MS250-Too Much Compression?

[drf255]

Yes. But freewheeling vs. seating the rings against force. Two different things. V

Any car engine I've built gas been broken in by flooring under a load, never free revving.

 

[nmurph]

I put them together and rev them...no problem.!

 

[drf255]

sounds like its getting tuned and tached on Thursday

 

[TIMBERTRON]

this was a interesting thread

 

[drf255]

Yet one more question.

I noticed this saw is not a prolific oiler at all. It has a small hole in a metal plate where the oil comes out to hit the bar.

Can I drill the hole out larger for better flow?

 

[AKDoug]

Yet one more question.

I noticed this saw is not a prolific oiler at all. It has a small hole in a metal plate where the oil comes out to hit the bar.

Can I drill the hole out larger for better flow?

That won't help. They don't oil much. There is a higher flow oiler for them.

 

[drf255]

That won't help. They don't oil much. There is a higher flow oiler for them.

Where would I find one?

Do you above a PN?

I can't wait to get a good chain on this little saw and actually tune it correctly. I basically ran it super rich to protect things.

Will a tach reading tell me anything about the power difference vs. stock, or do they not correlate at all?

 

[Deets066]

If it were me I would run that saw at about 14,500-14,800 rpm

 

[blsnelling]

It MUST be tuned by ear now that it's modded.

 

[blsnelling]

Make another video, allowing it to free rev before you drop it into the cut. Do this a couple times. Also let up in the cut to take the load off the saw, and then let it bite back in.

 

[bluesportster02]

i would never just pick a number to set it too. go by ear

 

[AKDoug]

Where would I find one?

Do you above a PN?

I can't wait to get a good chain on this little saw and actually tune it correctly. I basically ran it super rich to protect things.

Will a tach reading tell me anything about the power difference vs. stock, or do they not correlate at all?

Part # 1123 640 3201, you will choke on the $30 price since it's such a small item. The other issue is that it's tough to tell which pump you have already and they require a special tool to install.

 

[drf255]

Fully cold. Open throttle. No oil in cylinder.

Hit my mark. Only have a half tank through it.




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[Deets066]

It MUST be tuned by ear now that it's modded.

That's why I suggested a range, yes it should be tuned by ear, but also should be close to that range

 

[drf255]

Alright.

So I sharpened the chain, which was dull. Hooked a tach up. Leaned it, then richened it to the point where it just 4 stroked a bit out of the cut.

If I can believe the tach, I leaned out to 20,500 rpm. I richened it up and left it at 13,500.

This is a video of me cutting 16" hard sugar maple. 18" .325 bar and RS full chisel yellow chain.

This little saw can throw some chips.




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[drf255]

I'm at 195 psi now cold.

I'm not understanding the tune.

If I'm really at 20,000+ lean, should I lean it out to a higher rpm than 13,500? I hear it 4 stroking out of the cut.

 

[old-cat]

You should hear a higher/cleaner sound when it gets a good bite in the cut. That's when it's in "tune".

 

[drf255]

Do u hear it in the video?

I don't get that "lean" sound in the cut.

It bogs a bit in the cut.

What's up with the 20,500 rpm?

4 stroking means a burble, right?

Should I lean it out, out of the cut, then just richen a bit?

 

[old-cat]

I can't hear a video as well as I can hear the saw right by me. On my saws I don't spend a whole lot of time getting to that "tune" spot, I'd rather have my saws run on the rich side.

 

[David Young]

this was a stock 025, I had it tuned fairly well but the saw was cold on the first cut and it was a litte doggy.
the last cut it is running pretty good.

Your saw doesnt sound like it is carrying as much rpm in the wood. I would turn it up a little. the stock wot is 14.5k if I remember.
I think you should put the ignition timing back to stock. Run it and get some vid. it may be faster with less advance.

I think you changed too many things at once to know how much you gained.
I would have ported and muffler modded it first
I would have tweaked the port timing if needed.
then look at the carb
then the piston/popup
then the ignition

Don't let me get you down though nice work and great initiative