New DIYer need advice

[htr2133]

Hi Everyone,

I have a 73 Johnson 6hp. I've been having issues w for some time but it was usable till this spring. Early this year, I couldn't get it to start. I haven't tried till this past week to get it running. I went Sat. and bought new plugs, and an OEM Fuel Hose Assembly. I have had nothing but issues out of the hoses and fittings bought at Walmart or sporting goods stores.

I took the boat out Sat. and tried for about 5 min. of cranking and gave up. It never even hit. Yesterday I put the motor in the tank and tried again where I could work on and inspect things better. After about 10 cranks it hit, then started, then ran fine. I got the idle rich/lean adjusted and it was running well in the tank. I even ran it in drive as high as I felt was safe. Turned it off, started it right up several times, no issues. Ran all the fuel out the carb and let it sit for 3 hrs, hooked it back up and it started on first pull. So, it seems to be running ok now.

Here is my ?s:

1. I noticed fuel spitting out of the back side of the fuel pump. It is not a crack, but a perfectly square port of some sort and it was a consistent spit of a drop of fuel coming out. Is that normal or is there something wrong with the fuel pump or carb possibly? If I had to guess, I would say a cup of fuel would come out in about 5-10 min. of idle.

2. The past couple of years I've been trying to figure out why the motor surges at top rpm. It is not a miss, just a slow down followed by a gain and that repeats every 15-30 seconds. It is very possible it could be fuel hose assembly I was using. I will know more now that I can get the motor to start next time I take it out. But, I did notice yesterday when the motor was in the tank that the little black arm that meets the roller to control speed has a fairly deep groove worn in it. I would say the groove is probably a 1/8 inch deep. That doesn't sound like a bunch, but I reached in and pulled the lever back to where it would be if it were flat and there was a definite change in the rpms. Could this be what is causing the motor to not reach and stay at full rpm? Also, is that lever adjustable?


Thanks for any info you can provide!

 

[AlTn]

Question 1...Sounds like the diaphragm has a hole in it if the fuel is leaking from the back, and a cup is BAD leak. Rebuild or replace that pump if you are certain that's the source of the leak. Leeroy's Rambling's has the rebuild instructions if you choose that route. Suggest you read them through before dismounting the pump and put a witness mark down the sides of the "layers" so you can at least be certain they are back together as they came apart, layer for layer.

Question 2. The "little black arm" is a cam follower part # 312832..replaceable, not adjustable. Kinda pricey. The surging may be caused by an air leak entering the fuel system from the fuel line, pump, fitting, etc.

 

[htr2133]

I think I can put some epoxy on the plate of the cam follower to level it back out and avoid the expense of the part

I don't think the fuel is coming from the back of the filter, it looks like it coming out of a small port on the filter. But either way, it sounds like there should be no fuel coming out there at all correct?

 

[racerone]

Pull flywheel and inspect coils for cracks.-----Very common problem.---------No fuel should be leaking from the pump.-------Check hose that goes from bottom to top of motor as well.

 

[Tim Frank]

and a cup is BAD leak.

....I'd add "dangerous".

 

[htr2133]

Thanks guys, I checked all the other hoses over really well and don't have any other leaks. I feel pretty confident replacing the fuel pump myself.

It has been suggested to me several times on here to pull the flywheel and check all the ignition parts. Is there a way I can check for good, strong spark with a spark tester without removing the flywheel? I ask because I am afraid to get in over my head and go from a poorly running motor to a non-running motor if I tear into the ignition stuff.

Thanks a ton for the help.

 

[Willyclay]

I have the Evinrude version of that same motor and it is a jewel. Hopefully, yours will be also. It is usually the simple stuff that causes these old beauties to run bad. Just be patient and troubleshoot it in steps and the experts here, which I am not, will guide you through any issues. The link below to a thread in the FAQ's tells how to easily check for a strong spark. Good luck!

http://forums.iboats.com/forum/engi...ked-questions-faq/162217-outboard-won-t-start

 

[htr2133]

Thanks, that is a good thread and gives me a good order of attack.

I took the boat to a local lake today and she started great but was still very slow to climb the rpm range. I ran the boat for a good 20 minutes at full throttle and it was still surging but never got on top like it should. I would say it ran most of the time at about 75% even though I'm holding at full throttle. I let it set and idle at the boat launch for another 10 min. and when I got back in to put it on the trailer, she ran right up on top and stayed there...until my fuel tank was empty.

Is it possible that there was just gunk in the high speed circuit that finally freed up? Can a motor literally fix itself just by running sometimes? I sure wish I hadn't run out of gas so I could know for sure if it was going to keep running like that.

Lastly, a local mechanic told me to run it like that and see if I could lay my hand on the head. He said if I could, the thermostat was bad and the motor was not reaching an ideal operating temp which would hinder performance. I can lay my hand on the head without getting burned at all really. I can find a hot spot but even it isn't so hot I can't leave my hand there for a second or two. What do you guys think; should I replace the thermostat too?

I figure until I replace the fuel pump that is leaking I can't really isolate any other issues, so I am going to do that for sure next. If after that it still isn't running out on top like it should without surging, I am going to rebuild the carb.

For now, I am just excited that the old girl is starting good and running at all!

Thanks again,

 

[Willyclay]

and when I got back in to put it on the trailer, she ran right up on top and stayed there...until my fuel tank was empty.

Does this mean you ran it at high RPM's in neutral? If so, the experts here warn against doing that because of the possibility of a runaway/dieseling motor that can only be stopped by blocking the carb throat with a rag. It can also self-destruct due to the "no-load condition" on the prop. If that is not what you meant, then my old geezer brain is scrambled again and confused.

What you are describing sure sounds like a motor that is running on one cylinder to me. To test, run it in neutral and idle speed then pull one spark plug wire off at a time and note how it responds. No change means that cylinder is dead. Bad idle or dies completely means that cylinder is good and the other cylinder is dead.

Try to get that fuel pump diaphragm replaced before anymore testing. IMHO, a gunked-up/clogged high-speed jet usually will not fix itself unless you added something like SeaFoam to the fuel. Hopefully, some other members will post in and offer more insight than me. Good luck!