MS361 Idle Question

[StihlsawuserMS361]

I'm the original owner of a MS361,probably from 2009 or so. Saw has been used but not abused, primarily used for firewood bucking. Last year I noticed the curb idle would change, whereas I had to either increase or decrease idle speed, something I've never had to do previously. Always E Free fuel, Stihl Ultra oil. I'm thinking maybe an air leak. I'm smart enough to do a pressure/ vacuum test but haven't purchased the needed tools. I believe instead of messing with a saw that only had an oil pump replacement (my fault, leaving tape on the discharge hole while cleaning, causing the saw to over oil) since I've owned it, I'd prefer to have someone better skilled to say repair or reseal it.
Can anyone recommend a reputable shop somewhere near the 13905 NY area for this service? Or to ship it out maybe? What's left of the Stihl dealers locally aren't skilled enough to do much of anything. The saw still runs and cuts great, I'd rather address this before I have to.
Thanks to all.

 

[Wood Doctor]

Rather than an air leak, it might just need a new carburetor. It's a rather simple installation for an average mechanic. Worth fixing in my book, I have changed out several. Start with an AM carb (less than $20 on e-bay) and see if that solves the problem. If it does you can then feel better about spending three times that much on an OEM carb. Replacing this saw with a new one would set you back about $800 or so. Good Luck!

 

[StihlsawuserMS361]

Thanks Wood Dr.
I guess I've overlooked the basic carb scenario by reading most here saying vac/leak /pressure check. I'm certainly capable of replacing, but with this saws condition, I think I'd prefer OEM or even a carb kit

 

[irhunter]

The way you treat the saw--really well--it shouldn't need either seals or a carb kit.

But, it probably does.

It stinks that full-service Stihl dealers can't all be relied on to do something simple like this.

But, they can't.

So, if no one comes along with a suggested repair shop...you'll probably need to just buy the p/v tester or do a carb kit.

I'd suggest the former, as you'd like to pressure test the carb if you get around to rebuilding it...and, you need a pressure tester for that.

Roy

 

[Wood Doctor]

Thanks Wood Dr.
I guess I've overlooked the basic carb scenario by reading most here saying vac/leak check. I'm certainly capable of replacing, but with this saws condition, I think I'd prefer OEM or even a carb kit

One other thing that is worth trying first. Check the final screen filter inside the carb. It may be clogged enough to mess up the idle. Part #26 below:

These clog up and need to be cleaned (or replaced) every few years or so. They sometimes show up in rebuild kits. But, usually a simple clean up is all you need to do.

 

[slowcar281]

I would go ahead and invest in a mity vac, they are really good to own. There are block off kits for the intake and exhaust that you can buy for cheap, or make your own.

Does the saw drastically change idle if you turn it on its side? Sometimes that can be indicative of an air leak, typically crank seals.

You can try cleaning the carb, and putting a kit in it. If that doesn’t work I’d highly recommend an OE carb.

If you were closer I’d gladly pressure test the saw and install crank seals if needed

 

[StihlsawuserMS361]

slowcar,irhunter, I haven't noticed or checked for running differently while saw turned sideways, I'll check.
From my limited search, OEM carbs are about $100, kits about 1/2.
Seems Walbro carb kits are a bit less without the "Stihl" badge
Thanks for your help and offer

 

[stihltech]

#1 repair on a 361-Fuel hose.
The saw is 16 years old. Time to get the whole diagnosis done if you want to keep it.
Vacuum and pressure test FIRST!!!!! (I try to impress that on people).
Impulse and fuel line. I don't care if they are not leaking right now- they will.
Seen a few leaking cylinder gaskets. Even when tight.

2 hour commute to Pike.

 

[guym3]

I've just rebuilt an old 361 which had lots of issues.
As above, diagnosis is best done first. So vac/pressure test is always a good idea.

I easily found a second hand oem 361 carb on ebay for 40usd. They come up regularly. Often the AM ones are fine too.

Mine had a tiny air leak on the outside of the bearings. A bit of loctite and packing the back of the oil pump with grease has fixed it. May not need to spend a fortune to get it running with some basic repairs.

 

[irhunter]

OEM carbs are about $100, kits about 1/2.

Seems Walbro carb kits are a bit less without the "Stihl" badge

Actual Walbro full carb kits (not the smaller diaphram/gasket kit) are generally <$15 delivered.

 

[StihlsawuserMS361]

I'll have to search a bit better on kits then, thank you.

I guess its the fear of the unknown M3 ! It's not the cost of p/v, just pushing to do it

 

[HillyJohn]

Agree with advice to replace fuel hose and rebuild carb. My 2011 MS361 has just got the same problem ( needed carb and fuel line 4 years ago). When the carb is off, check the inlet manifold and impulse line between the handle and engine, as my intake manifold has just split, these saws have good antivibe, which means lots of movement on these tubes. Worth replacing these before worrying about crank seals, which are harder to replace.

 

[Mad Professor]

slowcar,irhunter, I haven't noticed or checked for running differently while saw turned sideways, I'll check.
From my limited search, OEM carbs are about $100, kits about 1/2.
Seems Walbro carb kits are a bit less without the "Stihl" badge
Thanks for your help and offer

Actual Walbro full carb kits (not the smaller diaphram/gasket kit) are generally <$15 delivered.

The Steal dealer thinks parts are made of gold.

Don't buy cheap AM carb kit, but should be able to find OEM Walbro kits for ~$15-20 delivered. Complete kits cost more than just gaskets/diaphragms.

Kits may service several variations of same carb. Remove the covers and keep gaskets/diaphragms in order. Match those with what is in the kit. Blowing out with air may ruin any check valves

 

[slowcar281]

If you don’t have access to an ultra sonic cleaner I’ve had some luck stripping the carb down and letting it soak in a mason jar filled with Amsoil power foam. That stuff really cleans well.

After a day or 2 I’d spray out all the passages with gum cutter and install a walboro kit.

I’ve never had any real luck with any aftermarket carb. I pulled my hair out a couple of years ago on an MS310. Finally ponied up and bought a Stihl branded carb and all the running issues disappeared.

If you haven’t opened up the muffler on the 361 you probably wouldn’t even have to pull and trim the limiter caps on a new OEM carb.

 

[StihlsawuserMS361]

I do have an ultrasonic cleaner, from back in the Oldsmobile days of cleaning diesel injectors. What's the preferred solvent for the tank, and heat or no heat?

 

[stihltech]

Why is everyone scared of a vacuum/pressure test? A basic 2 stroke test.

Yes you can get some brake cleaner (or carb cleaner) and spray around seals, gaskets, hoses, boots seals, etc. to test also.
BUT everyone wants to put on a carb (a CHEAP one) and then blame the saw because it won't run right.

Basic diagnosis wins every time.
End of rant.

Dodging 'maters.

 

[StihlsawuserMS361]

I don't know why everyone is scared of VP test. Some of us, including myself who doesn't have a fleet of chainsaws, would rather have a pro who's better versed, experienced and skilled at fixing something that is greek to me. Spend once, cry once I suppose. That's one reason why I'd rather pay for repair ,than buy a drawer of tools I'll only use once. Too many drawers full of those already. Spraying works, if you can keep it localized away from the intake.

Off topic a little, two cycle sleds were simple back in the day. Much larger engines, easier to work on with large hands.

I do agree with Stihltech, , and will never use a cheap knock off carb. My time and yours is worth more than saving a few $$$