Thread: 1983 115 hp Johnson

This motor has been completely rebuilt by a professional shop. Super clean motor. The only trouble I'm having with it is it's flooding. When it's floods you can forget it it's not starting again until the next day. It floods while running at a idle. It will die while idling and it won't start again. I've put new plugs in it and took the carbs apart and cleaned them and I still have the problem. The carbs where the cleanest I've ever seen when I took them apart to clean them. I guess I'm going to try to rebuild them and put new floats and needles in them even though they look new. I've got to get this problem resolved because I've got to fish lol.

When you take the carbs apart, take the floats some place real quiet and shake them to see if they have any fuel in them. Some of the originals were prone to leak and get enough in them to cause them to stay open. And if you happen to have access to a Gram scale weighing them would be even better.

I would suggest that you replace the primer solenoid and see if the flooding issue is still there. If the plate is cracked it maybe leaking fuel into the carb throats which would cause a flooding condition.

That motor should have a tell-tale line on it. It is located on the right side towards the rear under the lower cowling. Looking at it from behind the motor.

http://www.marineengine.com/parts/jo...+Cover-johnson

Part #24

http://www.marineengine.com/parts/jo...p%3B+Crankcase

Parts # 22 And 50

If they are not there someone may have plugged the hole in the head
If the hose is there try sticking a stiff wire through the nozzle under the cowling to clean it out. Insects commonly build nests in there and plug them up.

That tell tale stream of water is a visual indicator of a working water pump and may save you from burning up your motor if checked every time you start it.

I called the shop today that rebuilt the engine before I got it. They said it sounded like a cracked or stretched diaphragm in the fuel pump. Bought a rebuild kit for the fuel pump and a rebuild kit for the primer solenoid. Rebuilt both and.......... Same problem!! I'm beating my head against the wall!!

This is probably a silly thing to check. But have your run it with the breather box off and made sure the choke is completely open?? If there is a linkage binding or a butterfly sticking it would could choke out idling, but still run up the lake...although very richly. May be why it will not start back up after it dies. Just a thought.

Are you positive it is flooding and not loosing prime?

I do not remember, but on the float needle...does it seat in an oring...or is it rubber tipped? I know you said you rebuilt them, and I'm not doubting you, but you might check and make sure the needle is seating completely...or that there isn't a small crease, scratch, etc on it that can allow fuel by. Make sure the float is set just below parallel when seated so you get a good seal. That isn't by the book...just how I do it. lol

Can you trace it to a plug/cylinder that is flooding when it dies or are they all wet? With two carbs you have different flows feeding each cylinder. You should be able to narrow it down to a cylinder or at least a pair. I would doubt the problem is in both carbs. Let it die then check all four. Maybe you will find a really wet one or two and be able to narrow it down a bit.

Not doubting your work...just some thoughts.

Thanks a lot for your help. I appreciate any ideas from anyone.

I didn't rebuild the carbs I just took them apart and cleaned them. They didn't look like they needed it. Cleanest carbs I've ever seen!!

I think I may have resolved the problem. I haven't got to run it enough yet to be sure. I think it's the primer solenoid flooding the motor. All four plugs are wet so I don't think it's a card issue. I unhooked the primer solenoid last night and it cranked right up and ran better than it has since I got it at a idle. Hopefully I'll get home today in time to test it further. I think the primer solenoid was pushing to much gas through it.

While you are working on the primer solenoid check the voltage on the control wire while using the choke switch to make sure it is disconnecting completely
The choke switch may be staying on or intermittently applying voltage. Should be "0" normally when running and 12 volts only when using the choke.
If showing some voltage you may have a bad switch.
If the voltage is OK I would suggest replacing the primer solenoid.
Sounds like you might be on the right track.
Good Luck