1974 Evinrude 50hp - Idle Problem

[Kiwi]

I've owned this motor for a couple of years now and it has never idled all that well. When you engage forward you have to quickly increase the throttle before it stalls. Particularly frustrating when your trying to get it back on the trailer on a windy day ! Today I discovered something that if I trim it up until the prop is just under the water it seems to idle quite well, if I lower it so its basically straight up and down then it stalls. Once it reaches 2500rpm it is incredibly smooth, but below that and especially at idle it is somewhat rough. Does anyone have any idea why when tilted it runs much smoother at idle ? I haven't dismantled the carbs at all for fear that I may make things worse. If I was to overhaul the carbs, firstly is there a kit ? and secondly is it something I can tackle myself I am quite mechanically minded and have a workshop manual.

Thanks

 

[bigheaded5]

Re: 1974 Evinrude 50hp - Idle Problem

There will be a LOT better advice from more qualified than I, but I relate to your post. I recently picked up a motor for a boat I was selling and needed to get it running. It was a 80 HP Merc that ran like garbage and would not idle. Limited motor experience here, but I slowly took off the carbs, on a work bench I removed everything I could and cleaned it with compressed air and carb cleaner. I was able to salvage the gaskets so I put it back on with no new parts ( I KNOW there is a rebuild kit). the motor purred, I adjusted the idle screw and it ran great..idle and going into gear smooth and high rpm. I told the new owner the carbs could use a proper rebuild when he gets a chance.

my point is....Like you, I'm handy...can figure my way through most things...with a manual even better. There arent many parts to it, just watch the needle and work on a clean work surface with a rag to place the lose parts on. Its not too complicated of a job....it was harder getting to them than doing the actual tear down, but even that wasnt all THAT bad.

In taking the carbs off, it gave me a better view of things and I noticed a couple fuel lines that needed replacing. I replaced everything with FUEL TUBING and SS clamps along with a new fuel filter. I also changed the water pump...I was nervous, but a VERY simple job. Just be mindful of the direction the flaps are facing on the old pump so you can replace it in the proper direction with the new one.

YOU TUBE is a great tool to WATCH someone else actually do it.

 

[Kiwi]

Re: 1974 Evinrude 50hp - Idle Problem

Thanks Bighead, I'm starting to build confidence already ! I've done a water pump on a Merc 50 some years back. You Tube is a great idea I hadn't thought of that. I'll do some more investigating regarding a rebuild kit. To be honest my local OMC dealer isn't that interested in engines of this age so hopefully I can get something online. If someone has some info there would be great. Cheers