2000 Johnson 60 very fast idle

[Twin_Vee]

after searching on here, it seems i have the opposite problem of most...

bought my first boat / motor and it starts up and runs fine but... it idles at 2400 rpm!!!

got the Selco manual and went through the linkage... thermostat... looked at the timing but can't really be checked at 2400 rpm. used some starting fluid to check for leaks around the head to no avail...

where / what should i look for to cure this problem since i don't think it's a good idea to use the boat with such a high idle.

thanks in advance!!!!!!!!

 

[petryshyn]

Re: 2000 Johnson 60 very fast idle

have you checked to see if all carb throttle valves are completely closed at idle?

 

[Twin_Vee]

Re: 2000 Johnson 60 very fast idle

yes. as part of going through the linkage, i verified that all butterflies are in the closed position.

 

[tashasdaddy]

Re: 2000 Johnson 60 very fast idle

linc n sinc. idle speed adjustment, cables mis-adjusted.

 

[petryshyn]

Re: 2000 Johnson 60 very fast idle

check the timing when attempting to idle. This will give a clue to whether its a linkage issue or air/fuel.....

 

[Rick.]

Re: 2000 Johnson 60 very fast idle

check the timing when attempting to idle. This will give a clue to whether its a linkage issue or air/fuel.....

I'm watching this thread for personal reasons. (I'm having the same issue with my 1995 40HP Johnson) Could you explain how you would know by checking the timing if the problem is air/fuel or linkage? Thanks, Rick.

 

[petryshyn]

Re: 2000 Johnson 60 very fast idle

You can expect the timing at idle to be somewhere between 5 BTDC to 5 ATDC depending on the model . If it is up much higher than that, it could cause too high an idle speed. If the timing is high (like 10 BTDC+), then its likely the cause of the high idle. This could be the result of maladjusted link/synch or a defective quickstart system (pack, sensor, wiring) if so equipped.
If its not high, the engine is getting too much air/fuel from somewhere:

-open throttle plate or plates
-leak in idle circuitry
-leaking intake gasket

 

[Twin_Vee]

Re: 2000 Johnson 60 very fast idle

after checking and double checking, the only thing that helped was adjusting the A / F screws. still needs some tweaking as well as the timing but hey, much better than it was!!!!!!