What are the pros and cons of idle bars. I'm having a little bit of a prob getting a OS SF 46( non-ringed) to go from fast idle to wfo. This was a motor I bought from an individual, was gummed up real bad. Complete tear down, everything looks great, really good compression, starts great. Just wondering if idle bars make it more difficult to set-up.
Yes, I am new to this, but am a very capable mechanic.

Whats ya'll thoughts? Thanks inadvance for all info.[8D]

Idle bars are NOT needed. Most likely the cause of poor transition from low to high throttle is idle needle is not set right,or it could be old fuel or a bad glow plug. If you know you have good fuel and a good glow plug try setting the idle needle in 1/8 turn at a time clockwise. If transition gets worse try turning it counterclockwise until you get a good transition. Goog luck!

The idle bars were developed for the loop scavenged engines with a baffled piston.

Your SF is a Schnerle ported engine. They don't normally use a idle bar plug.

Enjoy,

jim

Another disadvantage it if the bar is welded to the plug it could separate and destroy your engine. I never use them.

But Gentlemen,if one have to use engine inverted,it is said idle bar plug has big advantage on idling.

I had the same problem with my 46 sf I was using the OS 8 plug and it would just die as soon as it made the transition from the low speed needle to the high I switched to the Fox RC long and it's been running fine ever since.