1969 Evinrude motor idling help

[coralman]

I have a hard time getting the idle down low enough every time I try to shift out of neutral into either reverse or forward. The motor will cut out. I am wondering if it has to do with buildup where the gas enters the combustion chamber. When I cut it down too much it can't maintain enough gas to keep the motor running (or so it seems). Can you safely add gas treatment carburetor cleaner to the fuel tank and run the outboard on it to try and clean it out a bit? If so, how much is safe and is there any suggested brand? All the automotive ones I find say to add the entire bottle ( which I know wouldn't be good in a 6 gallon tank).

 

[Dabbler_E]

If I understand the question, the problem is the reducing the throttle low enough to shift causes the motor to stall -- is that correct?

There are several possible causes, none of which is likely to be solved by adding a fuel treatment.

What is the horsepower or model # of your motor?

 

[coralman]

That is correct. I can sometimes get it low enough to shift, but many times it won't or it just barely shifts into forward or reverse and then will drop back out into neutral.
It is a 25 HP, model 25902.
This is the repair manual for it (haven't had the money to purchase it yet).

http://www.iboats.com/1969-Evinrude...5071106--session_id.849294617--view_id.439227

 

[Dabbler_E]

Is this a motor that you have just gotten and are trying to get running right? Or is it one that used to run well but now is giving you problems?

Two really quick & cheap things you can do to learn about the problem are to look at the plugs and check for spark. You can get a spark tester at any autoparts store for 5-10 bucks. You should be able to get a strong blue spark over at least a 1/2 inch gap on each cylinder. Check the spark plug gaps, and compare their appearance to a chart like http://www.aa1car.com/library/reading_spark_plugs.jpg

For instance, it could be that one cylinder is not firing, and you'd see one wet plug and one normal looking one. If you have no spark to that cylinder, you've narrowed down the problem. If there is spark to both but one plug is wet, that would suggest poor compression in that cylinder, and you'd want to get a compression gauge to confirm.

Let us know what you learn from the plugs & spark check.

 

[Dabbler_E]

Oh, and I just re-read your last post, and it sounds like you have two problems: poor idling AND failure to stay in gear. Is that true?

 

[coralman]

I have had the motor for a long time (was my grandfathers before I inherited it). It sat in storage for the last 5 years. I have never had issues with it before this year. I cleaned up the parts in the bottom gear case and replaced all the gaskets in the the bottom gear case as well. Afterwards I filled it up with outboard gear case oil I got from a boat dealership. I filled it until it started coming out the top oil level hole.
If I can get the idle down low enough I can get a good shift and it stays in gear then it runs fine. The problem is getting it low enough to fully engage it in forward or reverse, without the motor cutting out. I can tell if it isn't fully in gear as you can feel it bouncing a little. If that happens I quickly move the shift handle on the side of the motor back to neutral then try to adjust the throttle and shift again until I get it. Once it is running and I don't decrease the the gas flow too much it runs fine.
I can check the spark as I do have a spark tester I use for doing car engine work and I also have a compression tester.


Thanks,

 

[flyingscott]

You probably need to rebuild and clean the carb after sitting for 5 years. I personally like to take the carb off and go through it that way I know it gets all brand new gaskets. Also get a good aerosol carb cleaner and use an air compressor to blow out all the passages

 

[oldboat1]

To find your posts, just click on your user name after logging in (or the down arrow in the log in box, after sign in). Lots of questions. You might start by getting it running in neutral, and and let it warm up at idle. Get it running smoothly -- don't know what you mean by "decrease gas flow", but think you might be adjusting the top needle on the carburetor -- which would be right. Turn it clockwise until the motor starts to miss, then back it out about a quarter of a turn. The adjustments are very slight on that needle -- 1/8 turn, then wait for the engine to catch up. Don't know what is meant by "bouncing", but if you did that gearcase work you might have gotten the shift rod out of adjustment -- seem to have a shifting issue if you can't get it "fully in gear". Don't put anything in the fuel tank other than fresh 2-cycle oil (50:1), and make sure there is water coming out of the leg while running. If it smells hot or is too hot to touch, shut it down.

much more. Keep trying and listers will respond to what your describe. The motor is apparently running, so it's got a chance.

 

[coralman]

Thanks for the help. I will do that. I have seen the exploded view and it doesn't look all that complicated. I just had to rebuild my Minkota trolling motor switch since they don't make my model anymore. If it isn't car and truck motors then its boat motors.

 

[coralman]

oldboat1 - your response must have posted few minutes after my last one, even though the time shows 2 minutes prior to mine, as it was not there when I last posted.
Thanks for the tips on finding my posts, very helpful. Beats scrolling thru everything.
I actually have not touched the needle on top of the carburetor yet. I was just using the throttle adjustment on the tiller handle.
As for the bouncing statement. It is very faint but if I am holding onto the forward/reverse shift handle on the side of the motor, I can feel a sort of bouncing sensation of the handle and either it will go into gear fully, or it will some what engage but then drop back out into neutral. If I manage to get the throttle on the tiller turned down low enough without stalling, I can put it into gear and it stays put and runs great.
When I put the gear case back together, it seemed to only go back together one way. I had taken a photo of it prior to removing any components inside just in case, and it looked the same as the photo after reassembly. Water does come out of the leg with good force so I know the water pump is working good.
I will try everyone's suggestions and with any luck It will be back to how well I remember it working.