200 Johnson GT Idle problem

[joepauljig]

Hello,

I've got a 1990 200 HP Johnson GT that I can't figure out. Starting last year it developed this idle problem. When I start the motor, it will run a few seconds at idle and then die. It sounds as though it's loading up on fuel and then dies. I'm no mechanic so I'm not for sure if that's what it is doing or not. It doesn't "cough" and "spit" as some have described. It just dies after a few seconds. I can start it and then immediately push on the throttle and sometimes overcome the stall and then once I get it on plane, it runs fine. Then we start the process all over again when I'm ready to start it up again. It just won't idle. I had the carbuerators cleaned and adjusted about 2 years ago and I have used the boat heavily during the spring, summer, and fall months.

I've read through the forums and not sure where to start. I don't know if adjusting the timing knob will help or if there is something else I should start with.

Any help or suggestions would be greatly appreciated.

 

[jtcarter]

Re: 200 Johnson GT Idle problem

Top secret files at the top of the forum.
Have you changed your fuel filter?
Have you tried pumping the bulb while its trying to die on you?
Do you have a manual? If so check the lync and sync
If you left fuel in it over the winter did you stabilize the fuel with a treatment?

As you can see you need to start with the basics and do a process of elimination.

 

[joepauljig]

Re: 200 Johnson GT Idle problem

thanks for the suggestions jtcarter. The fuel filter hasn't been changed to my knowledge. I'll have to double check. I haven't tried pumping the bulb while it's dying. funny thing is that it idles fine on the hose. I don't have the manual but it looks like I may have to get one to try the lync and sync method.

so I'm guessing I shouldn't start messing with the idle adjustment just yet?

thanks again for your help.

 

[jonesg]

Re: 200 Johnson GT Idle problem

www.outboardbooks.com

 

[dajohnson53]

Re: 200 Johnson GT Idle problem

thanks for the suggestions jtcarter. The fuel filter hasn't been changed to my knowledge. I'll have to double check. I haven't tried pumping the bulb while it's dying. funny thing is that it idles fine on the hose. I don't have the manual but it looks like I may have to get one to try the lync and sync method.

so I'm guessing I shouldn't start messing with the idle adjustment just yet?

thanks again for your help.

Just a couple of things, but don't in any way think it's where you should end....

When I hear that it's idling fine on the hose but not in the water, I think of the idle not being high enough. When on the hose and not submerged in the water, there is no "back pressure" against the exhaust which flows out of the prop. Therefore, the idle needs to be set a little high on the hose and it will be lower/normal when in the water.

Also, change that fuel filter. It's cheap, easy and quick.

There might be other fuel issues too - a start for any further troubleshooting is to check the fuel system from the tank pickups, through all the hoses and connections up to the fuel pump and carbs.

I won't get into the fuel pump and carbs because I know little about this. But the couple of little things I mentioned above have solved a lot of problems for me in the past.

Oh, that and spark plugs and spark plug wires - another little thing that a rank amateur like me can check/replace, is often a cause of problems, and is always part of a more comprehensive system-wide check.