Stihl FS-80 losing power

Owenw

After singing the praises of Stihl tools in the previous thread my 10 yr old FS-80 strimmer has started acting up.

I warm up the engine and after 15-20 mins of use it starts losing power. If I give it more throttle it continues to struggles and (unless I ease off) cuts out. Then it works for a few seconds, then the power drops off again.

I'd be very grateful if anyone one knows what could be wrong.

danjo

I would change the spark plug if you have'nt done so.
Check it and see if it is sooting up. Maybe a clean with a wire brush and check the gap.

gsxr1

im not a strimer expert but race 2 strokes motorcycles .

You should start with the basics. Old petrol change. Over haul the carb , clean the float bowl and main jet, Check the float level . Sounds like ya might be losing compression and need a new piston and rings. After 10 years use you did ok on the one piston. I change mine ever 50 hours use.

Forgot to agree about the spark plug change.

Owenw

Thanks for the replies. Just changed the plug (looks like it was the original judging by the carbon buildup). Took 10+ pulls to get it going from cold. Will try warming it up and see if it loses power again.

TBH I don't know anything about engine overhauling. Can anyone recommend a 2-stroke expert in the kildare / wicklow area?

Yeah I'm more than happy with the performance seeing as its had little or no maintenance until recently.

gsxr1

Owenw wrote: »

Thanks for the replies. Just changed the plug (looks like it was the original judging by the carbon buildup). Took 10+ pulls to get it going from cold. Will try warming it up and see if it loses power again.

TBH I don't know anything about engine overhauling. Can anyone recommend a 2-stroke expert in the kildare / wicklow area?

Yeah I'm more than happy with the performance seeing as its had little or no maintenance until recently.

I guess the yellow pages.

there is a stilhl service shop in Naas. From sallins direction go to the main tee junction at the other end and take a right toward Time night club and B&Q. He is 20meters past the lights. Its also a bicycle shop.

Also before you do that. Clean the air filter. It could be blocked, making it run rich and fouling the plug. simple check.

Owenw

Thanks gsxr1.

Air filter is ok, replaced it last month & cleaned it 2 weeks ago. Machine has only been used for maybe 2 hours max since then.

I was only in that shop in Naas the other day - the guy was sound, but he only services what he sells.

Had less than stellar service from the dealer who we bought it from. so would prefer not to go back there.

Golden pages time...

kwacker84

I would say check the compression! If its 10 years old, change the piston, give it a good service and keep it fresh, it'll go for another 10 then!

If you want it rebuilt, i can do it for you if you want. I build my own chainsaws which are all Stihl's.