Surging Johnson 6 hp.

[jitterbug127]

Try adjusting the slow speed needle counter-clockwise 1/8 turn. Repeat if still stalling (richer adjustment -- more fuel).

I started at 1 and 1/2 turns out and worked out from there. These 6 hp motors are normally pretty easy to get set, and they normally have really nice idles to them. This 6 hp motor seems to be stubborn, and not want to dial in for some reason. I sure it is user error, but not sure what i'm doing on this one to have issues.

 

[jitterbug127]

I have an idea, and let me know if this seems reasonable. My parents have a 1974 Evinrude fisherman with a carb that I rebuilt that idles flawlessly. I am thinking of taking the carb off that motor to see if my Johnson will run properly with a different carb on it.

 

[oldboat1]

not necessary yet, imo. Your low speed needle may be bent or broken off -- maybe with the broken tip in the carb housing. Pop off the domed cap on top and take a look.

 

[oldboat1]

Your pic shows it running at wot or close -- can't tell anything from that about low speed setting.

 

[jitterbug127]

not necessary yet, imo. Your low speed needle may be bent or broken off -- maybe with the broken tip in the carb housing. Pop off the domed cap on top and take a look.

are you referring to the welch plug?

 

[oldboat1]

To dial in a motor's low speed setting (or redial it in after, say, a carb cleaning, I usually start with the 1 1/2 setting, warm up the motor and get it to idle as slow as I can, then typically turn clockwise 1/8 turn at a time until it lean sneezes or stalls -- then back out the setting until it runs smoothly.

(^reference to the welch plug on top.)

 

[jitterbug127]

To dial in a motor's low speed setting (or redial it in after, say, a carb cleaning, I usually start with the 1 1/2 setting, warm up the motor and get it to idle as slow as I can, then typically turn clockwise 1/8 turn at a time until it lean sneezes or stalls -- then back out the setting until it runs smoothly.

you are phenomenal. Thanks for the advice!

 

[F_R]

Hurry out to a gun store and get yourself a bullet proof vest. You are going to need it w

 

[F_R]

Hurry out to a gun store and get yourself a bullet proof vest. You are going to need it when that thing explodes from over revving.

 

[Crosbyman]

swapping carbs could tell you a lot... good plan.

meantime did you check the vacum pull on the carb face with a simple piece of paper while a friend pulld the cord. you should feel it suck air with no back pressure coming out if reeds are ok..

if you spray fuel in the carb face and it keeps going you know it is a few flow problem. a different carb may prove it

 

[jitterbug127]

Hurry out to a gun store and get yourself a bullet proof vest. You are going to need it w

you are exactly right! and this was foolish on my part. I wanted you guys to see the issue I was having with the motor at full throttle. It was doing this last fall on the water underload. I had forgot about it until I tried firing it up the other day.

 

[jitterbug127]

I am 99.9% sure I got the issue resolved. It was the fuel pump.

For some reason both of the fuel pumps I had worked well on the 4 hp but not on the 6 hp. I tried starting the motor again and squeezed the ball just barely. It was like fuel pumps I've had that have failed in the past were you can completely squeeze the ball. this was like a tiny squeeze just enough to help the fuel pump keep going. It was like sort of working/ sort of not. Hard for my novice skills to tell. I have one more new Sierra fuel pump that I know is good that is on my 15. I put the Sierra fuel pump on and it worked perfectly fine. Motor idles really well for a good 15-20 minutes. I won't know if it is 100% fixed until I can get it out under a load behind my boat. Thanks for your help everyone as always!

 

[F_R]

I have a suspicion that the fuel pumps won't work properly at the extremely high RPM's you are turning. Never have tried it though, and probably never will.

 

[jitterbug127]

I have a suspicion that the fuel pumps won't work properly at the extremely high RPM's you are turning. Never have tried it though, and probably never will.

There is no reason to. You are absolutely right. This is a good learning moment for me. I didn't think running in a barrel at WOT was probably a great idea but I also didn't consider it to be a big deal. I have been educated to now know otherwise. Thank y'all for the insight.

 

[Willyclay]

It is usually the simple stuff! Glad to hear you whipped it.