Stihl hs 81 R

[LucH]

Hi not really a chainsaw but my stihl hs 81 is leaking oil on the muffler and exhaust it has new carburator,air filter,fuel filter and spark plug already tried torching the muffler still the same and it was already leaking before i changed the carburetor. everything works fine other than the leak. what steps do i do or should i just let it leak? Thanks 

[Dan Maynard]

Is it 2 stroke oil? What ratio do you mix your fuel?

[GarethM]

Mixture and probably not running it long or hard. See plenty of people running them like electric ones, start stop all day long.

 

You start one and you run it hard for half an hour.

[pleasant]

Either been run for sometime previously on an oil rich mix and the muffler is partially clogged so not getting hot enough to burn the excess oil off, or you are currently running a very rich mix and that is the excess oil in the vapour.

 

And when you say you have torched the muffler, did that entail actually removing it and getting it red hot all round? Whilst you had it off  did you check/clean or remove the spark arrestor (if fitted)

Edited 3 hours ago by pleasant

[openspaceman]

2 hours ago, LucH said:

Hi not really a chainsaw but my stihl hs 81 is leaking oil on the muffler and exhaust it has new carburator,air filter,fuel filter and spark plug already tried torching the muffler still the same and it was already leaking before i changed the carburetor. everything works fine other than the leak. what steps do i do or should i just let it leak? Thanks 

It's not a leak it is unburnt fuel oil, probably because you are leaving it on high idle while cutting under low load rather than modulating the power as required. As the revs hit the limiter the spark cuts out so fuel doesn't get burned and goes out the exhaust.

[LucH]

1 hour ago, Dan Maynard said:

Is it 2 stroke oil? What ratio do you mix your fuel?

50:1 pre mixed fuel 

[LucH]

55 minutes ago, pleasant said:

Either been run for sometime previously on an oil rich mix and the muffler is partially clogged so not getting hot enough to burn the excess oil off, or you are currently running a very rich mix and that is the excess oil in the vapour.

 

And when you say you have torched the muffler, did that entail actually removing it and getting it red hot all round? Whilst you had it off  did you check/clean or remove the spark arrestor (if fitted)

Yes i did remove the muffler but never get it to red hot and no spark arrestor installed

[LucH]

32 minutes ago, openspaceman said:

It's not a leak it is unburnt fuel oil, probably because you are leaving it on high idle while cutting under low load rather than modulating the power as required. As the revs hit the limiter the spark cuts out so fuel doesn't get burned and goes out the exhaust.

What should i do to fix this? 

[GarethM]

Drive it like you stole it, or get a smaller model.