My Stihl chainsaw is giving problem again .

[alsayyed]

Yesterday I went to practice some  slabbing a log using the Stihl 650 chainsaw, the reason I decided that day because I have purchased a new ripping chain, but could not make it through because my chainsaw bar is not straight I explained the problem on the earlier on other thread. Anyway my question is I have tried  to start the machine after 5 strokes then started I followed the full procedure in starting the machine. But I have discovered the machine runs for 3 minutes then once I release my hand the machine stops. Then when I try to start it again it will not start unless I open the spark plug and clean it then I started again. But my main concern and my agony are starting the chainsaw. I have mixed the gas and 2stroke oil exactly. Anybody having problem with Stihl chainsaw or just the I ma the only one on the forum.

[fishhuntcutwood]

So you keep your hand on the throttle to keep it going?  Am I reading that right?  In my mind, the way I'm interpreting what you've said, I'd look to your L screw, as it sounds too rich.  If you're keeping the saw under throttle, and the carb on the H circuit, which is adjusted properly, it'll run.  But once you let it idle on the L circuit, it loads up and dies.  Then you have to clean the spark plug.  Is it wet or just really coked up?  Is this problem recent, or have you done anything to it? 

The easiest thing to check is for leaks, which would run you lean, but a leak is a leak, and easy to find.  Check your impulse line and the elbow from the carb to the intake port.  That done, I'd check your carb.  Start at standard settings, which is one turn out on each screw from lightly seated.  This will get you started. 

Someone will likely read your post and know exactly what to do, but from the way I read it, that's the picture in my head.

Let us know...

Jeff

[Rocky_J]

It sounds like you are paying for mistakes you have already made and damage you have already done. I suspect you have already damaged the saw from early mistakes. The bent bar, broken chain adjuster, dull chain and improperly adjusted carb all hint toward even more severe damage caused by your abuse. I would suspect the piston and rings are damaged from excessive heat and scoring.

[Kevin]

I'd be looking at a carb adjustment , the flooding is most likely due to choking.

[alsayyed]

It sounds like you are paying for mistakes you have already made and damage you have already done. 

I have already fixed everything exccept the bar which  just been ordered from Baileys. I replaced the spark plug, and anyway the spark plug always clean. The piston looks good. it stops only during the idling. what I have noticed whenever i take the spark plug out i clean the plug and insert it again when i fire  it i will start again but it will not continue more than one minites it stops in idling mode I have checked for leak, and no leak at all.

[New Inn Wood Man]

Hi Alsayad,

One simple thing that is worth checking is whether the air filter is clean. Its a simple thing but if blocked will give you all the symptoms you have and can send you off stripping bits down when you do not need to. Clean as per maintenance book.

One other point to consider is whether the choke is working correctly. It is possible that the choke is jammed partially on. This can easily happen after stripdown for other things. Also make sure you are turning the choke off fully as soon as the machine will allow.

What effect does the choke have? If when running you put it on does this change the running of the engine? If it does not then there is your problem.

One last thing. If you suspect your piston and rings to be giving low compression hold the machine by the starter handle only. On a new machine the compression will stop the pull cord from unwinding and the machine will not drop or drop very slowly. On a machine with no compression the machine will fall groundwards very quickly like a yo yo. ie there is insufficient compression to support the weight of the machine.

Hope these simple things help.

Richard

[SawTroll]

I think Jeff may be on the right track here, about the L adjustment.  :-\

How far out from lightly seated is the L screw?
If you don't know, try too seat it lightly, back it out one turn, and see if it helps.

Hopefully Rocky is a bit pessimistic here , but I suspect he may not....

[Alta]

Dont take this wrong, but I think you should take it to a good saw shop that works on Stihl saws. Its an expensive saw to be experimenting with and if Rocky isnt right yet he probly soon will be.

[beenthere]

I may have read wrong and misinterpreted alsayyed's situation, but I really don't think he has the luxury of a chainsaw shop anywhere close. I think this Forum is his best contact to the Stihl experts that are trying to help.  As I understand, he is a 'pioneer' in the chainsaw world where he lives. Alsayyed, correct me if I am wrong here. 
Many on the forum are working hard to understand the problems which have likely compounded into several.

Alsayyed, maybe you could let us know what your options are for getting your complete saw to a dealer for a check-up. Anything in your country?  Or possible to send it away? 

When Alsayyed perfects his picture posting, maybe he can send several to give us an idea what conditions, logs, sawing, attempts, results, and other related situations are through the pictures. Fortunately, Alsayyed's english is pretty good, but am wondering if some important interpretation is being lost in some of the translations.

I will admit that when my MS361 needed an idle adjustment, I had to pinch myself to follow the saw's manual on the procedure, as I didn't find it very intuitive from my past engine carb experience. So I force myself to read the directions and follow them to the letter (even the letters don't make sense  )

[Bill]

Alsayyed

I agree with Jeff and Richard - sounds like its running too rich - whether from aircleaner being clogged, choke malfunctioning, or low speed idle screw adjusted too rich. When any engine is too rich the spark plug(s) fouls and the engine stops. Once the plug(s) is cleaned/dried it runs again till loading up again and needs to be cleaned again. Sounds like your saw.  ( A long shot might be a severe restriction in the exhaust system but that would be rare - IMHO. )

I too remember you mentioning that you are pretty much alone as far as support goes because there are no dealers or users in your country. Where did you buy your 650 ? Maybe you could send it to them for a "tune up" ?

If you look back in the Forestry Forum you'll find several posts and links about how to adjust and tune a chain saw. I think you may find them helpful once you determine the choke works and the air cleaner is itself clean.

Good Luck

[Kevin]

...and never make any carb adjustments unless the air filter is clean.

[SawTroll]

How far out from lightly seated is the L screw?
If you don't know, try too seat it lightly, back it out one turn, and see if it helps.

:-[Sorry, this advice may not have been very good.
I forgot about the limiter caps, which makes the prosess more complicated, as you have to remove them before you are able to seat the adjustment screw(s).