1975 Evinrude 50hp won't idle in gear

[Jacob645]

I've done a good bit of work on this motor to get it going. Brand new coils, fuel pump, tank, and fuel lines. The coils solved the first problem I had with it which was that it wouldn't go over about seven mph. It will now run fast all day long, but when you bring it down from WOT and try to run at midspeed it dies. Usually its the worst when trying to take off. When you put it in gear and try to go to WOT it will sputter out and die. Finally I usually wind up raising the RPMs with the idle lever and while they're still up i throw it in gear and it will take the gas. It works but i know its probably not good! Is there an idle speed adjustment somewhere where i could raise the idle speed?

 

[samo_ott]

Re: 1975 Evinrude 50hp won't idle in gear

Sounds like a dirty carb. A rebuild solves most issues.

 

[Jacob645]

Re: 1975 Evinrude 50hp won't idle in gear

My dad and I just rebuilt the carbs about three months ago, and they were in pristine condition when we took them off. Compression is 120 on both cylinders.

 

[HighTrim]

Re: 1975 Evinrude 50hp won't idle in gear

Does sound like dirty carbs, or a fuel restriction.

Check to see if the timer base (starboard side, under the edge of the flywheel, linked to the throttle lever) moves smoothly without sticking when you advance the throttle.

Take the airbox cover off & observe whether the throttle plates are parallel.

Also, the timer base should start it's travel before the throttle plates start to open, or else she'll fall flat when you try to accelerate.

 

[tashasdaddy]

Re: 1975 Evinrude 50hp won't idle in gear

you need a OEM manual and due a link n sinc. this coordinates the spark and the fuel so they work at the same time. also check your linkage for any slop, it could be that it is getting gas before spark, thus flooding it.

 

[wavrider]

Re: 1975 Evinrude 50hp won't idle in gear

I had the same problem with an 33hp, I actually took the carbs apart on several occasions and they looked clean. Re-cleaned them with carb cleaner and put it back together, it would run on WOT, and in mid range but not idle worth a rip.

After recieveing some great advice from this site I tore into them again, and cleaned as per instructions from this site. " Use a soaking chemical, clean jets thouroughly, remove jets of possible, requires a tool that can be made from a good straight slot screwdriver, use compressed air and pipe cleaners through every orfice and jet to ensure cleanliness, assemble and install carb, do a link n sync as per manual instructions."

I followed those instructions to the letter, the 33hp runs great and idles better than it ever has. My carb looked clean every time I removed and disassembled it. The real proof is in the performance.

After you get it running correctly do a de-carb, It greatly improved my performance all around and you wil havethe peace of mind knowing your emgine is clean of carbon build up. Good luck and keep posting results,WAV.

 

[Jacob645]

Re: 1975 Evinrude 50hp won't idle in gear

Thanks for all the replies so soon! I really think that it has something to do with the spark advance. So the spark advance should move first, then the butterflies open right? Any ideas on where to order the best manual for this motor?

 

[tashasdaddy]

Re: 1975 Evinrude 50hp won't idle in gear

the best manual is the OEM reprint, available at outboardbooks.com. get the number, and you may get lucky on ebay.

 

[Jacob645]

Re: 1975 Evinrude 50hp won't idle in gear

Ok so i just went out and looked at the linkage and the timer base doesn't move at all until almost full throttle. Is that right? There isn't a constant movement from low speed to WOT.

 

[tashasdaddy]

Re: 1975 Evinrude 50hp won't idle in gear

no that is not right. but it should idle, i think you have 2 problems. link n sinc, and dirty carbs. plus the impeller. you do need an OEM manual.

 

[ezeke]

Re: 1975 Evinrude 50hp won't idle in gear

The arm on the timer base has a mechanical link when the throttle is advaced. Is it connected?

 

[Jacob645]

Re: 1975 Evinrude 50hp won't idle in gear

Here's some video of my linkage! I took this by myself, sorry if there's no sweet camera angles...


http://youtube.com/watch?v=S9ryBVGlATo

 

[Jacob645]

Re: 1975 Evinrude 50hp won't idle in gear

Here are a couple of pictures
First is in idle
second is at WOT

 

[HighTrim]

Re: 1975 Evinrude 50hp won't idle in gear

You have some adjusting to do.

I would get yourself a factory OEM manual, they will go over the steps for you with diagrams and pics.

They will pay for themselves a million times over.

 

[kennyk]

Re: 1975 Evinrude 50hp won't idle in gear

It looks like your timing lever or base is hanging up and not moving freely. Disconnect the link rod at the top that goes to the timer base and see if it moves easily towards the full WOT timing stop by hand. Mine was doing the same thing and it was the wiring harness coming down from the timer base or stator? that was preventing the smooth movement. I asked my dealer mechanic if he comes across this much and he said quite a bit, even from the factory new they make the harness too tight that prevents the timer from moving freely. Ken

 

[tashasdaddy]

Re: 1975 Evinrude 50hp won't idle in gear

all the above.

 

[Jacob645]

Re: 1975 Evinrude 50hp won't idle in gear

just lake tested this quick fix. it works!

 

[kennyk]

Re: 1975 Evinrude 50hp won't idle in gear

Happy the quick fix worked now when you get time you can figure out what is causing the problem. Three possibles come to mind. One the tight wiring harness that prevents normal travel, two the timer base is dry or the clamps holding it down are too tight and three the advance arm bushing itself is dry and in need of lubrication. After having the same problem with my motor when I read so many messages relating to poor performance I wonder if some also have a restricted timing advance. This would be discovered while doing the "link and sync" that is always highly recommended while troubleshooting. Ken

 

[kennyk]

Re: 1975 Evinrude 50hp won't idle in gear

Just thought of a fourth, the arm has a spring around the bushing that could be broken or very weak. Ken

 

[Jacob645]

Re: 1975 Evinrude 50hp won't idle in gear

I'm leaning toward the spring myself, along with some sync and link problems! thanks for all the advice guys!