There is a tiny passage from the bowl up to the low speed needle, if it is clogged it will not idle. You have to take the carb apart and run a wire up it to make sure. Set both screws by distance out from seated not by number as knobs can be removed and replaced in any position. Start at 3/4 turn out and go from there, probably will leaner when you are done which is in.
Thank you very much for your answer. We are newbies at this so your expertise is much appreciated. Our motor came with the boat and was (per the seller) made only one year, 1956, model/serial number 25022. If you have any more ideas, we sure could use the help!
The high speed and idle jet positions are not set in stone. They are a [STARTING] reference point. They are made to adjust ideal mixture ratio. So the " one" turn can be adjusted either way. The idle "speed" is set by moving a set screw on the carb linkage. This in turn moves the throttle plate open. It's late and I don't have my manuals out,,but follow the linkage from the carb back..My big 40's have it on the input bell crank on the outside of the cowl back by where the throttle cable snaps in. Here this might help. This guy says he isn't a mechanic ,,but I think he knows his way around. I don't know what series 30 you may have. Good luck.
sounds like the low speed jet may be plugged up with gunk , a vacuum leak causing lean out or the timing is not adjusted properly for idle
try some seafoam marine cleaner in the tank to see if that helps clean it out
How do you set this motor to idle while at the dock - motor starts fine, runs great at high speed but will not idle from start up or back from high speed. Have followed instructions, set low speed knob to 1, high speed knob to 3 for start up, but motor dies out when put in neutral. All we can do is start it and quickly go into forward to run this motor. Thanks