT a lower RPM for optimum setting after a muffler mod?

 

[Saw Dr.]

No I would not. Life is, however, full of surprises. Tune it to where it runs right. The RPM spec is the manufacturers back door way of getting the mixture approximately correct on a stock saw.

Either way the muffler modded saw will have more power.

 

[albert]

The couple of 290's that I opened the mufflers on ran about 13,500 and still were abit rich.

 

[BiodieselNC]

Yeah my 290 (with muffler mod) will 4-stroke at 13,500 but i richened her down to 13,000 just to feel better..... they haven't come out with a cheap big-bore kit yet....