Johnson 2 stroke outboard not working

hit1987 · #1 08-07-2014, 07:04 PM

My friend bought a boat coming with 70hp Johnson 2 stroke outboard, 1976 year engine. The issue is that we can start the engine the first time after we let it sit for a few days. After we stop it , then we can not start it any more.
After we let it sit for another few days, then we start it again only for the first start. Then no matter how hard we try, it will not start.
Summer is here but we just can not get the engine to work.
Appreciate if anyone can drop a clue.

Cheers

Lund rebel · #2 08-07-2014, 08:17 PM

I was just working on a newer 1996 50 hp johnson outboard, was difficulty to start found a cracked standpipe in the fuel tank.

You sound as if you might have a fuel issue as well. How does it run when it does start, what have you checked so far ?

Have you gotten fresh fuel, checked plugs?

hit1987 · #3 08-07-2014, 11:07 PM

Thanks for your reply. When it starts and seems running fine. I do not know much engine. Will check cracked pipe or plug.

Cheers

harrydude · #4 08-07-2014, 11:16 PM

Quote:

Originally Posted by hit1987

Thanks for your reply. When it starts and seems running fine. I do not know much engine. Will check cracked pipe or plug.

Cheers

Were u located

Bushleague · #5 08-08-2014, 12:28 AM

Quote:

Originally Posted by Lund rebel

I was just working on a newer 1996 50 hp johnson outboard, was difficulty to start found a cracked standpipe in the fuel tank.

You sound as if you might have a fuel issue as well. How does it run when it does start, what have you checked so far ?

Have you gotten fresh fuel, checked plugs?

Yep, I fought with that this season too. This guy's symptoms don't have me completely sold on this being the problem but checking your fuel line for air leaks is always a good first step.

I've seen bad plugs do weird things once they get hot or the compression goes up as everything gets warm, that might be worth a try.

Kim473 · #6 08-08-2014, 05:05 AM

Vent on gas tank not opened, kink in the fuel line, maybe it needs the fuel filter changed if its been sitting for a long time it could be gumed up. Just a few of the simpler items to check first. I would put some wonder liquid in the fuel and see if that helps, called ( Seafoam ) Can get it at Canadian tire and other such places.

lannie · #7 08-08-2014, 07:02 AM

How long do you let it run for when you start it? The choke is not staying on is it? If that is not it maybe it starts to suck air between engine and Carb after it warms up? To test this spray break clean(or some other flammable aerosol) around every connecting piece between carb and engine. If rpm's increase while spraying that is where it is leaking. When you try to restart it is it starving for fuel or getting too much?

ksmitty · #8 08-08-2014, 08:32 AM

Had a similar problem on a 1980 johnson 90. After we took it for a run it wouldn't start until engine cooled down. I replaced the ignition coils and plugs and it was like a new engine

hit1987 · #9 08-08-2014, 01:22 PM

Quote:

Originally Posted by harrydude

Were u located

Thanks for your reply. I am living in Calgary.

Cheers

hit1987 · #10 08-08-2014, 01:24 PM

Quote:

Originally Posted by Kim473

Vent on gas tank not opened, kink in the fuel line, maybe it needs the fuel filter changed if its been sitting for a long time it could be gumed up. Just a few of the simpler items to check first. I would put some wonder liquid in the fuel and see if that helps, called ( Seafoam ) Can get it at Canadian tire and other such places.

Thanks for your help. tank vent is opened. do you know where the fuel filter located.

Cheers

hit1987 · #11 08-08-2014, 01:25 PM

Quote:

Originally Posted by lannie

How long do you let it run for when you start it? The choke is not staying on is it? If that is not it maybe it starts to suck air between engine and Carb after it warms up? To test this spray break clean(or some other flammable aerosol) around every connecting piece between carb and engine. If rpm's increase while spraying that is where it is leaking. When you try to restart it is it starving for fuel or getting too much?

Thanks for your reply. When restart it is starving for fuel.

Cheers

Peter

hit1987 · #12 08-08-2014, 01:26 PM

Thanks al for your time and help. I may all possibility and hope can fix it.

Cheers

Peter

dodgeboy1979 · #13 08-08-2014, 02:16 PM

i had the same motor. Things to look for that i found was check the primer bulb when the engine is running, mine would suck itself flat and stall out. The fuel filter and pump is on the port side of the motor. Unscrew the front off the housing and check to see if the filter is plugged up. Check all the linkages to the carbs to make sure they are all opening up at the same time. Check all your fuel fittings (ie tank and motor clips) to make sure they are not sucking air. trace all the fuel lines in the motor and make sure there are no kinks.

YeeHaw · #14 08-08-2014, 08:36 PM

The first things I would do is check the primer bulb, if its solid while running, check the plugs and see what they say. If they are carboned excessively, clean or replace them, and while they are out check for a crisp blue spark. Not to sound like a troll, but it is hard to do troubleshoot an engine with the description you have given. If you are in Edmonton, I might be able to take a look for you, as it is easyer to show you, than to try to tell you how to do it.