Merc guy looking for advice on Johnson

[ryanjames170]

I recently picked up a 1963 Johnson QD 24M and i am looking for some advice on both parts and what i need to do to get this old thing going.. also being that it has a fuel pump ( I know this a dumb question) but can i make a pig tale to run this thing off the same tank that i run my merc’s from? reason i ask is because i want to just keep one tank (easier for me to deal with right now)

im pretty familiar with getting old merc’s going but honestly i have never touched a johnson before and i really dont know much about that outside of getting parts is alot easier

[david-bartlett]

Ryan,

Welcome. Parts for the Johnson are plentiful and less expensive in general than the Merc stuff. You can make a pigtail and use your current tank for simplicity.

Be more specific about what you want help with on the QD and you will get lots of help here. Enjoy.

[ryanjames170]

basically i would be wanting to know what are common things that one should be looking at on this engine i know pump impellers and lower unit stuff is a must but are there any sort of issues that this engine might have that are common place to it.

i should also mention that i dont know alot about carbs on johnsons most of my experience has been with tillotson AJ series

[Anonymous]

Your 1963 has a number of improvements that earlier models lack:
Sturdier rods, wrist pins, gears, and the drive shaft is splined into the pinion gear.
In 1958 OMC switched to a smaller gearcase (one originally used on 5.5 and 7.5hp models, from one originally used on 15 and 18hp models) and some of those fixes are due to that change!

The carbs and magnetos on OMC twins of all sizes are very similar from the early 50’s thru the early 70’s, and parts are easily available. Basic maintenance doesn’t generally require any special tools.

Here are two pages with articles on working on them:
http://www.omc-boats.org/maxw.html
http://www.leeroysramblings.com/Outboar … icles.html

[lindy46]

Look for wear on the driveshaft and the bushing in the gearcase where the driveshaft meets the pinion gear. They are weak spots, and can show significant wear, especially if water has gotten into the gearcase. I had to find a replacement for the upper section of the gearcase and a "new" driveshaft for mine as both parts were scored badly. The driveshafts are getting particularly hard to find.

[outbdnut2]

If it still has original magneto coils, they will be bad, and visually look bad with dried up, cracked and flaking insulation.
Dave

[fleetwin]

Like others have said, the smaller gearcase is the weak link on this otherwise bullet proof engine…Decent driveshafts are getting tough to find as well.
If it were me, the first thing I would do is drain the gear lube and inspect. If the gear lube is milky/watery, I would pull the gearcase. Once the water pump is removed, the driveshaft should just pull out, it is splined into the pinion gear (unless someone has replaced it with an older style keyed driveshaft/pinion set up. Once the driveshaft is out, have a look at the lower area just about the pinion where it rides on the bronze bushing in the gear housing. Most of these driveshafts will show some minor wear in this area, but you are in trouble if gouging/wear is excessive.
Needless to say, you will want to check compression, it won’t have too much, about 80-90PSI is all. Everything else is standard service stuff for these engines, ignition, fuel system….Unless it is a salt water engine…
Once rejuvenated, you will really enjoy this 10hp….

[Author]

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