89 evinrude 60 hp idle racing in neutral

[Cat nip]

Yesterday on the river I got to the first fishing spot and when I put it in neutral to set the anchor the idle was at 300 rpm. Seemed to be ok in gear and was running fine but never got past half throttle because it was a new streach of river for me and the water was high and fast with lumber . Did this all day and never had a problem before. Started it in a tank today and its still at 3000 rpm. Throttle plates all fully closed, no vacuum leaks that I can find, pumping fuel bulb dosent seem to make a difference. If I smother the upper carbs one at a time with my hand it slows way down and will die but when I cover the bottom carb there is no change. I took the carb off and cleaned it with no change. It is getting fuel to all 3 carbs. I cant get my compression tester till tomorrow. Any ideas?

 

[ob]

Try pumping the primer bulb with engine not running and see if it pumps up firm and holds. If it doesn't it could indicate one or more carburetor floats are stuck or the fuel primer is leaking fuel by. Also insure that the red lever of the fuel primer solenoid is closed as would be indicated by the lever being seated clockwise and inline with the body of the solenoid. Also check and insure that the timer base arm is all the way to the idle stop and not stuck near the wide open throttle timing stop screw.Timer arm should move freely along its travel by hand.

You mentioned that the throttle plates are all fully closed which should indicate that the throttle linkage roller is aligned with the scribe mark of the fiber cam and just barely touching. Is this the case?

 

[flyingscott]

Check the throttle cable to make sure it is pulling the linkages back against the idle screw and make sure the timer base is retarding correctly.. Then check the trunion nut on the cable is still holding could be stripped

 

[Cat nip]

Thanks for the quick response fellas. The roller is aligned with the mark and there's about .0003 clearance between the roller and cam so not binding there. The timer base arm is in the idle position. The throttle linkage is against the idle screw. When I tried pumping the primer bulbs it would not get firm, so I got a new one and will pump up now. The lower carb was seeping a bit so thats when I took it apart and cleaned it . It still seeps some so I need a new needle and seat but wouldn't that make it run rich and slow the idle down a bit? The red lever on the primer solenoid is in line with the solenoid and pointed to the rear as it has always been.

 

[ob]

Only other thing I could think to check would be to insure all carb flange bolts are snug and not leaking by. I assume you removed the silencer cover to insure that all carb flaps were closed in neutral. Did you happen to push lightly on them to make sure the linkage screws that synch them had not come loose allowing any of them to swing freely? Past that I can't think of anything else that would cause your symptom.

 

[Cat nip]

All of the carb to intake flange bolts are tight as are the intake bolts. I pushed on the throttle plates with a screwdriver and they wont close any farther, I even pooped off the linkage rods and still no movement or change in idle speed. I installed new needle and seat and seemed to improve for about 10 minutes so I gave it some throttle a few times and then its back at 3 grand. With all the idle stops against the stop screws and timing arm at idle position. I have great spark but will check compression tonight as well as go over it again with somthing a bit more flammable than carb spray to try and find a vacuum leak again. The part that has me concerned is I can choke off the bottom cylinder and it has no effect on how its running at all.

 

[ob]

Definitely a strange scenario you have going on here. Sounds to either a vacuum leak as you suspect or somehow the idle timing has become way off from spec. Can you visibly see the timing arm idle adjust screw touching the engine block? Is it possible that the flywheel center magnet, like mine recently , has come un laminated from the flywheel hub? Mine of course ,never actually rotated off of its mark but I removed it by hand as it would slide up and down. Just trying to provide some food for thought.

 

[Cat nip]

I will look for that tonight when I get home when checking compression and for a vacuum leak again. Thanks again for more ideas.

 

[Cat nip]

Wrll compression is ok. I think I found a vacuum leak down at the bottom of the cowl, way down there . Maybe a lower crankshaft seal? I might bring the toon to work tomorrow and see if I can smoke check it?