MS 460 tuning for hi

[9ninjas]

Just got a tach today (tech data) because I wanted to check the max rpm on my 460. First warmed up the saw and checked the max rpm with the b&c attached - read about 14300. Next pulled b&c and checked and it read about 15200. According to Madsens site w/o b&c the 460 should read about 13500. The hi speed adjusting screw still has the cap on it and is screwed all the way out (3/4 turn). I live at about 5400 ft. so would figure it would be running rich anyway, so I was shocked when I got the readings. I tried it a couple of different times with the b&c off and got about the same readings. It seems to cut well but I sure as heck don't won't to risk burning it up because it is too lean. Should I remove the cap on the screw and riching it up even more to lower the rpm????

 

[pioneerguy600]

Sounds a little lean to me especially on a stock saw, I would try removing the stop and richen it up an 1/8 turn.
Pioneerguy600

 

[smokinj]

sounds a little lean to me especially on a stock saw, i would try removing the stop and richen it up an 1/8 turn.
Pioneerguy600

+1

 

[wigglesworth]

I try not to run one WOT with the bar and chain off. If you have ever sent a clutch spinning across the shop, you would understand. Now to the question, I think that 14.3K is way high for a stock saw. As Jerry said, richen her up a bit.

 

[9ninjas]

460 hi tuning

So, what once I remove the tabs on the screw, with the b&c put back on, what rpm should I tune it for, 12500 or so??

I'm just surprised at this altitude and the screw backed all the way out that it would be turning that high.

 

[wigglesworth]

So, what once I remove the tabs on the screw, with the b&c put back on, what rpm should I tune it for, 12500 or so??

I'm just surprised at this altitude and the screw backed all the way out that it would be turning that high.

I would try out 13.5K and see how she pulls. The WOT setting is gonna have a lot of factors around it, like bar length, hard wood or soft, and mainly how it feels in the wood.

 

[rxe]

I was tuning a 460 only this afternoon. A complete rebuild. Set high and low to 1 turn out, and pulled the starter, the idle was spot on at 2500. Goody, now for the high end. Pulled the trigger and 14,000 was the max - ouch, 13,500 is the recommended. Gave the high 1/8 of a turn, same - 14,000. Gave it another 1/8th. 14,000 again. Ok, gave it half a turn, still 14,000, and when I released the trigger, it coughed and died.

Oh no, the piston!

Then I looked a the rubber bung with the H & L markings - ah. I'd been adjusting the L, and the saw had quit idling at 2 turns out. A quick reset on the idle, then tuned it to 13,000 - so a little bit of headroom over the recommended limit.

I'd go for 13K if it is an average day - remember saws will run leaner in the winter (denser air), so tune to the recommended in winter, and a scratch lower in summer.

Runs like a champ!

 

[Showme]

All of my 460's have DP mufflers, two are also ported. The stock (new) one is turning a conservative 12,800 for a tank or two and then I'll lean it out a bit. One ported one is turning 14,250 and it's a little rich, I'll most likely lean it out a little more the next time I use it. The 440/460? Well we won't even go there as it's on the ragged edge. I just kind of like it for GTG's and such.

 

[blsnelling]

Never run a saw at WOT without the B&C. Your saw should be tuned to 13,500 with the B&C on.

 

[9ninjas]

Thanks guys.

Is there a table posted somewhere that shows the hi speed tuning rpm for different Stihl saws. I have 4-5 saws now (the 460 is the biggest) that I would like to check the hi speed tune for now that I have the tach.

 

[9ninjas]

I just got the b&c put on and moved the hi speed out 1 full turn to start. Still tached at 14200 so at about 1 1/4 turns out got her to 13400-13500. I didn't realize how touchy the slighest movement would affect the reading. So, I'm happy now and sure will sleep better tonight. She sounded good so I just hope I didn't do any damage running her up to about 15000 or so w/o the b&c before, maybe for about 5-7 seconds a couple of times. I am running the stihl HP super at a 50:1 mix in her and my 025.

 

[mtngun]

Is there a table posted somewhere that shows the hi speed tuning rpm for different Stihl saws.

For some Stihl models, not all:
http://www.getsaws.com/S_specs.html

 

[rxe]

Anyone who wants the tuning and setting sheet (18 page pdf), drop me a PM. It is the most useful Stihl doc I have.

 

[stevohut]

I just got the b&c put on and moved the hi speed out 1 full turn to start. Still tached at 14200 so at about 1 1/4 turns out got her to 13400-13500. I didn't realize how touchy the slighest movement would affect the reading. So, I'm happy now and sure will sleep better tonight. She sounded good so I just hope I didn't do any damage running her up to about 15000 or so w/o the b&c before, maybe for about 5-7 seconds a couple of times. I am running the stihl HP super at a 50:1 mix in her and my 025.

Should be fine, you will throw a bearing or a rod before you run out of lubrication. Should never run an engine without any load or resistance on it. 13500 is perfect that's what I have my 460 running.

steve

 

[Steveo_supremo]

Anyone who wants the tuning and setting sheet (18 page pdf), drop me a PM. It is the most useful Stihl doc I have.

PM sent