Stihl 441 problem

[onetruth]

I have a problem with my 441.  Basically it cuts out within a couple of seconds at full revs, and can manage maybe 15 seconds max under load if I only throttle it half-way.  The exhaust also seems abnormally hot.  No problems starting (hot or cold), the saw hasn't seen much use (still on first bar).

 

I am loathed to take it to the dealer (not very close) as it means losing two whole days - one to take it and one to retrieve it, but having read this thread I fear it may be the only option.  Can anyone suggest anything simple I could try beforehand?  I'm pretty ignorant when it comes to engines - I doubt I'd recognise a carburettor if I shat one out.   

 

Thanks!

Edited August 9, 2018 by onetruth

[Rough Hewn]

Take the spark plug out and photograph it.
Should tell a story.
[emoji106]

[onetruth]

11 minutes ago, Rough Hewn said:

Take the spark plug out and photograph it.
Should tell a story.

[Rough Hewn]

Looks ok ish,
I'm no mechanic, just do my own saws.
Could be many things.
Start with the cheapest and easiest to change.
There are a few guys on here who know saws well.
How old is the saw?
[emoji106]

[onetruth]

11 minutes ago, Rough Hewn said:

Looks ok ish,
I'm no mechanic, just do my own saws.
Could be many things.
Start with the cheapest and easiest to change.
There are a few guys on here who know saws well.
How old is the saw?

Two years I think, occasional use.  Never been serviced, though, and apart from sharpening the chain, gets very little tlc.  This is the first time the spark plug's been removed, for example.  Air filter looks really clean.  Fuel filter looks (as far as I can tell) ok.  I don't think that this is the saw that I put chain oil into the fuel tank! 

[spudulike]

Does the saw idle OK with no issues?

If it does idle OK then it sounds like fuel starvation when the saw is under load or max revs. Typical issues - split or kinked fuel line, blocked breather, blocked gauze strainer in the carb, carb needs cleaning from standing, blocked fuel filter etc

[onetruth]

2 hours ago, spudulike said:

Does the saw idle OK with no issues?

If it does idle OK then it sounds like fuel starvation when the saw is under load or max revs. Typical issues - split or kinked fuel line, blocked breather, blocked gauze strainer in the carb, carb needs cleaning from standing, blocked fuel filter etc

It idles OK, but there may be issues.  It doesn't cut out but might rev a little high - I think the chain creeps on occasion (though not constantly).  Of the causes you suggest, the fuel filter and fuel line are, as far as I can see, ok.  The other suggestions are beyond my ken: I've never even heard of a "breather" outside of Roger's Profanisaurus.  

 

Thanks, both of you, for your efforts to help.  I think it'll probably be for the best if I just take it back to Gustharts to sort out: if I try to fix it myself I will no doubt end up fibbering the small-end gasket, or something of equal meaninglessness and expense to myself.

[bmp01]

Breather just let's air into the fuel tank - so you don't end up with a vacuum in there as the engine uses the fuel. Completely blocked and you'd not restart the saw. ... partly blocked,  maybe

Quick and dirty test - no fear of breaking anything - run the saw up until it misbehaves,  switch it off,  undo the fuel cap, fuel cap back on, start it up and retest. 

If you can, try to note what happens as you open the fuel cap,  air being sucked in or expanding fuel being blown out. ...

Also worth noting a blocked (or part blocked) breather gives different symptoms with a full tank compared to a nearly empty tank. 

It'll be quicker for you to do the test than it took me to type this ?

 

 

 

 

Edited August 10, 2018 by bmp01

[onetruth]

1 hour ago, bmp01 said:

It'll be quicker for you to do the test than it took me to type this ?

 

Unless you're blind, I doubt it!  Managed to do this just replacing the spark plug to perform the test...

 

Off to the dealer's now.  I don't think I'm going to sharpen my chains any more - there must be a 50:50 chance that if I do my house will fall down.

[bmp01]

Uh ok....

That probably happened when you pulled the cap off, you've just finished it off stretching it to put it back on. 

There's always Mr Spud's repair service by mail if that saves you time and expense, I hear he likes to see a clean saw now and then.