Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Stihl => Topic started by: haasper on December 06, 2012, 06:19:54 pm


Title: ms361 not starting
Post by: haasper on December 06, 2012, 06:19:54 pm
decompression button pops ,closes ,when pulling starter
it does not fire up or start
what could be the problem?
it pulls very hard when the compression is closed
Title: Re: ms361 not starting
Post by: 660magnum on December 06, 2012, 06:34:14 pm
That saw is flooded or something?

Wrong decompression valve, wrong piston, or something?  Maybe just the decompression valve is bad?
Title: Re: ms361 not starting
Post by: Cut4fun on December 06, 2012, 07:37:02 pm
Pull muffler and look at front of piston and back of cylinder for scoring aka scuffs.  Pull plug look at front of cylinder with flashlight through hole. Look for scuffing.

Check for spark to plug.
Title: Re: ms361 not starting
Post by: haasper on December 07, 2012, 07:16:37 am
checked you guys recommendation, still the same
before this i rebuilt carb and replaced coil module
seems to me it wants to fire to soon, out of timing?
the ms361 from day one was always very hard to start
15 plus pulls
all the stihl models before this started great, never let me down
any ideas what to check next?
Title: Re: ms361 not starting
Post by: Chris J. on December 07, 2012, 12:35:19 pm
NOTE--It helps to follow the starting procedure recommended by Stihl.   I rearely deal with Stihl saws,  esp. newer ones,  so it was a learning experience for me.  Sometimes I'm a bit dense ;D.

I had a MS 361 that i got from a pawn shop,  it started & ran at the PS.   I got it home,  dumped the old fuel,  gave it a good inspection,  reinstalled everything,  & fueled with my mix.   It started & ran fine;  I gently revved for a while (no wood to test it :() to let the fresh fuel work it's way through the carb.

A few days later it wouldn't start at all.   I ended up having to 'reconnect' the spark plug wire to the spark plug cap.   I'm thinking that someone pulled & yanked on it when it first wouldn't break free,  a mistake that I've made working on my cars.
Title: Re: ms361 not starting
Post by: Cut4fun . on December 07, 2012, 01:16:08 pm
Have you checked for spark with tester? If spark. Have you checked to see if the plug is getting wet from fuel?


Here is another 361 that didnt start   http://chainsawrepair.createaforum.com/stihl/ms-361-not-firing/
Title: Re: ms361 not starting
Post by: haasper on December 09, 2012, 09:39:11 am
working on the spark plug
seems the spark is not at the electrode
the spark is in
 other places like blue flashes
have the lights out to see it better
new module with new wires installed
short somewhere? flyweel ?
holding the plug to the cylinder head
to check the spark
Title: Re: ms361 not starting
Post by: Cut4fun on December 09, 2012, 11:54:11 am
I have both of these for testers. Works inline. Leave plug in cylinder.   http://www.harborfreight.com/catalogsearch/result?q=spark+plug+tester


Jumping spark all around saw :o I havent seen. Maybe someone else has info.
Title: Re: ms361 not starting
Post by: JohnG28 on December 09, 2012, 09:42:30 pm
Maybe a new spark plug would hep? My 361 was hard to start early on, opening the L side up a little made a huge improvement, especially when warm. I have also heard of the decomp valves popping on a high compression saw even if it didn't start. Never had it happen myself, but possible I suppose.
Title: Re: ms361 not starting
Post by: haasper on December 10, 2012, 03:56:18 pm
have a new plug
cannot get a spark from the electrode to the gap
a bluish spark or bluish light is on the outside of the plug
when pulling not at the electrode where it should be
sure is a puzzle
Title: Re: ms361 not starting
Post by: Cut4fun on December 10, 2012, 04:05:03 pm
Even though new. You sure your plug isnt ****, you wont be able to see it very fine line and cause it to jump fire.

Try another plug.
Title: Re: ms361 not starting
Post by: haasper on December 11, 2012, 08:55:21 am
thanks red neck
ordered from habor freight spark plug tester
ordered fly wheel puller for ms 361
there has to be a short some place
the current is not going to the electrode to show it is firing
Title: Re: ms361 not starting
Post by: JohnG28 on December 11, 2012, 09:46:28 am
Even though new. You sure your plug isnt ****, you wont be able to see it very fine line and cause it to jump fire.

Try another plug.

I'd try another plug also. If the spark is dancing around the side of the plug something isn't right. I don't know how the coil could cause this condition?
Title: Re: ms361 not starting
Post by: haasper on December 13, 2012, 09:41:17 am
need to buy a new flywheel
stihl part #1135 400 1200
can`t find it on the internet

plug and coil harness check ok
spark is still dancing
Title: Re: ms361 not starting
Post by: Cut4fun . on December 13, 2012, 10:32:40 am
Just curious does your magnets on your flywheel still have strong pull?
Title: Re: ms361 not starting
Post by: Jasonlopez on December 22, 2012, 02:10:03 am
need to buy a new flywheel
stihl part #1135 400 1200
can`t find it on the internet

plug and coil harness led lighting (http://www.niceledlights.com) check ok
spark is still dancing

Get a new spark plug
Title: Re: ms361 not starting
Post by: haasper on December 23, 2012, 11:34:35 am
got the inline spark plug tester
starter pulls to hard and slow no spark
took the decom. out
good spark it pulls easy
getting a new decom valve
let you know the results when installed
Merry Christmas
Title: Re: ms361 not starting
Post by: 660magnum on December 23, 2012, 01:36:10 pm
The old decompression valve is just plugged with carbon?

In fact, it is most likely the hole in the head that goes to the decompression valve and it may be free now that you took the valve out?

Try working the valve some with it out of the cylinder and it it is free, put it back in the cylinder and try it?
Title: Re: ms361 not starting
Post by: Cut4fun . on December 23, 2012, 02:21:49 pm
I use carb cleaner in a spray can to clean up de-comps that are still usable and not leaking.
Title: Re: ms361 not starting
Post by: Angelo c on December 24, 2012, 08:24:09 am
Ok guys , new here so forgive the tone, haven't figured out the volume or sense yet.

Why was the coil replaced in the first place?
Have you tried to plop a few drops of mix in the carb or down the plug hole to see if it will pop?( fuel delivery)
You say you rebuilt the carb, can you verify correct gasket and diaphragm order and jets open and flowing.?
I keep a plug that's threaded to the size of a decomp valve so you can eliminate the valve quick and cheap.
Have you checked for sheared key way on crank? (Timing off)
What kind of pressure and vac testing have you done to hoses, case and seals ect.

You need to eliminate some issues before chasing all possilities. I vac test every line and hose new or old. Work from knowns to unknowns.  8)
Title: Re: ms361 not starting
Post by: Cut4fun . on December 24, 2012, 01:30:35 pm
Ok guys , new here so forgive the tone, haven't figured out the volume or sense yet.

Why was the coil replaced in the first place?
Have you tried to plop a few drops of mix in the carb or down the plug hole to see if it will pop?( fuel delivery)
You say you rebuilt the carb, can you verify correct gasket and diaphragm order and jets open and flowing.?
I keep a plug that's threaded to the size of a decomp valve so you can eliminate the valve quick and cheap.
Have you checked for sheared key way on crank? (Timing off)
What kind of pressure and vac testing have you done to hoses, case and seals ect.

You need to eliminate some issues before chasing all possilities. I vac test every line and hose new or old. Work from knowns to unknowns.  8)

Got me  ??? he did all of that before showing up here.   

We just treat each other like adults here  and what ever you can do to help guys is appreciated.   Everyone has their specialty and having a broad range of folks with know how is good.

Thanks and keep it up. Hope to see things posted by you and learn from it too.  8)
Title: Re: ms361 not starting
Post by: haasper on December 28, 2012, 01:45:55 pm
thanks guys
saw is running
660 magnum was right ,decom bad internally
replaced it and away we go to the wood pile
happy new year
Title: Re: ms361 not starting
Post by: 660magnum on December 28, 2012, 04:42:43 pm
+1