1969 Johnson 115 cuts off when engaged in forward

[dmhfab]

1969 Johnson 115 Hydro Electric Shift. Motor has not been run in 5 years. Replaced faulty power pack. Rebuilt all the carbs. New oem fuel pump. New distributor cap. New fuel lines. New spark plugs and wires. Motor will start and idle okay, a little rough, with the low speed jets set at the factory setting. When initially started up after all the above listed parts being installed, it would start in neutral and shift into reverse fine. If you tried to shift to forward it would shut off before even trying to shift. At that time found the primer bulb was bad. Installed a new primer bulb and hose assembly. Tried the motor once with the new primer bulb and hose from tank to engine and it would then start fine and shift into both forward and reverse. I do not know if that was unrelated and just by luck. I let it sit for about a month and then went to adjust the carbs and I am now having the same problem. Motor will idle(not the smoothest) and shift to reverse fine. However if you try to even move the control a 1/16" of an inch into forward it dies instantly. I tried disconnecting the two wires to the hydro electric shift, as that should force the engine to be in forward. Tried to start it that way, with the controls in neutral and it would run and turn the prop in forward until I let the key off the start position and instantly die with the key in the run position.

Any ideas? Thank you.

 

[racerone]

I am going to be blunt.------That is a lot of money / effort to save that model.----Sounds like there might be a wiring issue on the key switch.-----Any pictures of the motor and wires on the key switch ??

 

[F_R]

Runs with key in start position but dies when you let it off to run position. Pretty clear evidence you have a bad key switch. OR screwed up wiring errors. I don't know what to make of the other issues, such as cutting off when shifting.

 

[jimmbo]

Deleted

 

[dmhfab]

Here is the wiring diagram from the factory service manual. I do not see any feedback from the key as to what gear it is in. It starts and runs fine in neutral and will shift into reverse okay. If the two wires feeding the hydro electric shift are disconnected it should default into forward. However with those two wires disconnected it will only stay running when the key is in the start position, and cuts off instantly when the key is allowed to go back to the run position.

 

[dmhfab]

[No message]

 

[dmhfab]

Could it possibly be the safety switch for neutral on the engine? Or the gear selector switch in the controls? It really confuses me as it had this exact issue; Then I changed the fuel primer bulb and line assembly and it worked perfectly. Then let it sit for a month and had the same issue with it instantly cutting off whenever the the control lever is moved at all towards forward gear.

 

[dmhfab]

I am going to be blunt.------That is a lot of money / effort to save that model.----Sounds like there might be a wiring issue on the key switch.-----Any pictures of the motor and wires on the key switch ??

What pictures would you like on the motor? I posted the factory wiring diagram, but can take any pictures that may be helpful. Thank you.

 

[F_R]

See post #3. It's the key switch or there is a wiring error related to the starter solenoid.

 

[dmhfab]

See post #3. It's the key switch or there is a wiring error related to the starter solenoid.

May be a dumb question but what does that have to do with engaging forward gear? With the hydro electric solenoids the engine knows no difference between what gear it is in from what i understand. Ill be glad to replace the key switch but just trying to understand how that would effect only forward gear.

 

[dmhfab]

New key switch, same problem. Starts and idles fine in neutral, shifts into reverse fine, cuts off instantly in forward.

I am wondering if it something in the lower unit and a plunger is sticking or ball valve so when it is shifted into forward it is leaving another passage open putting it into forward and reverse at the same time killing the motor.

 

[spybot]

OK with my limited knowledge on this type of motor i would check the control box.
If it starts in neutral and fine in reverse but dies in forward, could the control arm be catching/chaffing a wire which cuts the motor ?? Maybe the kill switch wiring ???
Like i say i dont know this motor but if it was mine i would strip down the control box and take it from there

 

[dmhfab]

OK with my limited knowledge on this type of motor i would check the control box.
If it starts in neutral and fine in reverse but dies in forward, could the control arm be catching/chaffing a wire which cuts the motor ?? Maybe the kill switch wiring ???
Like i say i dont know this motor but if it was mine i would strip down the control box and take it from there

Checked that and did not see a problem. Started it up this weekend it went in forward fine again. Cut it off and back on and then had the same issue with it shutting off in forward. Motor sounded much rougher when it would not go into forward. Started checking other things. Checked for spark on all the plug wires. With the plugs out and cranking the motor over it, it showed spark on all 4 cylinders. Then put the plugs back in and started the boat and it was doing the same thing with shutting off in forward. I took a timing light with it running and found two cylinders are not getting spark with it running, although all 4 showed spark with it cranking with the plugs out. I am going to try and adjust the pickup gap on the timing base to a smaller clearance and see if that will help any. I believe now that the no spark in two cylinders while running is affecting it being able to go into forward. Just confusing it worked again one time and then back to the same problem. It only has one coil and a rotor and pickup on the timing base that closes a circuit to tell the powerpack to fire, so i think something is going on with the pickup sensor on the timing base.

 

[racerone]

Perhaps run at night and see if there is a " lightning show "-----The wee rubber boots on the distributor cap have been known to fail.----Spark will jump to the flywheel there.-----Clean distributor cap insides.----Clean the rotor.-----Perhaps there are issues with cracks in the distributor cap.-----Test it / find a shop that that can test it, as a new one is big $$$