Evinrude 18 HP throttle shaft holes worn

[CedarRiverScooter]

Hey Pappy & everyone - I have rebuilt the carb on my '72 18 HP 'rude & it still does not want to idle down with throttle plate closed. It does respond to low speed needle adjustments, but I have to keep the plate cracked to keep it going. I don't have a tach but can't get down to a normal idle.

I took carb apart again & now I see that the throttle shaft has about .008 inch of play. I am thinking this is letting unmetered air in.

Is this a correct assumption?

Can the carb body be bushed or am I shopping for a new carb?

Thanks

 

[Pappy]

I have heard of the throttle main body being bushed but for the price of doing that I would bet you can buy a couple of carburetors on the used market and install your kit in them.
If you start looking I would look as far North as you can since they do not have the normal boating season. The carbs should have less wear.

 

[CedarRiverScooter]

Thanks!

 

[RaisedByWolves]

.008 isint really the kind of play I would worry about given your issues.

Pack the ends of the shaft with some thick grease and see if there is any difference.

 

[CedarRiverScooter]

Update - I measure things more closely & found shaft more worn than the holes. Got a new shaft on order so that should fix it good enough.

But I think RBW is right & that is not the problem.

I was checking the throttle linkage & noticed the points plate moving up & down when rotating.

So I took it apart & found the threaded reainer ring (for points plate ) was upside down. I think this explains why the throttle movement was not smooth.

But wait, there's more!

While fixing that, I notice that the points cam was twisted past the key. Maybe that's the problem.

Fortunately I have a parts motor that had a useable cam.

What I am wondering is what caused the cam to wear so badly?

 

[Shaugh]

I've done the same thing... just seems like that ring should be turned with the tapered side up..... :wink:

That damage to the cam is very unusual... never seen that before...something got seriously jammed up there.... can't imagine that happening during normal wear... I'd be on the lookout for other damaged parts... most likely somebody failed to line it up right before they tightened the flywheel down ?

 

[CedarRiverScooter]

Got it back together today. The key was a bugger to get out, I think they super glued it in. Got one from ACE hdw & filed it to fit.

Lesson learned here, don't buy a non-running outboard.

 

[RaisedByWolves]

That’s really odd.

I buy non runners all the time and turn them into runners.

 

[CedarRiverScooter]

Got it started in my test wastebasket today. Now I can get it to idle, but only for about 30 seconds at a time. Starts right back up with throttle. I haven't done anything with fuel pump, so that is my next move. Also suspicious of the 60 YO fuel tank hose connections.