550xp running like *hit trying the fixes now...

[Brent Nowell]

bought this saw brand new in August of last year I believe. Initially it seemed to run well, but the more I broke it in, the worse I felt it running.
The biggest complaint I had with the saw was how fricken hot it got, as in the front handle was burning my hand through my gloves!
I did a muffler mod and although it was much louder it absolutely was cooler, literally

So fast forward to just before spring here and I take it out to delimb a tree, and it just won’t fricken idle. Stalls out all the time if I let go of the throttle and falls flat on its face stalled when I give it throttle. Only way to keep it alive was to keep the rpms up.
Also noticed it was taking forever to start, like 10-15 pulls after primed... was about ready to throw it in the river until I remembered how much this thing cost !

Did some reading and found you could ‘reset’ the saw by running it through wood at 3/4 throttle for 60 seconds or some mumbo jumbo... however it appeared to work... put the saw down as the artic polar vortex kicked in and fast forward to today...

Couldn’t get it to start and when it finally did idling like total **** and falling flat on its face again...

Pulled the carb and drilled a tiny hole in the brass cap, removed cap with pick and set screw 1/4 turn out. Put it all back together fired it up and it was missing quite a bit in the cut. Thought air leak and went to pull the plug, well plug was loose... facepalm
Ok let’s try that again. Idled pretty good and found that it had its advertised throttle response, which was instant.
Tried a hot start, fires up with half a pull.
Ok so let’s wait for it to cool down, try this again and see... this is where I’m at now.
If it passes that test and runs great I will try the saw again when the temp change is much colder/hotter than it is now and see what happens.

If nothing changes I will have no choice and go through the BS of warranty repair... what a hassle but I’ll update this thread as things pan out

 

[Andyshine77]

What model crb is on the saw?

 

[hamish]

If you had a good dealer you would have already taken the saw there, good luck trying to get warranty.

 

[superwd6]

If you had a good dealer you would have already taken the saw there, good luck trying to get warranty.

I to played with the screw behind cap with no success trying to get rid of slight hesitation. Took it to a different dealer that has all tools, training and keeps up to date with new equipment. I paid to check for errors and update software and saw has been perfect since [emoji16].
What saw doesn’t like is 32-1. , 40-1 or any of the heavy motorcycle oils with high flash points. It runs perfect on 50-1 FD oil just like the manual states. I run Motul 710 50-1 mix so it still smells like dirt bike while I’m working [emoji7]. And I don’t waste time on compression testers either[emoji23]


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[Brent Nowell]

I to played with the screw behind cap with no success trying to get rid of slight hesitation. Took it to a different dealer that has all tools, training and keeps up to date with new equipment. I paid to check for errors and update software and saw has been perfect since [emoji16].
What saw doesn’t like is 32-1. , 40-1 or any of the heavy motorcycle oils with high flash points. It runs perfect on 50-1 FD oil just like the manual states. I run Motul 710 50-1 mix so it still smells like dirt bike while I’m working [emoji7]. And I don’t waste time on compression testers either[emoji23]


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When did you get the update? Was it recently?
I got an update for it according to the dealer in September. Just wondering if you got yours after or before. If it was before then we probably have the same firmware.

How do I check to see which carb I have?

 

[Brent Nowell]

Cold started it just now, minor hesitation until engine warmed. Idle is strong and consistent, didn’t tach it but it sounds normal.

Throttle response after about 30 seconds of blipping it until warm was really good. Shut it off, no decomp, flipped switch up then down for throttle assist start and it fired right up one pull.
*so far there is an improvement after adjusting the screw...

Checked side covers for leaks at idle, all I had was brake cleaner but I have used it before for air leaks and it will stall the engine. When I sprayed the side covers there was no change on idle.


Note, don’t use brake cleaner on rubber hoses it will destroy it after time leaving cracks. Killed my fuel lines on my mculloch cleaning out the carb area.

 

[Allen miller]

Cold started it just now, minor hesitation until engine warmed. Idle is strong and consistent, didn’t tach it but it sounds normal.

Throttle response after about 30 seconds of blipping it until warm was really good. Shut it off, no decomp, flipped switch up then down for throttle assist start and it fired right up one pull.
*so far there is an improvement after adjusting the screw...

Checked side covers for leaks at idle, all I had was brake cleaner but I have used it before for air leaks and it will stall the engine. When I sprayed the side covers there was no change on idle.


Note, don’t use brake cleaner on rubber hoses it will destroy it after time leaving cracks. Killed my fuel lines on my mculloch cleaning out the carb area.

I guess I'm lucky bought a used one did a muffler mod and cut base of cylinder down and a little porting .I run the **** out of it. I've had it for 5 years now . I can't remember last time I grabbed my 346xp. Like it so much thanking about replacing my 044 with a new 572xp . I've never had my saw tuning updated. I see post all the time over 550 issues. I don't get it mine is a early 550 to.

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[mbrick]

I wouldn't spray carb cleaner wildly hoping to find a leak. Unless it's massive and the cylinder bolts are loose...

Check cylinder bolts. If you want to leak test it make some block off plates and do a vacuum/pressure test but I'm sure it's find.

Sounds like you figured it out with the spark plug though!

 

[superwd6]

When did you get the update? Was it recently?
I got an update for it according to the dealer in September. Just wondering if you got yours after or before. If it was before then we probably have the same firmware.

How do I check to see which carb I have?

Update was done well over a year ago. Cold start ,then let it idle for minimum 30 seconds then 0 hesitation. Now another forum said Stihl 261cm was perfect and didn’t need idle time to warm up and rev with no hesitation but friend has 261cm new style that needs same idle time as my 550 [emoji849][emoji23]


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[Brent Nowell]

Update was done well over a year ago. Cold start ,then let it idle for minimum 30 seconds then 0 hesitation. Now another forum said Stihl 261cm was perfect and didn’t need idle time to warm up and rev with no hesitation but friend has 261cm new style that needs same idle time as my 550 [emoji849][emoji23]


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Funny how that is, people are excited about their recent adoption of new technology and say how awesome it is. Sometimes though they just don’t have enough hours on it to make an informed opinion about their equipment. I am definitely guilty of this myself.

Brought down a nice pine today for killing with the 550 and a speedcut b&c 18” and it ran like a top.
Had it idling quite a bit I between Delimbing and moving brush out of the way and it was noticeably stronger.
It did stall twice for no apparent reason within that hour, but fired up right away. Hot starts were also not a problem.
More time will tell in which I will update this thread

 

[Derrick Sawyer]

Out of the whole intitial description, what i remember the most is the loose plug, was it loose enough to let air in and you unscrew by hand or just loose like it was pretty easy to loosen with the wrench but probably not leaking air? I myself paranoid about putting it on too lose so i tighten it pretty good, similar to the ones on the car, i guess, especially the spark plugs with a washer like the NGKBPMR7

 

[Derrick Sawyer]

And dang that is a sweet assasin looking saw, barely looks used

 

[Brent Nowell]

Out of the whole intitial description, what i remember the most is the loose plug, was it loose enough to let air in and you unscrew by hand or just loose like it was pretty easy to loosen with the wrench but probably not leaking air? I myself paranoid about putting it on too lose so i tighten it pretty good, similar to the ones on the car, i guess, especially the spark plugs with a washer like the NGKBPMR7

Yes it was pretty loose enough to let air in. I noticed something else to be off when I was cutting it was missing at high rpm.
The last time I serviced it I obviously forgot to tighten it...
these idling issues were happening long before that.

And yes the saw has only 4 or 5 tanks through it, not been used much at all. So far it’s running good, and I have to admit that felling with it is an absolute pleasure. Extremely light and cuts quick.. makes me start to think why I need anything bigger for felling and firewood.
Then again I ain’t no veteran, only been playing around with saws for a couple years, before that I didn’t know **** from shine-o-la lol... sometimes I still think I don’t haha

 

[Rjpoog1989]

I guess I'm lucky bought a used one did a muffler mod and cut base of cylinder down and a little porting .I run the **** out of it. I've had it for 5 years now . I can't remember last time I grabbed my 346xp. Like it so much thanking about replacing my 044 with a new 572xp . I've never had my saw tuning updated. I see post all the time over 550 issues. I don't get it mine is a early 550 to.

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We have an early 550 at work and it’s been a very reliable saw. It has a ton of hours on it and runs like new. We broke the handle on it a few months ago, but I believe that to be operator error (not me running it at that time).

 

[Brent Nowell]

Brought it out again today, ran two tanks through it, didn’t miss a beat it seemed. Was very impressed just kept going. Had it on its side idling, rolled over upside down idling while i was doing something kept going. Temp was just at freezing so there was large degree in temp change from last time it ran.

I wonder what the issue was now, was it the screw I turned in, or was it the somewhat loose carb mounting bolts that I tightened??
I’m tempted to turn the screw back in and see how it runs now?

 

[Brent Nowell]

Update...
After some extensive use it just sounded a little lean in certain rpms... had a few starting issues as well, seemed to be once every time I brought it out it would not start up properly... so I took off the air horn again and decided to adjust the screw back to stock. 1/4 turn back in it goes..

We will see what happens from this point on...

I’m starting to think the saw would not idle due to the loose carb mounting bolts I found in an earlier post within this thread....

 

[CenterTree]

Update...
After some extensive use it just sounded a little lean in certain rpms... had a few starting issues as well, seemed to be once every time I brought it out it would not start up properly... so I took off the air horn again and decided to adjust the screw back to stock. 1/4 turn back in it goes..

We will see what happens from this point on...

I’m starting to think the saw would not idle due to the loose carb mounting bolts I found in an earlier post within this thread....

Have ya run it since you turned the screw back in? Curious to see what if any effect that lil screw even has.