Stihl HS76 engine runs flat

[Carl358]

Hi, I have a Stihl HS76 hedge trimmer, it runs and ticks over fine, but when you come to rev it, it’s slow, and only revs slightly higher than tick over but sounds really flat.

I tried to adjust the carb but no luck, new carb kit bought, noticed a chip out of a part of it so brand new carb bought and fitted. Same issue.

Compression i thought, removed spark plug which virtually fell out, so just fitted a new thread to it (helicoil) fitted nicely, new plug too. Same issue after trying to set up the carb but just doesn’t seem to want to have any guts to it. Compression is fine too, I’m nearly at a loss!! Anyone any other ideas???

[Carl358]

Oh, fitted a new air filter too, have noticed it does spit out a little bit of fuel from the air intake, would that be anything?

[lurkalot]

Blocked exhaust perhaps.  Check muffler and exhaust port.

[Carl358]

20 hours ago, lurkalot said:

Blocked exhaust perhaps.  Check muffler and exhaust port.

Just cleaned out the exhaust muffler and Boom!! Purring like a kitten now! Didn’t even think of that one!! Every day’s a school day! Thanks lurkalot, much appreciated!!