Johnson 200 intermitten stall

[Hydrostream dream]

Hello, I've recently purchased a 200 Johnson, 1995, and it will barely idle and die when put in gear, after a time, IF I can keep it running, I can accelerate ok, and top out fine. But after stopping for say 15 minutes, and restart engine, it barely idles, and will die if acceleration is attempted again (had to "baby" it all the way back to ramp). The smell of fuel becomes apparent. I checked compression and find 115-120 on all cylinders. The spark plugs look somewhat alike with the exception of cyl. #1&3 seem rich. Keep in mind that IF I can get it "past the hump" of getting in gear and slowly accelerate, this engine will perform well at high speeds. I know from my technician days (mid 80's) that these engines are notorious for idling problems, but not this bad. I'm thinking that a carb rebuild may be indicated, but usually (in my experiences anyway) a fuel shortage is symptom of dirty carbs, not excessive fuel. Any help is greatly appreciated. Thanks!

 

[tashasdaddy]

Re: Johnson 200 intermitten stall

have you checked spark on all cylinders, when it is doing this. a stuck open carb float will flood the motor, excessive fuel, making it hard to start, or idle. you have good compression, and if the spark is good, then you have a fuel problem.

 

[Dhadley]

Re: Johnson 200 intermitten stall

Remember the idle and mid range jets are air jets, not fuel jets. Also remember the starboard cylinders are fed by the port side carbs. That motor should idle just fine, they really aren't know to have a bad idle unless something is wrong.

 

[Hydrostream dream]

Re: Johnson 200 intermitten stall

Thanks guys for the super fast response. I haven't checked spark when this problem occurs as it will be very difficult without a test prop on the back of a 18 Hydrostream. I'm gonna head towards rebuild of carbs as suggested. I had forgotten about the fact of air jets instead of fuel, along with most of what I knew back in the days of tuning these engines. One additional thought, I found the tube at the top of the linkage system that apparantly adjust the timing had the set screw loose and the adjustment screw on the end (appeared) to have backed out. Is there a measurement for this screw, or is it adjusted by timing light. Again, I really appreciate your help, I can only hope to assist someone in return.

 

[tashasdaddy]

Re: Johnson 200 intermitten stall

it is adjusted with the link n sinc procedure, could be part of your problem.

 

[Dhadley]

Re: Johnson 200 intermitten stall

That tube is the idle adjustment. It moves the timer base without moving the throttle linkage. If the locknut is loose and the tube has unscrewed that should allow the initial timing to advance which could result in a high idle. Just set the timing so the motor idles at 750 or so in gear. That adjustment may have to be set a bit higher than normal on that boat. The weight of that motor makes it sit pretty low in the water so there's quite a bit of backpressure until you get moving.

Cool ride. With the right prop that should be a blast. Is it the V-king?

 

[Dhadley]

Re: Johnson 200 intermitten stall

If the idle won't come up by unscrewing that tube, look under the flywheel on the other (port) side. There may be a bracket with a screw in it. You can turn that screw in to advance the initial timing. Don't move the screw on the starboard side with the rubber end. That's the stop for the total timing.

 

[Hydrostream dream]

Re: Johnson 200 intermitten stall

Thanks again for all the help. I spent a couple of hours last evening checking this thing out.....and found that these 200's have changed some since I used to turn wrenches on 'em back in the mid-late 80's, particularly in the carb area. When the carb is removed, there is a needle valve in the butterfly area. Is this needle for an air adjustment...I assume??? I'm thinking I may can lean out cylinders #1 & 3 just a bit to help with the rich condition. I checked all 6 of these needles and all are right at 4 turns out from bottom, but I was hesitant to make any adjustment until I determine what they do and affect. I checked/cleaned all idle jets and checked floats/inlet needles, all appeared OK. I'm thinking you may be onto something as for the backpressure. This thing does indeed set very low in the water. I advanced the initial timing just a bit, but I will check the port side this eve for an additional adjustment. Oh, by the way, its not a V-king, its a Valero, in near pristine condition....runs great on top end, mid 80's, IF I can get it past the stall. THANKS AGAIN!!!!!!!!

 

[Dhadley]

Re: Johnson 200 intermitten stall

Ah, a Velero YT. Just sold mine to a guy in Norway. Once you get it dialed in you'll get more than mid 80's. My Vegas XT ran 88 with a stock 200 looper.

Yes, those needles are for idle air agjustments. Put them where ever they need to be for a good idle. Your adjustments may be a bit off from the book because of the backpressure. I've always prefered a hydraulic plate and one advantage is that at idle I can raise the motor up to get rid of some backpressure.

You'll have a blast, no doubt.