Stihl MS361 project saw has me stumped

[The Shooters Apprentice]

Few years ago I found most of a Stihl MS361 in the dump. It was missing everything from cylinder back on the intake side, including the cover, no bar, and looked very well used.

It sat in the shed for about a year and I finally got around to finding a parts diagram and figuring out what I needed. Ordered all the parts from Farmertec, and went to go put it together and decided maybe I should check the piston and compression. Popped the muffler and the rings were broke, piston and jug toast. It sat for another year until I ordered a Farmertec Big bore kit for it, mildly ported it, and got it all together just to find it didn't have any spark. Sat again until I got the new coil, and then I finally got to run it. Now the issue I was having is that it won't run on a full tank of gas. It will start and run for 30 seconds or so, then act like it’s running out of gas. Crack the cap, and it will fire and run but leak gas from the cap. Once it gets down to under 3/4 tank or so it will run pretty good. I replaced the tank vent and same thing. So its been sitting for about 6 months now and I decided today that I want to go ahead and get it running right, but I'm not sure where to begin looking to fix this problem.

Any Ideas?

 

[The Shooters Apprentice]

Some how I posted this without actually explaining the problem I’m having with the saw. Edited

 

[user 122190]

Sounds to me like you have some venting issues. Even though you replaced some pieces you need to go further. Solvents, pokers, high pressure air to free up the restrictions and/or blockage.

 

[link]

No relations but here's a story; I got a 025 from a neighbor and he wanted me to fix it running...
Well I looked at it and I said yes though it was an expense project on my behalf.
I took it apart completely and cleaned every part with a toothbrush and a dishwasher and I replaced all rubber parts with new (aftermarket of course - he was not looking to invest heavy money in to this old saw yes?
Crank seals and carb boot and gasket all new and still it showed signs of an air leak; wouldn't run properly at idle, needed abnormal amount of fuel mix.

I was absolutely transfixed - I had done everything...
I posted a thread in here and asked and the respond I got was that if I did not use OEM parts they would not give me advice
In a last desperate attempt I pulled the carb and I added silicone gasket sealant at both sides of the new carb gasket.

Now it runs perfect.
And with the work I did to it, it will likely do so for another 15-20 years...

 

[The Shooters Apprentice]

No relations but here's a story; I got a 025 from a neighbor and he wanted me to fix it running...
Well I looked at it and I said yes though it was an expense project on my behalf.
I took it apart completely and cleaned every part with a toothbrush and a dishwasher and I replaced all rubber parts with new (aftermarket of course - he was not looking to invest heavy money in to this old saw yes?
Crank seals and carb boot and gasket all new and still it showed signs of an air leak; wouldn't run properly at idle, needed abnormal amount of fuel mix.

I was absolutely transfixed - I had done everything...
I posted a thread in here and asked and the respond I got was that if I did not use OEM parts they would not give me advice
In a last desperate attempt I pulled the carb and I added silicone gasket sealant at both sides of the new carb gasket.

Now it runs perfect.
And with the work I did to it, it will likely do so for another 15-20 years...

I don't think farmertec gets the credit they deserve getting parts to us hobbyist. They don't actually manufacture anything, just a parts warehouse. Last time I ordered a recoil from them I got one with OEM markings on it. I'm also gotten parts from Italy and Germany from them, so not all Chinese "crap".

 

[The Shooters Apprentice]

I'm about ready to throw this saw back in the dump. I put all new fuel lines on it when I rebuilt it, but went ahead and blew them all out today, and behind the tank vent, new fuel filter, and cleaned the carb. Same thing. I decided maybe I should change the fuel cap on the off chance that it also vents through the cap, and success, saw fired right up and ran great. Take it out to the wood pile and start going to town, cut up a few logs to get it warm, and it sounds like its running a bit lean, so I grab a screw driver and back the high out a bit, get half way through the next cut, let up on the throttle, and bam it dies. Now I can't get the stupid thing to do anything other then sputter.

 

[Bubster]

Metering valve need some attention possibly?

 

[The Shooters Apprentice]

Metering valve need some attention possibly?

My next step will probably be to order a OEM carb and see what happens with that. Im pretty sure the carb on it came from Amazon.

 

[John Lyngdal]

I'm about ready to throw this saw back in the dump. I put all new fuel lines on it when I rebuilt it, but went ahead and blew them all out today, and behind the tank vent, new fuel filter, and cleaned the carb. Same thing. I decided maybe I should change the fuel cap on the off chance that it also vents through the cap, and success, saw fired right up and ran great. Take it out to the wood pile and start going to town, cut up a few logs to get it warm, and it sounds like its running a bit lean, so I grab a screw driver and back the high out a bit, get half way through the next cut, let up on the throttle, and bam it dies. Now I can't get the stupid thing to do anything other then sputter.

I'm a total fan of the MS361 and the one I have cuts above its displacement.
John's dump is always accepting MS361 which includes free haul away services should the need arise.

 

[a. palmer jr.]

Yeah, I've not had much trouble with mine other than the impulse hose came loose once I guess because it was old and the suspension is rather soft. I just stuck it back on..

 

[The Shooters Apprentice]

I'm a total fan of the MS361 and the one I have cuts above its displacement.
John's dump is always accepting MS361 which includes free haul away services should the need arise.

When this one runs, it is very impressive, but so far I haven’t been able to put more then half a tank through it at a time.

 

[a. palmer jr.]

It may have been mentioned but you might check/replace the tank vent.

 

[The Shooters Apprentice]

It may have been mentioned but you might check/replace the tank vent.

It’s been replaced.

 

[PV Hiker]

Is the fuel filter sitting in the tank properly on the bottom or catching or twisting causing it to be hung up half way?

To add is there a slit in the fuel hose half way up from bottom?

 

[HumBurner]

I'm about ready to throw this saw back in the dump. I put all new fuel lines on it when I rebuilt it, but went ahead and blew them all out today, and behind the tank vent, new fuel filter, and cleaned the carb. Same thing. I decided maybe I should change the fuel cap on the off chance that it also vents through the cap, and success, saw fired right up and ran great. Take it out to the wood pile and start going to town, cut up a few logs to get it warm, and it sounds like its running a bit lean, so I grab a screw driver and back the high out a bit, get half way through the next cut, let up on the throttle, and bam it dies. Now I can't get the stupid thing to do anything other then sputter.

Do the gas caps on those have built in vents like on the 0-series? Does the cap seat correctly? Rubber ring in good shape?

 

[The Shooters Apprentice]

Do the gas caps on those have built in vents like on the 0-series? Does the cap seat correctly? Rubber ring in good shape?

I put new caps on it and it ran ok for about a half a tank.

 

[icontreeservice]

I’ve had mixed luck with amazon carbs... if it is a China one you’ve got maybe the oem will fix it. The adjustment screws on Chinese carbs are sometimes oddly shaped compared to oem, and I’m sure that’s not the only difference.

 

[PV Hiker]

Is the fuel filter sitting in the tank properly on the bottom or catching or twisting causing it to be hung up half way?

To add is there a slit in the fuel hose half way up from bottom?

@The Shooters Apprentice Any answer? I had a filter sit up high and cut out.

 

[The Shooters Apprentice]

@The Shooters Apprentice Any answer? I had a filter sit up high and cut out.

Fuel filter is proper. I topped the tank off last time I was messing with it to be sure that wasn’t it. Haven’t messed with it since then.

 

[PV Hiker]

Thanks, Just checking.
Patrick