Bigtim:

Yes, definitely check the valve/rocker gap. Excessive gap can make the idle sloppy, I think the Saito gap is set about 0.010 inch. You can get tools especially for Saito engines with the correct wrenches & gap gage, don't know about OS but I imagine you can tools also. Also make sure you are using the correct fuel. Saito's love 20% nitro, but Magnums require less to prevent detonation (check Tower or the OS website for recommendations). Use a castor-containing fuel.

Be sure you use a good plug that is not too old. OS four-stroke plugs are awesome, just make sure you don't have any buildup on the coil. Also be sure there is enough air flow around the engine to prevent overheating. And finally, make sure the centerline of your tank is near or SLIGHTLY above the centerline of your carb. If the tank is low, the engine will have trouble sucking fuel at low RPM.

N