johnson 3hp problems

[tatercats]

i have a 1957 johnson 3 hp. the carb is spotless, the plugs are good, but i dont know how old they are. they are champion j6j. it does leak a little fuel out of the carb, a gasket is leaking i think. the fuel is 24:1. it wont run fast. it seems to bog down and wont wind out. i have tried adjusting the lean/rich knob, but it doesnt help. it idles good, but could be better. i gapped the points at 020. please help.

 

[rickdb1boat]

Re: johnson 3hp problems

tatercats<br /><br />Have you removed the carb and cleaned it out? New carb kit? Points in good shape? No pitting? Spark plug is: 3HP 1952 - 1968 J6C Gapped at .030 Might try some new ones first.

 

[tatercats]

Re: johnson 3hp problems

i have taken the carb off and cleaned it a couple of times. it is spotless. the points are gapped right. i just got some new plugs for it. it does leak about 20 drops of gas out of the carb in 24 hours. could it be that it is sucking air? where can i find gaskets for it-model JW-14

 

[JB]

Re: johnson 3hp problems

Ahoy, Tatercats.<br /><br />The JW-14 calls for Champion J4C plugs, gapped at .030.<br /><br />You say the plugs are good. Does that mean that you have tested for spark to both cylinders?<br /><br />Have you verified that initial timing is correct and that the linkage between throttle and stator is fully advancing the magneto when the throttle is full open?<br /><br />You keep saying that the carb is spotless. It isn't spots that cause trouble, it is gum in the jets and orifices. Have you soaked it in carb cleaner and blown out those passages? Is the float level set according to the book?<br /><br />Let us know.

 

[tatercats]

Re: johnson 3hp problems

yeah-the carb is clean/gum free. all the jets are gum free. it has spark in both cylinders. the plugs i just bought are j4c-but havent tried them yet. it ran at high speed just before it ran out of gas-very lean.

 

[JB]

Re: johnson 3hp problems

AHA!! It leaned out to high revs when it was running out of gas, huh?<br /><br />You have too much gas getting to the engine. Could be the float level is too high, could be the float needle is not seating well, could be a bent high speed adjusting needle that doesn't lean it out adequately.<br /><br />Good luck.

 

[tatercats]

Re: johnson 3hp problems

thanks for the tips. where can i get gaskets for the carb at? i think the gasket for the bowl is leaking a little. or the carb to engine gasket is.

 

[rickdb1boat]

Re: johnson 3hp problems

I would contact these folks for parts info:<br /><br /> www.aomci.org

 

[rickdb1boat]

Re: johnson 3hp problems

Carb Parts:<br /><br /> web page # 439071