1970 25 hp sportster (25002C)

[D_Loomis]

I recently acquired a stick steer jon boat with a 1970 evinrude 25 hp Sportster outboard model 25002C. Finally got a chance to mess with it, new gas etc. and it started on the third pull, however it took off revving really high. how do I adjust the idle? The guy I got it from stored it in a climate contolled storage, and ran it a couple of year ago, he also had it tuned up just prior to running it. All thje cables and stuff seem fine but the throttle control didnt slow it down much when I backed it off(simplex). I disconnected the throttle control cable and tried it again, and it did the same thing.

 

[kodibass]

Re: 1970 25 hp sportster (25002C)

Just above the carburetor you will find a small roller, it controls the butterfly on the carb via a small link rod, as the throttle is advanced there is a cam plate that advances this roller, when in the slow/idle position make sure the roller lines up with the mark on the cam plate. make sure that the choke linkage on the side of the carb lets the choke butterfly return fully open after the motor starts. sounds like some part of the linkage is sticking and just needs freeing up and a bit of light lubrication.

 

[F_R]

Re: 1970 25 hp sportster (25002C)

As you tried, first disconnect the cable. Then look at the throttle gears on the port side (left, looking forward). See that plastic screw with a spring around it? That is the idle speed adjusting screw. Back it off to bring the idle speed down. To clarify, that screw limits how far you can move the throttle toward "slow".

Once you are satisfied with the idle speed, reconnect the cable. If the Simplex control won't bring it down to the speed you just set, there is a similar idle speed adjustment on the forward end of the control box.

Summing up, adjust the motor first, then the control, if necessary.

 

[D_Loomis]

Re: 1970 25 hp sportster (25002C)

Thanks guys. Something, a jet maybe?, must have been stuck. I tried it this morning, and it started up after a couple pulls and purred like a kitten. With no adjustments at all. It's a great running motor. It wouldn't go in gear, then I realized the hub was spinning and the prop wasn't. I replaced the broken shear pin and it operates perfectly. Thanks again. This forum is awesome.