end of the rope

jroberts24 · May 5, 2003

Hi guys, I have talked about this motor that I have multiple time on this forum, but I am now at the end of my rope. I purchased a QD-16 1955 Johnson 10hp. I probably has less than 5 hours on it. When I first got it, it cranked up and ran for about 15 min, then died all of a sudden. It sat up for a while and there was gunk in the carb. I could not find any outboard mechanic in my area that would touch it. So, I purchased a owners manual and a service manual and decided to work on it myself. I am no outboard mechanic by far, but I can do most minor stuff. I changed the water pump impeller first, because it sat up for awhile. Then I purchased a carb kit and installed it. I set every thing to service manual specifications. I put new plugs in it and gaped the points correctly. As of right now, I have great fire and fuel getting to the carb. My tank is staying pressurized good and it is hooked directly to the carb. The engine has good compression. It will crank and run smooth for about 5 sec., then will die. If I keep pulling on it, it will not crank again. If I let it sit for awhile, it will crank again and die. Also, if I continue to try and start it, gas will drip out of the intake of the carb with breather off. The spark plugs are damp with gas if not dry. Got fire, must be gas right? I really like this motor, i really don't want to turn it into a flower bed center piece. I have a lot of time invested in it. The problem with this motor, is either really simple (I'm over-looking it) or it is beyond my knowledge of 2 cycle engines. Any help would be much appreciated. Should I cut my losses now or continue investigate the problem. Thanks, jroberts

petryshyn · May 5, 2003

Re: end of the rope

One thing to check on that ol' girl is the ignition coils. The insulation likes to weather crack over the years which allows moisture into the high voltage windings. You could be losing spark after a few seconds....

jroberts24 · May 5, 2003

Re: end of the rope

Thanks schematic, I saw the weather cracks and repaired the insulation with a little fiberglass. It has great fire. I pull each plug out, still connected, and watched the fire for multiple pulls. Thanks, jroberts

wezie · May 5, 2003

Re: end of the rope

Just Guessing. The passages in the carb in small engines are very small and some are even difficult to see when filled with junk, and hard to clean. There may be one that you have not found. Carbs are magic you know. Just like electricity, airplanes and computers. Had a lawnmower that had one small passage that I found on the third try; had to dig the junk out of it and it was not as old as yours. Floats also give fits when they do not work smoothly and/or when the needles or seats are contaminated. If float is not new, test it to see if it floats. Look for the small passages and keep trying to get everything in the carb clean. Wish I could tell you just what to do?!

petryshyn · May 5, 2003

Re: end of the rope

wezie could be on track as well. Take some of you pre-mixed fuel and put it in a spray bottle. Try squirting small amount into the carb bore just as it starting to stall. If it keeps running, you know its a fuel starvation issue.........don't give up! She'll be sweet when you resolve this....

ob1jeeper · May 5, 2003

Re: end of the rope

from your comments about it won't crank again after you've pulled on it a bunch, it sounds like you're saying that it feels almost like it is "seized"... Did I get that right? If so... then you are probably running SO very rich that you're getting the cylinders to "hydraulic" against the mass of fluid in the crankcase... I'd double check the carb kit specs, to make sure the needle & seat are properly installed and closing off or "seated" when the carb bowl is full. The tank really doesn't need to be pressurized to feed enough fuel, there should be enough pressure head without it being pressurized... Try running it with the cap off (no pressure) to see what happens... Good Luck...

alcan · May 5, 2003

Re: end of the rope

Hi Jrobrets Not trying to be a wise guy here, but your problem is something very simple. I have been hung up trying to solve these madening problems only to be humbled by some stupid little thing I over looked. Relax,it happens. The first thing is to start over. Go over all systems like you just got the motor 15 min. ago. OK no amount of sealer,goo,fiberglass or what ever will not fix those coils. Once they are split replace them. Oh yea they will spark like crazy when your lookin. The tank has to have presure all the time if the motor is going to run longer than the fuel that is in the bowl. Use compressed air, squirt type carb cleaner and wear safety glasses when cleaning the carb. Try not to use wire and such unless absolutely necessary. Then very carefuly. Did you set the float level correctly? Did you install the main nozzle gasket? You said you have the tank hooked direct. Do you have the right hose hooked to the right location (air to air and fuel to fuel)? Did you remove the knobs on the needle valves for cleaning and adjusting? They have limits built into them,this is to help keep from being over adjusted while in use. While tuning remove knobs, this will help keep you from getting a false bottom (reading/setting). From your description I am leaning toward flooding (too much fuel). If float valve and float check out, then I suspect the main nozzle gasket. This assumes you set the needle valves according to the book. Don't worry we'll get to the bottom of this.

Boatist · May 5, 2003

Re: end of the rope

JRoberts I think your motor is flooding. Here is what I would do. Open gas can and let any pressure out. Hook up your fuel line and pump bulb one time. Disconnect the fuel line and try and start. If it starts turn your idle mix in a little for leaner fuel. If it continues to run adjust fuel mix slowly, turn a little and weight 5 sec to see if speed up or slows down. Adjust for best speed. If you have not run gas out of carb last time then try to start with out hooking up fuel line first then try above. If it does not start put fuel line back on and pump one more time and try again. Repeat until get it to start but do not leave fuel line connected. Here is my idea and my 15 hp has done same thing before. I think Float in carb not sutting off fuel so fuel pump is pumping fuel and overflowing the carb and engine sucks it up into lower end. Once it in the lower end take foever to clear out. My 15 did same thing, it would start run 20 sec to one minute and die. After that could crank on it and it would not restart. The way I found it was took carb off one day and took inside cleaned it and took air compressor to blow out everything. Took back out to the boat after about 1 hour and installed the carb. Did not hook up the fuel line and had plug out so gave it a couple of cranks. Put plugs in and hooked up wires but no fuel in carb and no fuel line. Pulled the crank one more time and to my supprise it started. Not omly did it start it ran for over 5 minutes with no fuel. This is when I realize that if flooded can have lots of fuel in lower end. Final fix was to get a new float one that actually floats in gas. One other way you could try is to leave gas line off and pull the plugs and with a squirt can squirt one or two squarts of fuel mix in each cylinder. Put plugs in and crank when it starts let run until speeds up and starts to die then squirt in carb air inlet with fuel mix. If it rums this way you know it is a fuel flooding problem. Be carful as fuel will burn anywhere you squirt it. If it is a flooding problem as I belive then Likely float that will not float in gas, float needle or seat not shuting off fuel, Float adjusted too high, or float haning up on bowl sides. Good luck and let us know what you find please.

Chinewalker · May 6, 2003

Re: end of the rope

REPLACE THE COILS! New ones are cheap and readily available. If you've got an "in" at your local NAPA you can get them for under $20.00 apiece. Retail is still less than $30.00. Replace the condensers while you're in there. Sparking in the open air is a whole lot different than sparking in the high resistance of compression... - Scott

jroberts24 · May 6, 2003

Re: end of the rope

Thanks guys, I am going to give these ideas a try. As I said, I really like this engine and don't want to let it go. I will post when I get it revived. Thanks for all the help. jroberts

Boatist · May 6, 2003

Re: end of the rope

JRoberts I would not just replace the coils. Just too easy to test for spark. Take a old plug and gap to 3/8 to 7/16 of an inch. Hook a battery charger clamp to plug base and ground to block. I made a little spark tester with two battery charger terminals and a short wire cost less than $1. You could also use one wire of jumper cable to groung old spark plug to block. Anyway move one of your spark plug wires to the plug with the wide gap and crank if jumps 3/8 of inch of this plug spark is not your problem. Then check the other wire. If it does not spark then check the point and condensor and then coils. Isolate the problem first then fix. Dont just throw money trying to fix parts that are not broke. Can end up with two problems and even harder to fix. If you have a timing light can also check timing but if it starts and runs for a while them timing should be ok.

Chinewalker · May 7, 2003

Re: end of the rope

Regardless as to whether there's a fuel problem or not - REPLACE THE COILS! Cracked coils WILL fail, and usually when you least can afford it - like the day you forget your paddles and there's a large cruiser bearing down on you! Cracked coils that have been recovered now have moisture trapped inside, moisture that can cause shorts, leakage, etc. Replace the coils and you'll know for sure what is NOT your problem. If they were rare and expensive, then I'd be all for making do, but they're CHEAP and READILY AVAILABLE! Replace them and let your grandkids worry about them... - Scott

alcan · May 7, 2003

Re: end of the rope

I agree with Chinewalker! Split coils are a for sure known problem and need to be replaced.

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