# Stihl FS 85 off idle hesitation



## Cobrargc (Feb 15, 2009)

I replaced the Zama C1Q-S45 carb with a new Zama C1Q-S28. The S28 is listed as a replacement carb for the FS 85. The trimmer still has a hesitation off idle. The exhaust port is clean, but the trimmer does have better throttle response without the muffler. The muffler appears clean without any restrictions. The screen has been removed without much of a change. The trimmer has a fresh plug and fresh fuel. Before replacing the carb I ran a compression test and got about 90-95lbs. This should be acceptable, correct? The only other issue might be the mickey mouse set up Stihl uses to attach the plug wire to the terminal inside the boot. The wire just butts up against the wire terminal inside the boot. Could this be affecting the ignition performance? Any ideas?


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## geogrubb (Jul 28, 2006)

Cobrargc said:


> I replaced the Zama C1Q-S45 carb with a new Zama C1Q-S28. The S28 is listed as a replacement carb for the FS 85. The trimmer still has a hesitation off idle. The exhaust port is clean, but the trimmer does have better throttle response without the muffler. The muffler appears clean without any restrictions. The screen has been removed without much of a change. The trimmer has a fresh plug and fresh fuel. Before replacing the carb I ran a compression test and got about 90-95lbs. This should be acceptable, correct? The only other issue might be the mickey mouse set up Stihl uses to attach the plug wire to the terminal inside the boot. The wire just butts up against the wire terminal inside the boot. Could this be affecting the ignition performance? Any ideas?[/QUOT
> 
> While it is running spray/dribble some car/brake parts cleaner along the mating surfaces behind the carb, if the engine tempo changes you have an air leak, if not try opening the L jet about 1/4 turn. Have a good one. Geo


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## luckyvision (May 24, 2007)

incorrect on the wire terminal. the terminal should have a straight part off the 'coil' with a hook that pierces the insulation on the wire, the boot holds it all together..


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