Farmboss question

Code54 · Apr 24, 2014

It seems my Farmboss (MS250) is growing tired. It can be fussy to start but run OK once started. It does seem a little down on power so I was thinking it may need a refresh. I have rebuilt mowers but never a 2 stroke chain saw so was kicking it around. I was not sure if I need to bore it then oversize the rings or do you normally just ring them with a hone?
Also is there a place that hops up the farm Boss saws a bit? I really don't need a larger saw but a little more power would not be a bad thing. I would consider sending it out if I would get something done to it reasonably. Any thoughts or ideas?

HillStreet · Apr 24, 2014

Code54,

You sure it just isn't filters and plug. I just tuned up my twenty year old 029 with new plug, air filter, and gas hose & filter and it made a big difference. Also pulled off the spark arrester screen and that was pretty clean.

When I was in the Stihl dealer buying parts, I looked really hard at buying a new MS290 for $399. Really thought about selling my saw on Craigslist and buying the new one. I cut a cord yesterday and a cord today with no trouble at all, glad I did not buy new (even though new is always nice, my saw runs just fine).

Coyote machine · Apr 25, 2014

There's an in tank filter, which if you haven't changed it, try that and see how she runs then. You could port it and do muffler mods to get more power, if the filter and a tune-up don't cut it. Try the arborist web site or similar to find out more about mods before you do any teardown.

Code54 · Apr 25, 2014

I bought a new air cleaner, new plug, and I will pull the filter in the tank and clean up the exhaust and see what happens... Maybe things are just plugged up.
THANKS for the ideas!

94BULLITT · Apr 25, 2014

Do you have a compression gauge? Check the compression on. It takes a lot of cutting to wear out a Stihl, even a non pro saw. For more power I would start with a muffler mod and retune the carb.

TreePointer · Apr 26, 2014

+1

Compression test, muff mod, and clean air filter.

A sharp full chisel chain (as opposed to semi-chisel) can make a noticeable difference.

Code54 · Apr 26, 2014

Thanks
I do have a compression tester - about what should a good saw read? I am going to look into the muffler mod and just purchased a new filter. Later tonight I hope to get into it a bit and clean/tune it all up. Looking forward to seeing the results.
Thanks again for all the help and ideas

94BULLITT · Apr 26, 2014

Code54 said:
Thanks
I do have a compression tester - about what should a good saw read? I am going to look into the muffler mod and just purchased a new filter. Later tonight I hope to get into it a bit and clean/tune it all up. Looking forward to seeing the results.
Thanks again for all the help and ideas

I'm not sure how much compression it should have. It varys from saw to saw. 100 is definitely too low. Somewhere in the 130-150 range is probably good. I tried downloading a manual for the ms250 but the website was down. When you screw the compression tester in TURN THE ENGINE OVER VERY SLOWLY. The threads of the tester may hit the piston and damage it. Once you see it turns over fine with the tester you can crank on it. I have a tester with an adapter that has a short set of threads that I use on saws. When you get ready to muffler mod it ask on here first, some of us may be able to give you some help. I have found there is a lot of good info on the older threads on Arborist site but most of the pictures are gone from the hacks. If you ask a simple question on AS the people are not very helpful.

newbury · Apr 26, 2014

Madsen's Welcome To Madsen's Online has some pretty good tutorials. Make sure you have the right compression tester. For instance with a long tube you lose a bunch of air, not so important in a 500cc cylinder, more so in a 50cc cylinder.

Mod the muffler regardless, that's surgery done at home with a Dremel and a cup of coffee. It's expensive to get a good piston mod compared to the base price of the saw.

I've 2 660's, one with a dual port muffler and one with a minor muffler mod and "wood tune" by Brad Snelling.
both seem to have a LOT more power than the stock 660. The DP was a simple add on from Bailey's, the other saw came "Snellerized" and I think the going rate is about $250/saw.

94BULLITT · Apr 26, 2014

newbury said:
Madsen's Welcome To Madsen's Online has some pretty good tutorials. Make sure you have the right compression tester. For instance with a long tube you lose a bunch of air, not so important in a 500cc cylinder, more so in a 50cc cylinder.

Mod the muffler regardless, that's surgery done at home with a Dremel and a cup of coffee. It's expensive to get a good piston mod compared to the base price of the saw.

I've 2 660's, one with a dual port muffler and one with a minor muffler mod and "wood tune" by Brad Snelling.
both seem to have a LOT more power than the stock 660. The DP was a simple add on from Bailey's, the other saw came "Snellerized" and I think the going rate is about $250/saw.

A compression tester should have the Schrader valve in the end of it.

HillStreet · Apr 26, 2014

HillStreet said:
Code54,

You sure it just isn't filters and plug. I just tuned up my twenty year old 029 with new plug, air filter, and gas hose & filter and it made a big difference. Also pulled off the spark arrester screen and that was pretty clean.

When I was in the Stihl dealer buying parts, I looked really hard at buying a new MS290 for $399. Really thought about selling my saw on Craigslist and buying the new one. I cut a cord yesterday and a cord today with no trouble at all, glad I did not buy new (even though new is always nice, my saw runs just fine).

FOLLOWUP: I am about halfway through cutting my 9 cords of log length firewood with my old Stihl 029. Saw runs just like new with new air & fuel filters and spark plug. It has plenty of power with a 20 inch bar with RM and RS chains. If it doesn't have the same power that it had 20 years ago I haven't noticed---I'm 20 years older too. The point is, it cuts through the oak and maple (8 to 22 inch diameter) without me struggling to get through it.

Last fall the saw was stalling once in a while at idle, but that no longer happens and it starts in 4 pulls.

Code54 · Apr 26, 2014

Thanks for the follow ups. Ended up having to help family tonight and never got to the saw, Hope to work on it tomorrow. I been reading a bunch of the Muffler Mod threads and that is easy enough. Hardest part sounds like tuning it. I did run by the dealer today and get some new muffler bolts and a carb rebuild kit. Figured if I am working on it may as well do it all.

Code54 · Apr 26, 2014

I noticed I wrote MS250, meant to say MS290 - my mistake, sorry!

newbury · Apr 26, 2014

Code54 said:
Thanks for the follow ups. Ended up having to help family tonight and never got to the saw, Hope to work on it tomorrow. I been reading a bunch of the Muffler Mod threads and that is easy enough. Hardest part sounds like tuning it. I did run by the dealer today and get some new muffler bolts and a carb rebuild kit. Figured if I am working on it may as well do it all.

I bought a tachometer to tune my saws and then tuning by ear works fine.
Saw Carb Tuning is a decent sound file to help.

Code54 · Apr 26, 2014

That will help. Thanks. Are tach for saws something special or expensive?

94BULLITT · Apr 26, 2014

Code54 said:
I noticed I wrote MS250, meant to say MS290 - my mistake, sorry!

I think it should have around 150 psi for compression.

After you muffler mod it back the high screw out about 3/4 turn for a base line then adjust it til it sounds like the saws in link newbury posted. You may have limiter caps to remove off the carb. You can use a screw and vise grips to remove them.

You should have a piece of wood to test the saw before and after the muffler mod. I use my phone to make a video then watch the timer on the video to see how much it improved.