1969 Johnson 6hp

[Gridiron]

I posted a week or so ago about getting this ole' boy running. I was having trouble with starting. It would fire start to run then die. I rebuilt the carb. I even bought a service manual off of ebay to help me out. Got everything back together. Primed and choked a few pulls and it would barely start to turn over. Finially got it to go for a few seconds and died. Any suggestions? Could it be the fuel pump?

Thanks

 

[hunterhicks]

Re: 1969 Johnson 6hp

My 78 6hp is doing something like this too. I just ordered a manual off ebay as well, and am planning on doing the carb, plugs, and plug wires next week.

starts a little, then dies.

 

[ezeke]

Re: 1969 Johnson 6hp

Make sure the fuel pump is tight against the engine and that the gasket between the pump and the engine is in good condition and tight.

If you have an air leak anywhere along the fuel system, including the gasket on the carburetor, you could have a difficult time starting.

Basically, all the fuel pump does is lift the fuel from the tank to fill the float bowl at the bottom of the carburetor. The movement of the pistons pulls the fuel from there through the carburetor. Set your portable tank above the engine and let gravity fill the bowl, or have someone keep a little steady pressure on the primer bulb while you crank, then you will know if the fuel pump is part of the problem.

Some of the members here use a little pre-mix in a spray bottle to get the motors going. You could give that a try, but be careful.

 

[Gridiron]

Re: 1969 Johnson 6hp

I did put a inline fuel filter on the bulb hose. I did get a fairly large one. I wanted extra protection. Could I use starting fluid to help. Using very, very small amounts.

 

[F_R]

Re: 1969 Johnson 6hp

Listen up, a fuel pump hasn't got a dadgum thing to do with starting a motor!!!

You fill the carburetor with gas by squeezing the hose bulb. That is way more than enough gas to start the motor and it should run close to a minute with what's already in the carburetor. Well, half a minute anyway. It will start and run without even being connected to the fuel pump or tank, once you've filled the carburetor.

The fuel pump's responsibility is to keep the carb full after it starts running.

Get your eyes off the fuel system and look for the real trouble. Check the compression and spark. And remember, a spark jumping the gap of the plug laid against the head is not a spark test. It needs to jump a 1/4" gap.

 

[Gridiron]

Re: 1969 Johnson 6hp

Well mister testy I'm trying to find the problem. It has compression. Not sure if it is at spec. I'll need to get a guage. Plugs are new and gap to spec. jumps good.

 

[F_R]

Re: 1969 Johnson 6hp

Sorry I got so aggrevated about all the talk about the fuel pump. Let's all calm down a bit and look at this thing again. I just have one more question. You say you cleaned the carburetor. Did you pay attention to the high speed orfice in the bottom of the carb bowl? I only ask this because everybody seems to fail to realize that it's even in there. That orfice has to be absolutley shiny clean or it won't run. I'll shut up now.

 

[Gridiron]

Re: 1969 Johnson 6hp

Yes, I removed the plug. Put new washer on and unscrewed the orfice. Cleaned area where orfice was and cleaned orfice squeeky clean. I made sure when I rebuilt the carb that everything was clean and I followed my service book. I did not remove the leaf plate ***. to see if it is good.

 

[Good Ol Boy]

Re: 1969 Johnson 6hp

There is a vacuum line that tucks right underneath the spark plug wires, every motor ive seen of this year the hose is painted the same color as the shaft, that hose is notorious for cracking at the insert point on top and bottom which would cause your motor to start then stall out.

 

[jay_merrill]

Re: 1969 Johnson 6hp

This is a three year old thread. That said, the hose that your are talking about is not a vacuum line - its for lubrication. It would have no effect on starting.

One thing that does have an effect, is points adjustment. I have found the points motors to be very sensitive to proper adjustment. They must be adjusted to .020 exactly at the peak of the lobe on the crankshaft. Some people prefer to set them at .018, but once again, getting this adjustment at the peak of the lobe is crucial.



???