1984 Johnson 15 HP

[gizzard]

OK Here it goes.

I'm crusin down the lake full throttle and she cut out. I can save it some times by choking it other times when I choke it it just continues to die. It never seems to happen until after the motor warms up. After it dies I'm able to start it right back up and take off. Then once I reach full throttle it does it again. Some times however it doesn't mess up it just cruses along like nothings wrong.

Here is what I have done trying to fix the problem.

1. Installed a fuel pump. (made no difference)
2. Installed the rebuild kit for my carb (made no difference)
2. Checked the gas (made no difference)

Things I have noticed
1. The primer ball stays rock hard.
2. It seems less likely to mess up if I do not go FULL full throttle
2. It only seems to do it once its heated up.

Please any help would be so appreciated.

 

[gizzard]

Re: 1984 Johnson 15 HP

Ttt

 

[steelespike]

Re: 1984 Johnson 15 HP

Kill switch? maybe an air leak in the fuel line or connector.
In operation the primer bulb would normally not be rock hard.
only become hard if carb is full and float valve is closed.As soon as the carb calls for fuel the bulb would not be hard as the pump draws fuel through it.
With the motor off bulb may seem hard if float valve is closed. If bulb is allways hard a check valve may be sticking.Is the arrow pointing toward the motor?

 

[mikesea]

Re: 1984 Johnson 15 HP

Sometimes it can be as simple as a bad hose connector.I second the kill switch idea.It dont hurt to disconnect to test.they are intermittent often and sometimes just leak a small bit of ground which throws monkey wrench into the trouble shooting

 

[gizzard]

Re: 1984 Johnson 15 HP

Kill switch? maybe an air leak in the fuel line or connector.
In operation the primer bulb would normally not be rock hard.
only become hard if carb is full and float valve is closed.As soon as the carb calls for fuel the bulb would not be hard as the pump draws fuel through it.
With the motor off bulb may seem hard if float valve is closed. If bulb is allways hard a check valve may be sticking.Is the arrow pointing toward the motor?

yes the arrow is pointing the correct direction.

the check valve is the valve the rubber on the end of it? I replaced that and clean it all when I installed the new carb kit.

 

[gizzard]

Re: 1984 Johnson 15 HP

Sometimes it can be as simple as a bad hose connector.I second the kill switch idea.It dont hurt to disconnect to test.they are intermittent often and sometimes just leak a small bit of ground which throws monkey wrench into the trouble shooting

Air leak in the fuel line makes perfect sense! I'll buy new connectors and such. This would also make sense since when I choke it some times it will start back up. (the choke increases fuel demand) right?

 

[gizzard]

Re: 1984 Johnson 15 HP

Is there a maxim length for the fuel hose? From my tank to motor i'd say its 4 - 4 1/2 feet. maybe my fuel pump can't keep up drawing from the tank threw so much fuel line?

 

[tashasdaddy]

Re: 1984 Johnson 15 HP

average is 6 ft now.

 

[iwombat]

Re: 1984 Johnson 15 HP

length of the hose doesn't matter, only the height of the tank in comparison to the fuel pump. You're probably just fine.

 

[gizzard]

Re: 1984 Johnson 15 HP

OK

I have serveral hours in trying to fix this thing.
1 fuel pump + Shipping
1 carb kit + Shipping

Should I buy a new tank and hose with fittings as a last resort or go ahead and take my motor to Stranges boat shop?

 

[Whoopbass]

Re: 1984 Johnson 15 HP

You don't need to buy a bunch of stuff to test the fuel line or tank.
All that you need to run your outboard is a fuel fitting for the outboard (you could bypass this as well). Fuel line from fuel fitting to the bulb and then a fuel line to whatever you want to put the gas in. You can run the fuel line into a 2 liter bottle with gas and it would function fine.

 

[gizzard]

Re: 1984 Johnson 15 HP

You don't need to buy a bunch of stuff to test the fuel line or tank.
All that you need to run your outboard is a fuel fitting for the outboard (you could bypass this as well). Fuel line from fuel fitting to the bulb and then a fuel line to whatever you want to put the gas in. You can run the fuel line into a 2 liter bottle with gas and it would function fine.

I can't test it this way running down the middle of the lake. I'm about to throw this motor out the window!

I'm just gonna take it to the boat shop for repair. I can't figure it out. It has gotten the best of me!

 

[CATransplant]

Re: 1984 Johnson 15 HP

You could do that. Odds are, though, they'll have a lot of trouble figuring out what this intermittent deal is. If that's the case, it'll mean multiple trips to the shop, and your outboard still may not run right.

When did you change the water pump impeller last? Overheating can cause running problems, too.

What kind of tank do you have? A plastic one, or a genuine OMC tank?

If you have a nice flow of water, I'd run on down to WallyMart or somewhere else, and buy a nice new plastic tank and new hose, then try that out. It's good to have a spare, anyhow.

That would be a lot cheaper as a test than paying a shop to try to figure out an intermittent problem, I guarantee.

Also, if the engine "cuts out," meaning that it suddenly stops running, suspect ignition problems, not fuel problems. If by "cuts out" you mean it slows down and runs poorly, then eventually dies, then it still could be ignition, but you can add fuel, carb, and overheating to the list.

 

[gizzard]

Re: 1984 Johnson 15 HP

I'm about 99 percent sure its either the tank connection or the hose. I borrowed my neighbors tank and hose and it worked fine.

Thanks for everyones response.

 

[mikesea]

Re: 1984 Johnson 15 HP

Thats alot easier then taking the motor off the boat,pulling your back out as you throw it out the window(I would have just thrown it in the lake,easier that carrying it indoors to through out a window,besides you may need a new window too) Gotta have a laugh now and then.I recall throwing my chainsaw into the canal once.Made my life alot easier.Bought a stihl,and its still going.
One last serious question.I know you rebuilt the carb.Did you do a good cleaning.If its running ok now,I guess you found the problem.Happy Boating.