1969 6hp Johnson

G

Gridiron

Cadet
Joined
May 22, 2007
Messages
15
Well here I am again. This old motor just doesn't want to run. This is what I have done so far.

Rebuilt carb.
checked and cleaned the fuel filter.
Replaced head gasket (water getting inside bottom cylinder)
Replaced thermostat
new plugs


Before I replace the head gasket it would start for about two seconds and die. The lower spark plug was wet with water so I replace the gasket. The old gasket had a hole. I put the new gasket on and now it will not fire. I took the plugs out and pulled the starter cord. Had one hand over the two plug holes and no gas or gas smell was on my hand. I did put a inline fuel filter on the hose in between the tank and the primer bulb. Could this be my problem? Also when I rebuilt the carb I did not the leaf valves. Could they be fouled up?
 
F

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: 1969 6hp Johnson

OK, so why did the head gasket blow? Was it overheated? What are your compression readings? That water in there could have caused major damage. Leaf valves problems are extremely rare anymore, unless something got in there and fouled them up..like a dirt-dauber nest.

You need to begin with the basics. Compression, fuel, spark. You have already been into the carb, so assume it is ok and check the rest. By the way, on a two-stroke, compression means on BOTH sides of the pistons. Combustion chamber and crankcase. It's only a few pounds in the crankcase, but still has to be there. Scored pistons will kill that (back to the overheating question).
 
G

Gridiron

Cadet
Joined
May 22, 2007
Messages
15
Re: 1969 6hp Johnson

This was my grandfathers motor. I don't think he did much to it. He has been dead for 11 years and this motor was sitting in the old shop collecting racoon poop. Before he died it was running. He went fishing almost every day in Florida. I don't think it is getting gas. I think
 
JB

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: 1969 6hp Johnson

Go to the Engine FAQs, Gridiron.

Use a systematic troubleshooting procedure.

Let us know what you find.
 
G

Gridiron

Cadet
Joined
May 22, 2007
Messages
15
Re: 1969 6hp Johnson

I noticed the oild return hose was cracked and had a small hole. Can this keep the motor fram starting? Also when I rebuilt the carb. my original service manual says to make sure the float is level with the carb. casting. the new float sits up a little. I just can't figure out why it is not getting gas into the cylinders.
 
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