50-1 in a 25-1 machine.

[AlexB]

It really was rubbish! Whilst I have your attention garden kit, my fs460 began doing odd things today. It would start and run but not rev. I've checked everything I can think of. I'm not upto taking apart engines though. Any ideas? Filters are clean, plug is good.

[GardenKit]

If it starts, but just sits and ticks over normally, then check the throttle cable and trigger. It could be just that the throttle butterfly is not moving.

 

If the butterfly is moving and the revs try to increase for a split second before dying back then that could would indicate a fuel starvation. If the tank filter is good and there are no holes or kinks in the pickup hose, then I would suspect the gauze inside the carb.

 

If the revs are increasing but unable to achieve full revs but not dying back then i would suspect that the exhaust system is choked with carbon or oil residues. This could be just the spark arrestor, or the whole inside of the exhaust or the exhaust port in the pot.

 

Remove the exhaust to check the port, if its clear you can run the machine without the exhaust on for a few seconds. If it runs up OK then there is a fair bet the exhaust is blocked (or the spark arrestor) Be careful running without the exhaust, it will be very loud, sparks and flames could come from the port, as well as very hot bits of carbon.

[AlexB]

Thanks! I'll have it to bits tomorrow! Fingers crossed.

[GardenKit]

Good luck!

[AlexB]

I think I know the answer here.....

[GardenKit]

Result!

Clean the pipe and see if it helps. Hopefully the inside and the port will be clear.

[AlexB]

Had it apart and was just the pipe. Not sure if it's operator not getting it hot enough or bad luck. Fuel mix is accurate and I've been using it for nearly 4 months 6 hours a day except yesterday when some one else used it.....

[GardenKit]

One day will not do this, that was just bad luck on that operator.

 

What oil are you using?

[AlexB]

Stihl hp. The red stuff.

[Guss109]

If I'm right in thinking I used the same oil for a week in my strimmer and it was belching out black smoke so took it to the shop to be looked at. They said it was because of the oil being thick and not burning properly so went back to using the stihl super hp and had no problems since. Hope this is of some use