MS361 seal replacement

[yawning_dog]

Hi folks, I was hoping someone could help me with an easy question. My MS361 is running terrible missing and with an erratic idle. At first I thought it was an electrical issue so I replaced the plug and coil but that didn't help. It's still racing like it's totally lean so I'm thinking it's got an air leak.

My question is whether you need to split the case to change both crank seals on a 361 or if you can pull them out after removing the clutch/flywheel? Thanks!

 

[James Sawyer]

Just check the seal depth before removing the old seals so the replacement isn't seated to deep. Pull the seals and cut a pop can sleeve to help slide the new seal over the crank. I have tool to remove seals like the Lisle 58430 (I have one a little different smaller), but there lots of different tools or ways to remove seals. I install the new seal with Loctite 620. If you think the seals are bad you might think about replacing the fuel line and impulse line as well. The PTO side is most likely the problem side.

 

[PV Hiker]

@yawning_dog check you inbox for IPL and manual.

 

[yawning_dog]

Thanks very much for your replies, PV Hiker and James Sawyer! Thanks for the tips about the impulse and fuel line. The bizaar thing about this saw is that it's been known to run the chain backwards occasionally. Assuming it's not possessed, I'm thinking about maybe replacing the flywheed next. Maybe it is possessed.

 

[James Sawyer]

I believe those flywheels OEM are like $120... probably not the flywheel check the keyway/ timing.

 

[yawning_dog]

Yikes. I woud probably explore an aftermarket just to see if it fixed it. It has one of those integrated keys but it still seemed to be intact and seated well within the crank "slot". I'm not sure what else could go wrong with the electical side of things unless one of the two wires from the coil is occasionally shorting or open. I haven't replaced those yet.

 

[SteveSr]

...unless one of the two wires from the coil is occasionally shorting or open. I haven't replaced those yet.

Is this an M-tronic saw? Whole new can of worms?

 

[Vintage Engine Repairs]

You can waste hundreds of dollars replacing parts unnecessarily if you aren’t going to diagnose an issue. If that’s the way you’re going to proceed, take it to a shop. It’s cheaper, quicker, less frustrating and you won’t break anything in the process. You need to be prepared to invest in some tools, in your case a good start is a timing light, inline spark tester and a pressure and vac tester.

 

[Woodslasher]

I had a real B-word of a 361, turns out the issue was a partially unscrewed coil wire. Sometimes it would contact, sometimes it wouldn't. Once I cinched it down it the saw ran much better.

 

[ZeroJunk]

Don't think Mtronic started until the 362's .
If it is racing at idle there is a leak somewhere. Exception to that is I have worked on saws that had sticking linkage issues, and even sticking butterfly issues, or sometimes tinkerers just screw the idle screw in too far.
No need to split the case to replace seals.

 

[stihltech]

Wheres my Magic Wand. Oh here it it. It's called diagnosis.

 

[ZeroJunk]

My saw is cutting sideways, do I need to do a pressure vacuum test ?

 

[lone wolf]

My saw is cutting sideways, do I need to do a pressure vacuum test ?

You need a straight edge and a level.

 

[ZeroJunk]

You need a straight edge and a level.

Will a plumb bob work ?

 

[lone wolf]

Will a plumb bob work ?

I suppose if applied correctly it could.

 

[stihltech]

Just move your hand over on the handle bar a little and push harder.

 

[SteveSr]

Don't think Mtronic started until the 362's .

Well, the OP said 2-wires and I believe that the M-tronic coils have 2 small low voltage wires and the spark plug wire.

 

[a. palmer jr.]

Just move your hand over on the handle bar a little and push harder.

I know a fellow that used his knee to push up on a bar while bucking up a log..didn't work too well for him..

 

[yawning_dog]

Hi again, thanks for all the replies. No, mine isn't an M-tronic. It's a pretty basic setup like my 036. To Vintage Engine Repairs, yeah, I know randomly replacing parts isn't the best way to go but I really thought it was going to be an electrical issue with it sounding like it was missing and occasionally running backwards. I figured a cheap coil would be a simple fix... not to be. It alsmost seems like there's other things going on with it with the inconsistent idle but I haven't had a chance to tear into it more. I'll be sure to post what I find in case it might help someone in the future.

 

[ZeroJunk]

Hi again, thanks for all the replies. No, mine isn't an M-tronic. It's a pretty basic setup like my 036. To Vintage Engine Repairs, yeah, I know randomly replacing parts isn't the best way to go but I really thought it was going to be an electrical issue with it sounding like it was missing and occasionally running backwards. I figured a cheap coil would be a simple fix... not to be. It alsmost seems like there's other things going on with it with the inconsistent idle but I haven't had a chance to tear into it more. I'll be sure to post what I find in case it might help someone in the future.

I'm thinking a sort of modern saw with a new coil running backwards and you have checked the flywheel key you should bury it as deep as possible and put a very visible cross abve it.