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New User has question about Johnson 10HP outboard.

R

rob1970

New member
O.K. Long story short. Bought a john boat and got a Johnson 10 HP out board with it. Free is for me and worst case, I have a 75 lbs. paper weight.I believe the motor is a 1963 QD-24. I put it in a barrel and after about 15,000 pulls, it starts. After it warms up, it idles fairly smooth and shifts gears w/ no problem. After about 10 mins. or so, I notice a film of grey oil floating in the barrel. I shut it down and put the motor in a stand and there is oil oozing out a weep hole on the bottom of what I believe is the cavitation plate. My question is what is the weep hole for and why is there oil coming out of it. Also, what is the correct gas/oil ratio, because this thing smokes pretty bad; the neighbors LOVE IT!
 
That sludge is normal for that motor !-----------Many times folks remove the thermostat for some reason, so check and see if it is there.--------Check the spark , it must jump a gap of 1/4" on both. If it does not then the magneto needs work.------Check lower unit for water after it sits for a few days.--Water in the lower unit is a killer on that motor.--------------Those 10 HP motors are sought after as they are elegantly simple to run and maintain.
 
QD-24 = 1963 10hp Johnson. Mixture is 24/1 (1qt 50/1 oil to 6gal gas), 87 octane gas is fine. Spark plugs = Champion J4C or J6C gapped at .030. Points set to .020. Gearcase lube is Hi Vis.

First, check for proper compression, then with the spark plugs removed, check for proper spark which should jump a 1/4" gap on that model with a strong blue lightning like flame... a real SNAP!

If the above is okay, the usual hard starting problem is a fouled carburetor. Remove, clean, and rebuild it with a complete carburetor repair kit.

The small hole at the cavitation plate is simply a water drain hole. Check the gearcase lube. DO NOT remove the philips screw from the skeg as that is a long shoulder bolt which is a pivot rod for the internal shift lever. If the gearcase lube is a milky substance, that is oil mixed with water and the leakage area will require correcting.

(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)
Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.
Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.
Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

(Checking Gearcase For Leaks)
(J.Reeves)

Remove the large slotted drain/fill screw from the bottom of the gearcase and also the identical looking screw that will be located up near the cavitation plate in order to drain the gearlube.
After all of the lubricant has drained, install one of the slotted screws, whichever your preference might be.

Apply 7 to 12 pounds of air pressure to the open screw hole. Use a piece of rubber fuel line or something to create a tight air hose fit if you do not have a proper fitting.
If a leak exists, that pressure should allow you to locate the leak by sound and/or sight.
 
racerone, kimcrwbr1, and joereeves,
Thanks for the info; I'll check it out sometime this week and let you know what I find. It might of been hard starting because it sat for awhile. Also, how hard is it to rebuild the recoil start? It was making a funny noise when the rope retracted. Thanks again.
 
Never heard of " rebuilding " a recoil starter on that model.---------------It just may need a bit of oil.----------------Do not lubricate the wee friction spring on it.
 
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