1973 Johnson 9.5 Floods out

[swedishpimple]

We just picked up a 1973 Johnson 9.5. It was running great, but now seems to flood itself out while running a slow speed.

Is this just something in the slow speed idle?? COuld it be crappy plugs?? They don't seem fouled but they don't look real clean either, which I thought made sense if it is flooding all the time.

[Valv]

I believe your model should have a know in front of motor to adjust idle richness. If it's missing look for a hole in the cowl, below pull handle or vicinity.

[swedishpimple]

Valv,

Yep...the knob is there for the slow speed idle richness/leaness. It does seem to be working too. SOmebody has been messing with it, including myself, so I am not sure what it should be set at for this alt. and temp.

A goofey thing with this motor is the location of the carb. It is towards the back of the motor with the intake open to the top. I am also wondering if we got a little water down in the carb.

[Valv]

Do you mean the front of the motor, near the transom right ?

Many models had no "airbox" on carb, it was just open to air but there should be no water intrusion anywhere.

The knob is made to adjust idle mix at idle or WOT, try to adjust it toward LEAN when idling.

[HUNTINGBAILEY]

COULD ALSO TRY THE FLOAT IN THE CARB MIGHT BE STICKING. THE CARBS ARE PRETTY SIMPLE.

[DinkADunk]

I would take a small fuel tank with 1 gal of fresh gas mixed with 1 can of seafoam and run it at or near WOT for awhile (10-15 min) to clean things up then switch to your normal fuel tank and adjust the richness.

[iffwalleyes]

Quote:

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I would take a small fuel tank with 1 gal of fresh gas mixed with 1 can of seafoam and run it at or near WOT for awhile (10-15 min) to clean things up then switch to your normal fuel tank and adjust the richness.

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Or better yet get a can of Evinrude/Johnson can of engine tune. Follow the instructions on the can. You spray about a 1/2 of the can into the carbs while running. Then you let it sit and soak for about 10 hours and run it again and watch the black crud come out of the motor. This stuff works really good. The idle richness make a noticable different when you adjust it. You should know where it needs to be just by how the motor response. If it doesn't then you should give everything a good cleaning up. My dad has one of these that is about a 69 model and it still to this day will start on the 3rd pull after long periods without use. I wish today motors where similar in this reguard.

[swedishpimple]

Part of the problem is keeping the motor runiing long enought to use any of the "tune-up" products. It runs the longest after I flood it, then disconnect the fuel line and pull and pull until it fires an runs, then it will run for about 30 seconds. (That is the procedure in the owners manual for a flooded motor)

Then it eventually runs out of fuel, if I add the tank it either floods out or is not actually getting the fuel.

[Valv]

It is then carb float problem. Try seafoam in gas, otherwise you will have to pull it, open bowl, and clean well. The bowl needle is sticking and letting gas in while full.

[VMS]

Hi everyone,

Maybe it is just me, but with the age of the motor, why not just do a carb rebuild? The kit and rebuild is cheap insurance, plus the cleaning of all the little ports of gunk, etc.

I would tend to agree with Valv that the float is the issue too... I would also consider replacing fuel lines from the male end up through the fuel pump and on to the main motor. If those hoses are the original, it may prevent future clogs in the carb due to a deteriorating fuel line.

Guess I am one of those who preaches preventative maintenance before issues occur...

steve

[swedishpimple]

Motor Update:

Last night I reconnected the gas line...squeezed the bulb, pulled about a dozen times to get it running (fired after 6 or so)..put the muffs on so I have water....gave her a shot of carb cleaner...that killed it....so I fired it up again...she took right off....I gave her another little shot and repeated this for about 10 minutes. Seems to be running like new.

I do plan on adding sea foam to all of my tanks,,,,,and telling everyone to keep their hands off the slow speed idle.

We got the motor from a mechanic at a dealer on brokerage..it looked clean and they claimed they went through everything. It may have been a combination of bad gas..bad luck...a sticky float...old fogging oil...little kids playing w/ knobs and operator error. Hopefully we will make it through the weekend.

[Surface Tension]

Carb cleaner sprayed into the carb isn't cleaning the carb. It has to pass through the carbs inlet to clean.

Your Low Speed adjustment knob is where you should start.

Normally if that has no effect then the carb is dirty or in your case bad inlet valve causing an improper gas/float level.

Back to the Low Speed adjustment. You'd adjust that while at low speed. If you can't keep it running at low speed then throttle up just enough to keep it running. Make a small adjustment and throttle down, if it gets better continue to richen or lean out the idle. Which way to turn? If your sure its flooding out then you lean the mixture. If its popping you need to richen the mixture.

If you have wet or dirty plugs then you should replace them first. Its rare that the engine should flood because of slow speed adjust. Well not to the point that you need to plug the gas line off and continually pull to get rid of that gas. If you have that much gas to flood the engine I'm suspecting a sticky inlet valve or one thats not seating correctly.

One more thing. Don't start the outboard even for a short time without the muffs on. Ever get a floor burn on bare knees? Thats how long it takes to burn the rubber impeller.