MS361

[a. palmer jr.]

Just re-posting this from the "what's on your bench" thread. This 361 is very hard to turn over, meaning it has great compression but it doesn't have the right feel to it, like it has compression while the piston is going up or down. I've had saws like this before and the crankcase was full of fuel or bar oil but I've had this one upside down with the spark plug out for a few days and nothing comes out. Wondering what else to look for..

I have another 361 that I've rebuilt and it doesn't have the same feel when pulling the starter.

 

[Wood Doctor]

I have a Stihl MS 661C M-tronic with the same difficulty that I could rebuild, but I have not done that because the parts are so expensive that I decided to part it out for repairs to others. This beat up 661 is so hard to turn over that I cannot even measure the compression. I figured it could easily take a complete rebuild with so many expensive parts that it was not worth it.

Your other 361 that you rebuilt sounds like it's in great shape. Since 361 parts are out there and reasonably priced, I would say to go ahead and give this one a try the same as you rebuilt the other one. It could be just the crank seals and/or bearings or shot as well, but I seldom if ever have to replace these on a 361.

 

[a. palmer jr.]

Part of the problem with this saw is that it's not mine and I need to find out how much the owner wants to pay to get this one going. I don't think it's been apart before so I might be able to find out something just by removing the jug and see what's going on with the crank and bearings. You know, I think I have a spare piston and cylinder kit in the garage...

 

[a. palmer jr.]

I just got back from the garage and did find a new piston/cylinder kit for the 361 along with a spare set of rings. I did a little bit of pressure testing on it while I was there and found no leaks other than with my equipment. I guess while I have it down this far I might as well take it apart and see what I can find.
I plugged up the compression release hole and I can't pull it hard enough to get a comp. reading on this one either. After going through all this I'm still wondering if it didn't just need an ignition module...

 

[huskihl]

Recoil pulley might be binding

 

[a. palmer jr.]

Recoil pulley might be binding

It does make a little squeaking noise. It seems to pull over good when the sparkplug is out though.

 

[huskihl]

It does make a little squeaking noise. It seems to pull over good when the sparkplug is out though.

Sure. But it could be binding under load

 

[a. palmer jr.]

Sure. But it could be binding under load

I'll take a look at it after the 4th. It certainly has a load! Very hard to pull. Maybe soon my new compression release will get here.

 

[PV Hiker]

You have another 361 and you know the recoil works... 4 screws and can give it a go to know for sure.

 

[cookies]

crank bearings plastic bearing cages broken and gone i bet

 

[PV Hiker]

What did the owner say that happened for him to bring it to you. Did he give you some history to lead you down a path of possibilities?

Is the crank bent, bearings cage broken causing problems when you try to pull hard?

 

[a. palmer jr.]

What did the owner say that happened for him to bring it to you. Did he give you some history to lead you down a path of possibilities?

What did the owner say that happened for him to bring it to you. Did he give you some history to lead you down a path of possibilities?

Is the crank bent, bearings cage broken causing problems when you try to pull hard?

I was told that the owner was running it and it ran perfect, he shut it off and the next time he tried to use it, it wouldn't start. What I wasn't told was, how long it sat between uses and if the fuel had sat in it for all that time. It was empty of fuel and bar oil when I got it. It was taken to another shop first and for some reason they didn't fix it, instead they brought it to me. It pulls over smoothly when the spark plug is out. I thought maybe the carb inlet leaked fuel into the cylinder but so far none has come out. I may go ahead and tear it down and see what it looks like inside. I don't make a practice of taking parts off my good saws to do experiments on customers' saws. If the starter looks bad I may buy a new one for it but I really don't think that's the problem. Tomorrow is a work day so I'll get out there and tinker some more on it then...

Is the crank bent, bearings cage broken causing problems when you try to pull hard?

 

[a. palmer jr.]

Okay, had a few minutes so went out and did the pressure test on the 361 and it held around 7 lb pressure for a long time. While I was at it I also pressure tested the carburetor and it was okay also. My de-comp valve should be here in a day or two so I'll try it next.
It's gonna be close to 100 degrees for the next couple of days so I'm limiting my time in the shop to just a few minutes at a time. When it cools off I'll resume tearing the saw down..

 

[KASH]

I have the opposite problem my shop is part of a barn 78 degrees outside 56 inside I wear my long johns under my coveralls or I get chilled.
Kash

 

[LogSawyer74]

What diameter is the pull cord? I've had a few instances where the only pull cord I had on hand was the smaller diameter stuff (used on 024, 026, etc.). I noticed the smaller cord wraps up smaller in the recoil pulley (in effect changing the "gearing" on the effort it takes to pull it over). If your pull cord is wrapped up to the outer edge of the recoil pulley, then that's something to cross off the list....

 

[a. palmer jr.]

I have the opposite problem my shop is part of a barn 78 degrees outside 56 inside I wear my long johns under my coveralls or I get chilled.
Kash

I was in my garage a few minutes ago, just long enough to change a compression relief on my Husqvarna 353 and now I'm wringing wet. Humidity is right near 100..

 

[a. palmer jr.]

What diameter is the pull cord? I've had a few instances where the only pull cord I had on hand was the smaller diameter stuff (used on 024, 026, etc.). I noticed the smaller cord wraps up smaller in the recoil pulley (in effect changing the "gearing" on the effort it takes to pull it over). If your pull cord is wrapped up to the outer edge of the recoil pulley, then that's something to cross off the list....

I'll check that out but I may have some of the problem solved. I put a new compression relief on this saw yesterday and now it pulls much easier than it did with the other one. I have a feeling that both of the ones I changed out this week were carboned up. I ordered a bunch of parts for the customer 361 and if I don't need them all I'll use them eventually on mine.

 

[PV Hiker]

Not sure the compression relief valve is the main problem. I live at altitude so compression lowers here but only feel like I need to press the compression relief valve maybe once a year. Are you relying to start the chainsaw every time by pressing the compression relief valve?

We have a Stihl 290 that was having problems with high compression trying to start. It really needed a compression relief valve as drop start was the best way. I readjusted the coil gap, it was off. Gapped the spark plug 0.025" that is 0.005" so slightly wider. Opened up the carb and readjusted the metering height. Cleaned and lubed the starter assembly.

After that the starter cord pulled as it should and no kickback due to high compression issues.

Not sure if your 361 is having similar problems, just a thought....

Can't imagine working in a shop that is hot and at 100 percent humidity!!! Yuck!

 

[a. palmer jr.]

Not sure the compression relief valve is the main problem. I live at altitude so compression lowers here but only feel like I need to press the compression relief valve maybe once a year. Are you relying to start the chainsaw every time by pressing the compression relief valve?

We have a Stihl 290 that was having problems with high compression trying to start. It really needed a compression relief valve as drop start was the best way. I readjusted the coil gap, it was off. Gapped the spark plug 0.025" that is 0.005" so slightly wider. Opened up the carb and readjusted the metering height. Cleaned and lubed the starter assembly.

After that the starter cord pulled as it should and no kickback due to high compression issues.

Not sure if your 361 is having similar problems, just a thought....

Can't imagine working in a shop that is hot and at 100 percent humidity!!! Yuck!

Not usually that hot or humid, it rained today so the humidity is naturally high, temp now is actually around 80 but at the time I wrote that it was 97 outside and quite muggy.
As for compression, I'm near 80 years old and I use the de-comp every time I start the saws equipped with one, it saves my arm and also the starter assembly. I have the 361 apart right now, waiting on a few parts. I did find a busted fuel line on the saw so that's one problem for sure. The spark appeared very weak so I also ordered a module after trying several spark plugs and they all did the same thing. I'll let you know if I get it running and what all it needed..

 

[Dennisthemenace]

I don't think a decomp is ever necessary on a little saw like a 361. I'd be looking for something else