My OS 1.60 FX is hard to start. I have it mounted inverted in a Chipmunk using 5% Nitro fuel and an OS #8 plug. I know I have hot ignition and even after priming the carb, it is slow to start. Starting inverted helps it a little, but it still doesn't start easily. I am using an electric starter and sometimes I start by hand. HELP!![]

After you fuel the engine, open the carb half-way....put you finger over the exhaust
outlet....and spin the engine over for a few seconds with the electric starter.

After a good "prime" like that, the engine will start instantly when you hook up
the glow and spin it again. Most times, after a good prime like that, you can back-flip
the prop by hand and start it.

FBD.

I have a side mounted O.S. 1.60 with a perry pump. My starting ritual is as follows.

1.Open carb fully.
2.Plug carb with my finger and flip prop until I feel fuel on my fingertip (about 5 flips).
3.Close carb completely, flip through compression 5 times.
4.Open carb about 15-20% and flip back-wards against compression.

It is rare that the engine does not start on the first back flip. A different setup might require different voodoo. This works great for me.

Scott.