1969 Johnson 9.5 troubles(newbie)

[sherlockian]

Hello, I am new to boating. I just purchased an old 12' fiberglass boat with a Johnson 9.5 hp on it. The engine was not running when I purchased it. The owner said he thought the fuel pump was bad. I bought a fuel pump and carb kit. I rebuilt both and reinstalled them. I also replaced the water pump impeller and spark plugs. My problem is that I took the boat out and the engine would run excellent(idle to full throttle) for about 15 mins. Then the engine would slow down by itself and eventually quit. It would take about 20-30 minutes before I could restart it. Again it would run fine for about 15 mins, then the cycle would start again. I only did this three times to cover some long distances and used my trolling motor the rest of the time. I need some advice because this is the first outboard I have ever dealt with. I am thinking that the "electronics" are going out, possibly points, condensers, or coils. If anyone could give me some advice or help, I would appreciate it.<br />Thanks

 

[Paul Moir]

Re: 1969 Johnson 9.5 troubles(newbie)

Welcome to Iboats, sherlockian!<br /><br />Sounds like you're overheating it to me. Better R&R the water pump and at least have a look at the thermostat before it's blown.<br />Like any outboard, the water pump must be serviced every few seasons. If you don't know when it was last done, it's due.<br />It's neither difficult (usually) nor expensive.<br /><br />There's very little to the ignition system, and the two cylinders are totally independent of one another. So failure of both at the same time is rare in the extreme.

 

[RPJS]

Re: 1969 Johnson 9.5 troubles(newbie)

Have you got the tank vent open!

 

[sherlockian]

Re: 1969 Johnson 9.5 troubles(newbie)

RPJS, no the tank vent is not open(I am not that new, he-he, ha-ha). Paul, I replaced the water pump impeller before my original post, and it does not seem to have any problems. I am thinking about the thermostat now. The hole on the lower rear of the engine blows a little water when running, but after it heats up there is steam coming out and the engine is too hot to even touch. Can anyone tell me where the thermostat is on this engine.<br />Thanks

 

[sherlockian]

Re: 1969 Johnson 9.5 troubles(newbie)

Well, I found the thermostat and removed it. Boy, that was a bugger to get the cover off. I tested the thermostat in water and it operated just fine(opened up at around 180-190 degrees). Now I am at a loss as to what it could be. A friend suggested that my fuel/oil mixture could be wrong, but I mixed it 50 to 1. I need help.<br />Thanks

 

[tashasdaddy]

Re: 1969 Johnson 9.5 troubles(newbie)

replace the t'stat any way, 180-190 seems awfully hot. also sounds like it could be getting hot and the coils failing. have you tested spark when it was hot?

 

[walexa]

Re: 1969 Johnson 9.5 troubles(newbie)

Since you have ruled out the t-stat, I believe when you put the lower unit back on from replacing the impeller.......that you didn't get the water pickup tube back in place where it goes into the water pump outlet. Therefore, you are not not pumping water up into the engine. If it is in place, there is also a rubber grommet that seals that tube off that could be missing. Check it out and let us know.<br /><br />Waylan

 

[Paul Moir]

Re: 1969 Johnson 9.5 troubles(newbie)

Tstat should start opening at about 140. I think you've found your problem.