1991 200 Johnson - Warm Starting Issue

[AATA]

First, thanks for all the great info on this site. I bought a used ski boat with a 1991 200hp Johnson and have a couple questions.

Overall the boat runs good, but after the engine is warmed up and I turn it off for a minute or so (like to wait for a skier) it won't start without the fast idle all the way up and it still takes 2-3 tries. Once it starts, it idles smooth and runs great. I took it to the local shop and they said they would adjust the idle up, but it didn't change a thing. Not even sure they did anything, but that's another story.

My question is....is this normal for this year/make model or should it be able to sit for a few minutes and still start without fast idle? Is there maybe a check valve that is letting fuel leave the carb?

Here's a few things I checked. The compression is 95-100 on all cylinders. Has brand new plugs and good fuel.

Any ideas would be appreciated.


Thank you!

 

[AATA]

Re: 1991 200 Johnson - Warm Starting Issue

Anybody? I ran a search and couldn't find anything. Your input would be helpful. Thanks!

 

[clarky711]

Re: 1991 200 Johnson - Warm Starting Issue

I'll give you a free bump, as my 1987 90HP Johnson is doing the exact same thing...

Anyone have any ideas?

Thanks.

Mike

 

[fortyfreak9]

Re: 1991 200 Johnson - Warm Starting Issue

I have an 89' Johnson and I don't see how it would be normal for you to go to those measures to start it. I can't tell you what it is exactly. I am not sure how changing the idle would make it start different... my 2 pennies.

 

[AATA]

Re: 1991 200 Johnson - Warm Starting Issue

I would still like to hear what one of the experts on the forum think, but I was told by a local mech. that with the older carb engines the newer fuel evaporates fast and when you sit for a minute or so, there's not enough fuel to start the engine. Not sure if I believe this is the only reason or a reason at all?

Any input would be appreciated. Thanks!

 

[offshoreisle]

Re: 1991 200 Johnson - Warm Starting Issue

I'm going thru the same exact thing with my 2000 Johnson 200. I've had the motor since new, it just started doing this. I've got a post going, you might want to check it out and see what I've done so far.

One thing I plan to test tomorrow is the "Fast Start" cycle in the powerpack. Supposedly it advances the timing when you first crank the engine which helps with starting. This could be a big problem with warm engine and rich mixtures. When you advance the throttle you manually advance the timing, so I'm hoping this is it.

I'm not sure the '91 model had this but you might want to check it out. I'll let you know if I get mine fixed and what I find. (Maybe a Yamaha!)

Paul

 

[offshoreisle]

Re: 1991 200 Johnson - Warm Starting Issue

Just a follow up. The fast start circuit seems to be working when I check it with a timing light. The primer also tested ok, no leaks etc...

Believe it or not I repaced the starter for the hell of it. I felt the engine turned a little slow when warm. It seems to be a lot better. I ran the boat once so far and it started great after a long run. Hope this helps

 

[jonesg]

Re: 1991 200 Johnson - Warm Starting Issue

I would still like to hear what one of the experts on the forum think, but I was told by a local mech. that with the older carb engines the newer fuel evaporates fast and when you sit for a minute or so, there's not enough fuel to start the engine. Not sure if I believe this is the only reason or a reason at all?

Any input would be appreciated. Thanks!

Maybe he meant vapor lock,
I'd start by getting a factory service manual.
www.outboardbooks.com

 

[daselbee]

Re: 1991 200 Johnson - Warm Starting Issue

I would still like to hear what one of the experts on the forum think, but I was told by a local mech. that with the older carb engines the newer fuel evaporates fast and when you sit for a minute or so, there's not enough fuel to start the engine. Not sure if I believe this is the only reason or a reason at all?

Any input would be appreciated. Thanks!

That's very easily checked. If you have no fuel in the bowls after sitting a few minutes, you can fill them back up by pumping the primer bulb. If it only pumps once or at most twice, the bowls were still full. If you have to pump and pump until the bulb gets firm, the bowls were likely empty.
THIS IS ASSUMING THAT YOU DO NOT HAVE ANY LEAKING NEEDLES, OR CRACKED PRIMER SOLENOID FITTINGS, ETC.
As a test, pump the bulb til firm and see if you still have "hard starting when warm" issues.
If it persists, I would look at a flooding/carb overflow/too rich problem. Look at the plugs also. Are they wet wet wet?

Quickstart is working if, when you start it, and it idles about 1100, then after a few seconds, maybe 10 secs, it idles down to normal, maybe 800 in neutral in the water. The fast idle lever should not be up when assessing the operation of Quickstart.