Help cleaning up MS261

[Rusty99]

Hi Gents,
I picked up a used Stihl MS 261c this evening from Kijiji (Canadian version of Craigs list).

The saw starts up right away but needs some TLC. I need some input on how to get this saw back to tip top shape. The previous owner didn't even know it had air filter! I asked him how clean the filter was and he told me "it doesn't have one". I just shook my head.
So first on the list is buy a new air filter.

1. How can I clean the inside of the combustion chamber? It dark and oily looking or do I not need to be concerned?

2. The used spark plug is very oily and dark black. Is the saw in need of adjustment? Running too rich?

I've attached some pictures of what I'm describing. Would love to clean this saw up and keep it for many years to come. What else should I be checking/replacing/cleaning?

Cheers
Rusty[/ATTACH]

 

[VinceGU05]

is it a C or a CM? if its a CM i would dump the fuel and make a new batch at 40:1 run for for a few minutes.. once nice and cold, fresh plug and recalibrate it. then go cut some wood with it. after a tank check plug.

if its just a C model then you'll have to tune it your self. its either running rich or 20:1 mix.

 

[cgraham1]

Im pretty sure that's an M-Tronic saw. The carbureted ones don't have the C on the recoil...


I would put a new plug in it, clean the air filter, and run some new fuel through it @ 40:1.

 

[smokey7]

Hell show that in the oil threads and guys would trip. Run some yamaha ring free with oil of coarse in it for a tank or 2 running it pretty hard, with a new plug then check it out

 

[rd35]

Hey Rusty
If it were my saw I would get that nasty air filter pulled off of there and put on a new one. Then I would dump out the gas and fill it with new high octane 50:1 mix using a good synthetic mix oil from Stihl, Husky, or Echo. With it being an M-tronic, you should not need to do anything else besides run it. The oily cylinder is likely a result of the clogged air filter making it run very rich (even though that is not supposed to happen, I think it does with a badly clogged filter)
You won't need to clean the cylinder as it will, very quickly, clean itself up when you run it hard for awhile.

 

[pioneerguy600]

A little Sea Foam in the mix will clean it up quickly, just a capfull per tank and that cylinder will be shiny bright in 3 - 4 tanks.

 

[Rusty99]

How can I be sure it has the M-Tronic technology on this saw? It just says 261C on the recoil cover. As cgraham1 mentioned his saw is carbureted and just says 261.

I also wanted to double check that a NGK BPMR 7A is the correct replacement plug for this saw? I just did a quick goggle and found this specs sheet showing the plug

http://www.kwf-online.de/deutsch/pruef/pruefergebnisse/aagw/motorsaegen/6909_14e.pdf

 

[Hinerman]

A little Sea Foam in the mix will clean it up quickly, just a capfull per tank and that cylinder will be shiny bright in 3 - 4 tanks.

^^^^^^^this for sure.

 

[cgraham1]

The adjustable carb will have adjuster screws.

M-Tronic...


Regular carb...

 

[Philip Wheelock]

...What else should I be checking/replacing/cleaning?

Decompression valve (2 o'clock from the spark plug) looks to be busted. Saves wear & tear on the starter cord. The master control lever on an M-Tronic MS261 has 3 stops instead of 4, among other things.

 

[Miles86]

Hey-

Nice saw, I would make sure the fins are cleaned well, and new spark plug, new air filter, and check flywheel and coil for excess gunk. New fuel lines and filter and tank vent, since the PO didn't do any maintenance.
Try a dose of gumout all-in-one in your premix , it really does work to clean out the combustion chamber, and frees up the rings, need to use it for a while, not just one dose..

 

[blsnelling]

You can clearly see the electronics on the carb. It's a MS261C, which is MTronic.

 

[VinceGU05]

Try using a phone with poor eye sight compared to a 24" monitor.

 

[AKDoug]

That is an M-tronic saw, nothing you can adjust. That filter is fine. They come new in the black color, no need to replace it. Just blow out with air. The cylinder is oily black because of crappy oil, nothing more. Take compressed air and blow off the saw. Otherwise, it looks like it's in good condition. I would pull the muffler off and check the piston really quick. Those little pluggy deals covering the bolt holes on the muffler pop right out with a knife.

 

[Andyshine77]

Like Brad said you can see electronics on the carb, it's an Mtronic model. Pics can make things look worse, but from what I can see it looks nasty inside that cylinder. It doesn't take much to pull the cylinder off the 261, I'd take the cylinder off and clean her up properly myself. Looks like they used SEA 30 for mix.

 

[Rusty99]

Thanks for the input so far guys! I should have a progress update for you after work with some pictures. Planning to use some Sea Foam on the first couple of tanks and see how it cleans up, Sea Foam is a great idea that I never would have thought of on my own, love this site! . If it is still looking grungy I might have to pull the cylinder off as Andyshine77 mentioned.

 

[Rusty99]

Got the saw all cleaned up but noticed that the chain had a very distinct blue/black color to it. I gave the chain a quick spray and scrub with purple power. I'm wondering if this blue/black color is from the previous owner overheating the bar & chain by running no oil, low oil or poor quality bar oil? I dumped the bar oil and it was a bright honey yellow color. The oiler seems to be working fine, I took the bar off and revved the throttle to make it dispense oil. Any thoughts? Should I be looking into a new chain?

 

[blsnelling]

Dress the bar, sharpen the chain, and run it.

 

[Rusty99]

Dress the bar, sharpen the chain, and run it.

Can you give me any insight as to what causes the blue/black burned look on the chain? Is this normal wear or from something else?

 

[sunfish]

Hopefully the price was cheap?