MS360 Pro turning at 15,000 RPM

[oscar4883]

I like to set my saws up so that they clean up under some load. Personally a tach and tuning out of the wood don't help me a bit. When I slam the throttle out of the cut all I hear is a screaming engine unless the saw is really rich. Now if I put the saw in a log and run it, I CAN hear the burble there. My advice is to back that H screw out a 1/4 or even a 1/2 a turn and put the saw in some wood. Adjust the H leaner over a couple of cuts so that the saw cleans up when you apply a little pressure but 4-strokes when you lay off. That way you know you are rich enough and you won't have to mess with the tune much due to changing weather, etc. IMHO

 

[procarbine2k1]

Glad you got a handle on it... Those 360's are AWESOME saws! Definitely need richened up in stock form, but those early model emission caps make carb adjustments a breeze. Learning what to "hear" will get easier in time.

 

[GASoline71]

Read this...

Carb Adjustments On Pro Saws (Madsen's Saw Shop)

Gary

 

[mictrik]

Read this...

Carb Adjustments On Pro Saws (Madsen's Saw Shop)

Gary

I think you all are making good points! I read the Madsen's article entitled "Carburetor Adjustment On Pro Saws"; thanks for the link. I bought some chain from them a few years back and I remember that the person i spoke to on the phone was extremely knowledgeable and confident without an air of arrogance; your best kind of service provider!

The article places a great emphasis on using the tachometer to adjust the saw precisely, quotes below.

"You're also going to need a tachometer. It is difficult (for even a trained ear) to adjust today's saws as accurately as is necessary without a tach. We have adjusted thousands of saws and we use a tachometer religiously."

"NOTE: If you do not have a tachometer, set the RPM level so that the saw "four cycles" or "blubbers" at wide open throttle. Do not attempt to set at maximum RPM levels without a tachometer. Setting the adjustment slightly rich will diminish performance, but reduce the possibility of damage to the saw engine."

I downloaded and listened to the wav file they provided. Its a great clip of a saw being tuned from a rich condition. The wave seems to mimic the sound I heard. At present my saw hit maximum of 13600 but averaged just below 13500 at WOT. Idle speed averages 2700 RPM and acceleration seems almost instant. I will check it in a few days when I use it but my feeling is that the saw is now properly adjusted for power and safety.

While perusing the various posts in this site I noticed that great many people modify their saws by opening up the exhaust and and then adjusting the carb to accommodate. I would imagine that in doing so you are raising the max RPM of the saw? My thought on this is that you could be subjecting the internals (ie. bearings, crank etc...) to excessive wear do to achieving higher RPM than the engine was designed for. Lean seizure may not be a worry because you are scavenging the exhaust gases quicker aiding cooling. I would use a very high grade (synthetic) oil at maybe a heavier ratio if you do this.

I am curious what you all think about my thoughts...

Thanks again/Mick
:greenchainsaw: