Stihl Fs460 bogging

[northman]

So as the title says my Fs460 is bogging on full throttle, I've changed the plug, cleaned the filter and I run aspen exclusively so it's not **** fuel. Anyone else had this problem with theirs? Oh Yeh it's mtronic also.

[Richard 1234]

Have you checked the valves are set right. I think it's a 4 mix if it's not just ignore me😁😁

[northman]

Have you checked the valves are set right. I think it's a 4 mix if it's not just ignore me😁😁

 

It's a regular 2 stroke dude, but cheers for input.

[Richard 1234]

One other thought is the exhaust port half full or more of unburnt fuel/oil mix. This happened not long ago on one of my 2 stroke strimmers. It had no top end revs but not too bad low down? Worth taking the exhaust off to look maybe

[Burgess]

Might be the m-tronic has gone and isn't setting the carb right?

[miker]

I have had several strimmers/brushcutters that had same problems, took out spark arrestor in the exhaust,cured the problem straight away, but i run normal 2 stroke and not aspen, but worth a checking

[northman]

So since posting this thread the machine went into my local dealer who couldn't find anything wrong with it, so just gave it a service. Now after that it did maybe 1 or 2 jobs since being parked up for the winter. So now the season is back in full swing I've gotten on site with the machine and it's bloody playing up again nothing down at full throttle as soon as it's warned up. So again I ask has anyone else had this trouble with their fs460. Just for reference it's only run on Aspen or motomix, filter is clean and it's always run with the guard on so no 2ft strimmer line which I've heard can cause a similar problem. Cheers!

[roys]

I had the fs450 that I was convinced had a fuel issue, stripped the carb down, cleaned and poked about still use to flatten out at full tilt under load, eventually just changed the spark plug to eliminate it, hey presto sorted, must have been breaking down under load.

[s.varty]

I had the fs450 that I was convinced had a fuel issue, stripped the carb down, cleaned and poked about still use to flatten out at full tilt under load, eventually just changed the spark plug to eliminate it, hey presto sorted, must have been breaking down under load.

 

Champion plugs were prone for this, NGK:thumbup1:

[carlos]

So since posting this thread the machine went into my local dealer who couldn't find anything wrong with it, so just gave it a service. Now after that it did maybe 1 or 2 jobs since being parked up for the winter. So now the season is back in full swing I've gotten on site with the machine and it's bloody playing up again nothing down at full throttle as soon as it's warned up. So again I ask has anyone else had this trouble with their fs460. Just for reference it's only run on Aspen or motomix, filter is clean and it's always run with the guard on so no 2ft strimmer line which I've heard can cause a similar problem. Cheers!

 

we had a fs450 that would work for about 20min then revs would just die off till it was unusable. in some part of the carb there was a tiny little metal gauze filter that was full of grey gunk cleaned it out and it was fine after that, sorry i cant remember which exact bit of carb it was in maybe someone else can explain , but was an easy fix. hope this parts diagram link works i think the guaze is part no.24

might help or could be way off! carl

https://www.google.ie/imgres?imgurl=http%3A%2F%2F2.bp.blogspot.com%2F_nOJqAqaBIwk%2FRtchjR-DltI%2FAAAAAAAABRg%2FPeUf7Y7NPVk%2Fs400%2F392ET064.JPG&imgrefurl=http%3A%2F%2Frepuestosmaquinas.blogspot.com%2F2007%2F07%2Fillustrated-parts.html&docid=wkC8OX5TDlIPeM&tbnid=JRIwlGW3Th8_LM%3A&vet=10ahUKEwiwwNWMk6XUAhUCBcAKHamTC6UQMwgoKAIwAg..i&w=400&h=315&bih=653&biw=1366&q=fs%20450%20parts%20diagram&ved=0ahUKEwiwwNWMk6XUAhUCBcAKHamTC6UQMwgoKAIwAg&iact=mrc&uact=8