Problems Stihl MS261CM

[SpaceBus]

Here's a thread that might be useful: https://opeforum.com/threads/interesting-find-troubleshooting-ms261-c-m-hard-start-issue.24517/

 

[tadmaz]

I've heard about the solenoid stuff before. I guess I will get the kit with the white solenoid and orange filter. I crushed my index finger and I could use a little project while I heal up.

 

[3fordasho]

Purchased a new 661C in 2015 with an early version of mtronic with the white fuel solinoid. Probable not even 2 hrs of use and the thing would not restart hot in short order (of course out of warranty) I just replaced all the mtronic components with version 3 mtronic, the kit includes the improved black fuel solinoid, orange fuel filter/pickup, and new coil/control module. Just over $100 and so far so good. Part number for the kit is 1144 007 1801. There is some youtube videos detailing replacement of all three items, not too difficult and took about an hour. I did need a t-10 torx bit with the hole (tamperproof).

 

[tadmaz]

I think you're mixing up the solenoid colors. Black solenoid/white filter bad. White solenoid/orange filter good. Specifically for the MS261, no coil/control module needed. Part# 1140 007 1802

 

[3fordasho]

I think you're mixing up the solenoid colors. Black solenoid/white filter bad. White solenoid/orange filter good. Specifically for the MS261, no coil/control module needed. Part# 1140 007 1802

You are correct sir. And now it's too late to edit. Black solinoid= bad, white solinoid = new and improved.
white filter= first version, orange filter= better filtration.

 

[tadmaz]

I had to convince the stihl guy at my ace hardware to order the exact part# I wanted. Got the kit. My MS261 was made in 02/18 and it had the black solenoid and white filter. I was able to replace the solenoid without removing the carb or anything, just a little tricky getting the clip and small screw back in. Runs great. May be a while before I run the saw in hot conditions to see how it does.

 

[Sodbuster]

Not sure if this would cause a difference, but on my MS261, there is a winter and summer orange tab under the cover, in the winter position it directs some heat from the engine to keep the carb from icing up. In the summer position that hole is closed, simply slides in and out with a screwdriver.

 

[tadmaz]

@Sodbuster did you check which color solenoid and fuel filter you've got? You are the OP

 

[Sodbuster]

Black solenoid, white filter. Mine is definitely not a version 3. It was purchased 11/2/2017

 

[Woody5506]

Sodbuster, I'm not a huge gear head but I have the same saw and my assumption is once you ran the thing dry from the old fuel, it becomes a bit tougher to get going again on a refill. Why this is, I do not know, but I've gotten used to it and try not to run the fuel dry for that reason. Everytime I do, it does what you described. Start up hard, then putter for a bit, give it throttle and it dies out or really bogs down. I basically let it idle for a bit and start feathering the throttle and its fine from there.

 

[tadmaz]

Sodbuster, I'm not a huge gear head but I have the same saw and my assumption is once you ran the thing dry from the old fuel, it becomes a bit tougher to get going again on a refill. Why this is, I do not know, but I've gotten used to it and try not to run the fuel dry for that reason. Everytime I do, it does what you described. Start up hard, then putter for a bit, give it throttle and it dies out or really bogs down. I basically let it idle for a bit and start feathering the throttle and its fine from there.

Do you have the black solenoid? If so, get the white one and let us know if it helps. Black one is known to stay open (flood) when you turn the saw off.

 

[Sodbuster]

Thanks Woody and Taz, I have the white solenoid. It sat for a year drained of fuel, after I shattered my wrist. Ran a couple of tanks of 90 octane, off road fuel and Stihl Platinum oil and some Sea-foam, and now it runs like a banshee, and starts great.

 

[Sodbuster]

Thanks Woody and Taz, I have the white solenoid. It sat for a year drained of fuel, after I shattered my wrist. Ran a couple of tanks of 90 octane, off road fuel and Stihl Platinum oil and some Sea-foam, and now it runs like a banshee, and starts great.

And correction to Tadmaz, I previously quoted it was black, when it is definitely white.

 

[Sodbuster]

Thanks for doing the math, didn't realize it was such a trivial amount. I run everything on 40:1 and tune the saws accordingly.


As far as the OP's 261, it does sound like the computer needs to learn the saw again after it sat for several months.

You are correct, the more I run it the stronger it gets. Was cutting some 16" dead Ash today, and it just keeps pulling harder and harder, throwing chips like crazy.

 

[SpaceBus]

You are correct, the more I run it the stronger it gets. Was cutting some 16" dead Ash today, and it just keeps pulling harder and harder, throwing chips like crazy.

It's a pretty slick system. Any future saw purchases will be fuel injected/auto tuned or electric.

 

[Woody5506]

Do you have the black solenoid? If so, get the white one and let us know if it helps. Black one is known to stay open (flood) when you turn the saw off.

Mine doesn't flood. But, just like my small 211, when you run it out of gas, it just acts like it takes some coaxing to get the gas flowin'

 

[tadmaz]

I had a large white oak fall this morning. It was leaning 45 degrees for many years, amazing it lasted this long. 84F outside, saw died after a 1/2 tank of gas. Got it started with full throttle start and finished what I wanted to do. Would not normally start at all. Too hot to cut for too long anyways. But not very good for a pro saw with a $50 "fixed" solenoid and fuel filter. Oh well.

 

[tadmaz]

75F today, cut up the white oak. 2 tanks (pints) of gas. No problems, but with that temp I never had problems with the white solenoid.