1961 Johnson 10 hp carb setup

[BMarlin]

Hi,
I recently rebuilt the carb on my QD-22 and am currently tuning it. I set the low speed needle to 1 1/2 turns out and the high speed 3/4 turns out per the Seloc manual. I got it to run fairly well with these settings but it seems to run better the leaner I get it in the high speed. What would be considered too lean? The RPM climbs as I turn it leaner all the way to the stop without a falloff. For the low speed setting, it seems a bit rich and misfires at anything below the "Shift" position on the throttle. I think it might be loading up on fuel then stalling but I don't know. Any help on these matters would be greatly appreciated.

BMarlin

 

[wbeaton]

Re: 1961 Johnson 10 hp carb setup

Those are only starting positions. Put the motor on your boat and go for a ride. The carb needs to be set with the motor under load. Run WOT and set the high speed needle until you get the best (fastest) performance then back the needle out an 1/8 of a turn or so. This will keep it from being too lean at WOT. Then run the motor down to idle and do the same.

 

[BMarlin]

Re: 1961 Johnson 10 hp carb setup

Thanks! When I tested it out we were on the water so we'll head back out. When I turned adjustment knobs on the front of the motor, I hit the lean stops for both the high and low speed needles and the RPM was still climbing. I'll try it again using just the needles then put the knobs back on. Would being too rich in the low RPM range cause it to backfire and stall?

 

[wbeaton]

Re: 1961 Johnson 10 hp carb setup

If its too rich it will run rough. Too lean and you get a sneeze (backfire). The high speed jet effects the mid to high range running of the motor. The low speed jet is for slow speed and idle adjustment only.