Me and my stihle 650 chainsaw

[alsayyed]

Dear friends yesterday I have carried the Stihl 650 chain saw for cutting some wood which I put the chain saw to work until it got hot and stopped. This afternoon I have tried to started ti but it is not groining any more it became stubborn. I pulled the plug and cleaned the carburetor filter and cleaned everything but it will not start. So my son told me change the plug maybe it will work. My question how often do I need to change the spark plug? I am praying that the engine is OK beside the chain saw is brand new it is only one month old. Has anybody folks running in the same problem I am running into. Need advice please because I love to work with the chain saw.

[mike_van]

A spark plug can last for years, here's a quick list of things to check - Was the gas/oil mix correct?  Does it still have enough gas in it to start & run?  You can check the spark by removing the plug, have the wire attached, the base of the plug against the head, pull the cord [with the on/off switch on], there should be a good spark at the plug gap.  Go through the owners book, see if you missed anything easy.   Good luck with it, let us know -

[rebocardo]

> any more it became stubborn

If you adjusted a chain and made it tighter when it was hot, it is possible once it cooled it got tight enough to prevent you from being able to run/start the saw. I did that once and just loosened the chain a bit.

[alsayyed]

I have mixed gas and oil again according to the manual. I have cleaned the fileter and cleaned the saw it self and tried to started it in all modes but won't starts this time became real stubbon. I hope and I am praying that nothing happeaned to the engine. ???

[Kevin]

real stubbon

...as in hard to pull or just won't fire?

If it just won't fire check for spark and check to see if the plug is wet with fuel.

[alsayyed]

i had just changed new spark plug which costs me $2.50 . I tried to fire the engine but will not fire. I started to lose patient with this chainsaw . And there is no stihl center in Qatar. maybe problem with the engine which I doubt it becuase the chainsaw is  new.

[TRUSSMAN]

If it were me, i would take it back to the dealer, it should still be under warranty.
Jeff

[Dan_Shade]

does the cord pull harder than it used to pull?

if you still can't get it started, remove the muffler and pull the cord until you can see the piston.  check to see if the piston is smooth or has several grooves in it.

[Bill]

Alsayyed

For your sake I hope its something simple like -

Checking to make sure that you have enough oil in the tank to lube the chain  or
Adjusting the chain so that it is not too too tight and also not too loose  or
Using the right oil ( proper air cooled two stroke oil mix ) to gas ratio in your fuel   or
Maybe something got caught in the chain and is jamming things up ( dirt/sand/cloth/etc )

Also if its really HOT when you cut wood you may want to consider what some of the others on this board do with their own saws - instead of a 50 to 1 ratio some of them drop it to maybe 40 to 1 - just careful if you deviate from the manufacturers specs as you are on your own.

Good Luck

[alsayyed]

I almost started it but not quiet I have changed the gasoline and oil mix three times. I have started the engine only if I hold the throttle trigger, if I release the throttle trigger the engine stops then I have to do it again. The problem is almost there but it seems to me that is hidden somewhere. Any advice chain saw owners. Let me tell you something I did not change the carburetor setting.

[Ernie_Edwards]

Not an expert here, but, could the brake have accidentally been set?

[alsayyed]

No I almost cautious in not runing the chainsaw while the brake is on. this will demage other parts.

[Bill]

Alsayyed

Maybe you might want to double check the chain and bar. Does the chain turn freely when the saw is off ? Maybe the clutch/brake is malfunctioning or jammed ?

If the chain is OK I think I'd check for spark then look at the fuel system and also make sure nothing is blocking air to the motor.


Good Luck

[alsayyed]

Thank you Bill actually I am running the saw without the bar and the chain. But I the sprocket am running when I start the machine. I have removed the carburetor filter then started the chain saw and I can feel the air is coming out and the gasoline drops from the carburetor. The break is working ok. I have read the manual few times. I have used fresh gasoline mixed according to the manual.

[Kevin]

I am running the saw without the bar and the chain.

Don't do that.
It sounds like it's getting too much fuel and is flooded.

[Bill]

Alsayyed

Kevin 's warning is right on. It does sound like that if you can get it running there is spark. Now you just need to figure out whether its a fuel supply problem or a jammed chain/bar issue. If you can't move the chain when the saw is off I'd lean to something holding up the chain but if the chain turns freely it sounds like its flooded for some reason. Is the plug wet with unburned fuel when you try to restart - a sure sign of flooding. FWIW I keep spare bar(s) ( a different length for different size jobs )  and chain(s) available so I don't have to stop work if there's a problem with them. Maybe you might want to consider a couple spares.

Good Luck

[Minnesota_boy]

If you were using the saw hard and it got hot and stopped while you had it running, it is quite possible that you have overheated the engine and melted the front edge of the piston.  That will lower the compression causing it to start hard, possibly much harder to crank over.  It will have little power and will not idle if this is the case. 

Remove the muffler and look at the piston.  With the engine turned off, pull the rope slowly while watching the piston go up and down.  It should have no groves in the piston and the top edge should have a sharp edge.  You probably will want to take it to a knowedgeable repair person if this is the case.  This could be a warranty item if the saw was set too lean at the factory.