gavinlewis

I have an FS 120 which although it runs very well, will only idle on glow heat. However if I lean it out even an 1/8th of a turn from where it is on low end it dies. Much the same thing when going richer, is there any benefit to running a hotter plug, or more nitro?

I am running 15%, but have considered 20 as I run it in a couple other engines anyway, and would like to consolidate fuels.

Bax

My Feedback: (11)

If you have a pumped version of the FS-120, then please see this FAQ on its setting:

http://www.osengines.com/faq/faq-pumped.html

If it's the non-pumped engine, then you may need to look at how much use the engine's had, and whether it's getting worn out if it's been around a while. If it's fairly new, then it may need more breakin time. We usually break in a 4-stroke engine by running it at rich as possible at full throttle for at least 15-20 minutes before we even begin to lean the high-speed needle. We'll have about an hour's worth of running time at full throttle before we begin to work on the idle mixture. We want the ring and valves to get fairly-well seated before we start the low-RPM setting process.