johnson 40 low power

[radiosau]

i am only new in here but i have a johnson 40hp not sure of the year but modle number is 40RL75C when i get to 1|2 throdle i loose power and it is as if it starts to flood if i take the throdle back a bit it runs ok but not getting full rmp out of the motor is there anyone out there that can email me some manual pagers on the tune up on this motor or any info anyone can give me would be great<br />many thanks aaron <br /> radios@austarnet.com.au

 

[petryshyn]

Re: johnson 40 low power

hey wally!!<br />does she have a main mixture screw?<br />sounds like she's running lean at top end. next time out, open throttle wide open and continue to squeeze the primer ball keeping it hard. does this help? if it does then its a fuel supply issue...fuel filter, fuel pump, tank vent, carb main jet plugged etc.<br /><br />good luck!<br />

 

[radiosau]

Re: johnson 40 low power

thanks for that i cant find a mixture screw anywere on the carb but i did notice that the butterfly in the carb at full throdle was only 7\8 open could this be the problem are there any other carb screws in this moter that you know of i cant seem to find any of them.<br /> radios@austranet.com.au

 

[JB]

Re: johnson 40 low power

Ahoy, Wally1. <br /><br />I think Schematic has you on the right track.<br /><br />You really need to invest in a manual. You are obviously willing to work on the engine yourself and, even better, willing to ask for advice. With a manual you would be "home free"! <br /><br />I don't know the number, but the Clymer manual that covers your engine is only about $35.<br /><br />Good luck.<br /><br />Red sky at night. . .<br />JB