Trouble with two MS360s

[Kevin White]

Hi Guys, Im fresh from Another Site and liking the forum. I do alot of buy, sell, repair and Im quite confident in my chainsaw repair abilities, but I have 2 saws here that have stumped me and I need your help.

I bought 2 Stihl ms360s from a guy and Im having trouble with both. The guy told me that he bought these saws to fix up for himself, but never got around to it. Thats all the history I know. They are both in decent shape with typical wear and tear but not commercial wear. Ill tell you what I have done and let me know what you think.

Saw1 . The guy told me this one sounded weird whenever you pulled the cord. I tore down the cylinder and checked around didnt see anything weird, a little transfer but nothing crazy. I grabbed the crank and pushed up and down, no movement. Didnt see any wear marks on the crankcase and didnt look like anything was hitting. I moved on with the repair and did the fuel line, filter, and kit. The saw starts up, runs and cuts, but sounds like a clanking noise. I have repaired over 100 saws and never heard this noise before. It sounds close to the flywheel but I have removed the flywheel and key to check around for any hitting, but sounds internal. You can hear it a little when you pull the cord, but as it idles, its definetly and knocking noise. I replaced the piston and cylinder with one from the other saw, just to eliminate something, and sounds the same.

Saw2: I did the fuel line, filter, and kit right away. Saw starts up on choke, idles well on high idle, then once I blip the throttle it will start to starve. I can make adjustments with the L needle but seems inconsistent. I took the carburetor from the other saw(it would idle and run consistant so I figured the carb was good) and installed it on this one, and got the same results. To me it seems like an air leak, but Im having trouble pinning it down. I have not done a leak down test on the crankcase. How else could I know if it was seals? Maybe some carb spray?

Sorry for the long post and any help would be appreciated.

 

[Whiskers]

If you work on a lot of saws learning to do pressure/vac testing is invaluable. It is the only way to pinpoint air leaks that would otherwise be nearly impossible to find.

 

[calebng15]

+1 on the Pressure/pac gauge! Sometimes it aggravates me trying to make sure everything is sealed up, but I know it is really saving me from a lot of trouble.

Also, are you bearings any good? On saw #1?

 

[trooney]

That would be my guess on saw #1. Sounds like it to me. I agree with the other posters on the pressure/vac test. Thats the first thing i do to a saw to make sure I have a tight crankcase before I jump into everything else. Saves alot of time and effort. If you don't have anything to do a pressure/vac test spray starting fluid by the intake boot, impulse line, base of cylinder, and both seals (with it running). If you have an air leak it might stall the saw. But nothing takes the place of a real test.

 

[trooney]

Or lower the rpm's significantly

 

[Lone Wolf]

Saw 1 bearing noise from the crank support bearings
Saw 2 vac leak.
Rip them both down 100 percent check everything and replace whats worn
Then buy a vac and pressure tester combined make some block off plates and make sure they are both holding pressure and vac.
dont forget new seals and gaskets.

 

[Milkman31]

This kit will save you lots of trouble and time when work on saws.

 

[Jughead]

like lone wolf says.plastic cage bearings suck.about every 026 i get has disappearing bearing cage syndrome.bearing may feel good turning the crank by hand but at 3k rpm its a different story.when the balls get to bouncing around it gets serious fast.

 

[Lone Wolf]

like lone wolf says.plastic cage bearings suck.about every 026 i get has disappearing bearing cage syndrome.bearing may feel good turning the crank by hand but at 3k rpm its a different story.when the balls get to bouncing around it gets serious fast.

Hah hah!

 

[czar800]

Saw #1 have a look at the clutch also...

Saw#2 Air leak.... I love my Mityvac!!

 

[czar800]

Almost forgot, Welcome aboard!

 

[Kevin White]

This kit will save you lots of trouble and time when work on saws.View attachment 22992

I have this kit, but use it for the lines and carb. I guess I need to fabricate a block off plate? Ill look up a couple past threads about the crankcase tests. Thank you for l the posts. I will move forward as suggested and keep updating. Thank you

 

[huskihl]

A piece of gorilla tape or strip of inner tube rubber between the carb/boot and the muffler/cylinder seals them off to do a p/v test.

Since you had the cylinder off saw 1 did you check the rod bearing?

 

[Kevin White]

A piece of gorilla tape or strip of inner tube rubber between the carb/boot and the muffler/cylinder seals them off to do a p/v test.

Since you had the cylinder off saw 1 did you check the rod bearing?

Once it's blocked off, where do you put the mityvac hose?

I grabbed the crank shaft and checked for play. Is that the best way to do that?

 

[mdavlee]

Once it's blocked off, where do you put the mityvac hose?

I grabbed the crank shaft and checked for play. Is that the best way to do that?

Impulse

 

[huskihl]

Once it's blocked off, where do you put the mityvac hose?

I grabbed the crank shaft and checked for play. Is that the best way to do that?

I picked up a spark plug adapter from fordf150. He has tapered rubber strips for block-offs to use also

 

[huskihl]

Or like Mike said, disconnect the impulse from the case and hook up to the barb

 

[Milkman31]

Once it's blocked off, where do you put the mityvac hose?

I grabbed the crank shaft and checked for play. Is that the best way to do that?

I made this from some old scraps laying around the shop. All you have to do now is block off the carb and exhaust screw this in and your good to go.

 

[czar800]

I used a old compression tester.

 

[Kevin White]

Awesome ideas. Thanks. I'm liking this forum alot.