New to me ms361 - "while I'm in there"

[jrobie79]

Someone suggested I take a look at this forum vs other chainsaw forums, and so far I've been impressed... I've beeen reading a bunch and just picked up a new to me ms361, it is absolutely filthy, so far I've probably picked off, wiped, scraped about a full pound of crap. So i started stripping it to clean it. See below:

Before I started tearing it apart I took a compression reading, and got just under 120psi. Is this acceptable? Haven't run the saw at all so I never took a warm reading:

My question is, what should I change while I'm in the process of putting everything back together since it'll be most stripped down? When I work on my car if I have to take a bunch of parts off I might as well swap in new smaller parts (hoses, plastic bits, etc...). I was thinking maybe some seals, rubber bushings, hoses, etc.

I've been using the factory service manual and this forum to take it apart and look forward to my new addiction and bring more active on this forum.
Does this piston look toast? If so, should I go with a genuine Stihl replacement? or any recomended aftermarket? (I've read meteor piston with caber rings?)

I also noticed there is side to side play in the rod at the crankshaft (shown in photos below), is this normal?

Should I use upgraded (ceramic) bearings? Also, in the IPL it lists two size cylinder gaskets, what's the deal behind one or the other?

Took a few other photos of the clutch side, lot of worn out powdercoating, so I'm gonna split the case and see what I can do to get it re-powdercoated (anyone recomend somewhere to get this done?)

 

[Dub11]

Welcome and @Glock37 does really good powered work. And if it spins or seals replace it. And I see no cylinder pic.

 

[jrobie79]

Welcome and @Glock37 does really good powered work. And if it spins or seals replace it. And I see no cylinder pic.

Meant to say piston. I'll grab some pictures of the cylinder tomorrow, must have left those ones on my work computer

 

[Dub11]

Meant to say piston. I'll grab some pictures of the cylinder tomorrow, must have left those ones on my work computer

Got ya a meteor piston would be the only AM thing I would trust inside. When it comes to deals and fuel lines and bearings either oem or name brand.

 

[CR888]

If porting is something you have yet to master, I'd start with the easy stuff that will net small results here & there which will far exceed a poor port job. Port match exhaust gasket/muffler to shape of exhaust port. Remove any casting flash on piston (2 holes beside gudgeon pin). Dial in the timing advance/retard for best performance. Put a set of caber rings in to get compression where it should be 155-180psi (I'd use that piston after inspection/cleanup. New fuel filter, lines & impulse, clean spark arrester screen. Clean carbon from piston and tidy it up. Clean out exhaust port. Mild muffler mod to increase flow but still stay not too noisy. New spark plug & clean up any rust on coil. Set flywheel to coil gap. Clean carb put new kit in and tune when together. There's a few easy to do ideas/mods to get a strong running saw you can certainly go much further but these little things won't cost much and are easy. Oh...& forget the ceramic bearings!

 

[jrobie79]

If porting is something you have yet to master, I'd start with the easy stuff that will net small results here & there which will far exceed a poor port job. Port match exhaust gasket/muffler to shape of exhaust port. Remove any casting flash on piston (2 holes beside gudgeon pin). Dial in the timing advance/retard for best performance. Put a set of caber rings in to get compression where it should be 155-180psi (I'd use that piston after inspection/cleanup. New fuel filter, lines & impulse, clean spark arrester screen. Clean carbon from piston and tidy it up. Clean out exhaust port. Mild muffler mod to increase flow but still stay not too noisy. New spark plug & clean up any rust on coil. Set flywheel to coil gap. Clean carb put new kit in and tune when together. There's a few easy to do ideas/mods to get a strong running saw you can certainly go much further but these little things won't cost much and are easy.

I got pictures of the cylinder uploaded below. I'm gonna throw it in an ultrasonic cleaner to make sure its clean before reassembly. I have zero experience porting or any type of internal machining/shaping, so I'll probably avoid that right now. Also this is my first chainsaw 'rebuild'. So I'm unfamiliar with dialing in the timing, I have swapped engines on a few of my cars, so I'm mechanically inclined, I just don't want to mess anything up in regards to porting/machining.

In regards to the piston, I tried to get some closer shots, it looks like the exterior finish is 'scratched' away in some locations, the photos below might explain it a little better.

 

[Dub11]

http://www.hlsproparts.com/Meteor-Stihl-MS341-MS361-piston-assembly-p/pc1884.htm

Just get one of these they will come with cabers.

And if it was me I'd plug off or get a brand new decompression valve.

 

[blsnelling]

Your crank is normal. Make sure there is NO transferred aluminum on the cylinder bore.

 

[huskyboy]

Someone suggested I take a look at this forum vs other chainsaw forums, and so far I've been impressed... I've beeen reading a bunch and just picked up a new to me ms361, it is absolutely filthy, so far I've probably picked off, wiped, scraped about a full pound of crap. So i started stripping it to clean it. See below:

Before I started tearing it apart I took a compression reading, and got just under 120psi. Is this acceptable? Haven't run the saw at all so I never took a warm reading:

My question is, what should I change while I'm in the process of putting everything back together since it'll be most stripped down? When I work on my car if I have to take a bunch of parts off I might as well swap in new smaller parts (hoses, plastic bits, etc...). I was thinking maybe some seals, rubber bushings, hoses, etc.

I've been using the factory service manual and this forum to take it apart and look forward to my new addiction and bring more active on this forum.
Does this piston look toast? If so, should I go with a genuine Stihl replacement? or any recomended aftermarket? (I've read meteor piston with caber rings?)

I also noticed there is side to side play in the rod at the crankshaft (shown in photos below), is this normal?

Should I use upgraded (ceramic) bearings? Also, in the IPL it lists two size cylinder gaskets, what's the deal behind one or the other?

Took a few other photos of the clutch side, lot of worn out powdercoating, so I'm gonna split the case and see what I can do to get it re-powdercoated (anyone recomend somewhere to get this done?)

Side/side play is normal in rod bearing. You don’t want up and down.

 

[AlfA01]

Nice saw. Hope to see it running soon.

Rod end play is measured as I've drawn kind of poorly in the photo. Not side-to-side as you've indicated. Hold near the base of the crank rod and apply forward and backward force. Notice if there is any movement.

Replace the crank seals so you don't get an airleak in the future around the crank.

 

[jrobie79]

Awesome thanks a ton guys. I'm gonna put together a parts list for my dealer (I'm assuming the seals and clutch side bearing should be genuine Stihl? slacker or SKF should be fine for the flywheel bearing from what I've been reading correct?)

 

[brandonstclair20]

I think i see a problem with the roof of the exhaust port (right beside the red arrow) . I think the cylinder is done. The tecomec parts I have bought/ used look great and seem to work well. I would use oem clip tho.

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[jrobie79]

I think i see a problem with the roof of the exhaust port (right beside the red arrow) . I think the cylinder is done. The tecomec parts I have bought/ used look great and seem to work well. I would use oem clip tho.
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I'll clean the cylinder out tonight and try to get a better picture, I think it's just dirty and that shiny part is a void in the grime

 

[Stump Shot]

Welcome to OPE. The things I would replace on a well used MS361 would be the crank seals, intake boot, impulse line, fuel line and filter, air filter and spark plug. Now that piston you have there is done, you really need to find and correct what made that happen in the cylinder. If your eyes can't find it sometimes your finger can, anything no matter how minuscule must be dealt with. Things to check, AV's if worn can cause premature failure in the intake boot. The flywheel, check for the built in key to make sure it's not "rolling" its way out. Like on any saw the clutch, drum, bearing and sprocket should be checked. The crank bearings should be looked at very carefully if any doubt, throw 'em out. When you replace your piston a new OEM wrist pin bearing should be installed with it. Now is also the time to clean the exhaust port of all carbon.
These were/are very good performing saws as they were from the factory, if modifying anything I would start with the muffler first. This can be quite the chore on this model. Not sure if an AM muffler is an empty can or not, but would be worth looking into.

 

[drf256]

Use any good quality bearing for the Flywheel side. Should be 6202.

Unfortunately, the AM muffs also have the annoying baffling inside. I now cut the Fly side rear corner off, mod/remove the baffle, and weld it back on. Just faster.

Take a look at that exhaust roof. Brandon has a good point. If it’s damaged, it may still be fine for porting. Let us know.

 

[trooney]

Without looking at the IPL, those two base gaskets are probably .5mm and 1mm. Its your call which one you go with, I personally would use the .5mm one.

 

[jrobie79]

I think i see a problem with the roof of the exhaust port (right beside the red arrow) . I think the cylinder is done.

Take a look at that exhaust roof. Brandon has a good point. If it’s damaged, it may still be fine for porting. Let us know.

I quickly cleaned it, looked like it was just baked on grime, and not a gouge or anything compromising. After I run it through the ultrasonic cleaner I'll have a better idea

 

[Frank bierce]

Looks like the cylinder will need just a little bit of clean up, but looks pretty good.
Like others have stated...a good meteor piston, caber rings...if you are planning on splitting the cases...new quality bearings/seals/fuel lines, etc. , would all be a great idea.

 

[Dub11]

Any updates?

 

[jrobie79]

Any updates?

nothing yet, been busy getting my summer car running and work has been extremely busy. I have it almost all stripped down, gonna split the case hopefully this weekend. I started assembling my parts list and hopefully I'll have the case ready for powdercoat by the end of the weekend.