1958 Johnson 18 HP starting today

[BDbill]

I finally tried out the 1958 Johnson today, here's what happened:
1. It didn't want to start unless I had it going fast in neutral. I'd get it started then turn it down. I tried a long time starting it where it was marked on the tiller before I tried it in fast.
2. It sounded great, but when I tried tuning it, it wanted to kill everytime I tried adjusting the fast and slow needles. The engine wanted to run at a fast idle.
3. I noticed a white foam coming from a weep hole below where the lower unit separates to change the water pump. When I changed the water pump yesterday, I did notice some oil by where the exhaust leaves the motor, where the shift shaft attaches to the lower unit. I'm guessing it was from that oil because when I drained the lower unit oil, it looked great, no signs of water. I've included a few pics of this, the one pic the foam is hard to see, but it's on the one side.
What should I do now? A carb cleaning? I'd appreciate any help, I'm a true novice when it comes to outboards and engines in general. Thank you for looking.

 

[jbjennings]

Re: 1958 Johnson 18 HP starting today

Carb. cleaning for sure.
I wouldn't run it in that darned bucket. Get yourself a decent trashcan. If you don't keep the water level a good ways above the water pump housing it won't pick up water and overheat your motor.
The white foam is unburnt fuel mixed with water and they all do it. run it in a barrel and it'll make all kinds of gunk which is normal. It's really not as much as it looks and running synthetic 2-stroke oil (the pennzoil isn't that high) will reduce it and is biodegradable.
I would try pulling the plug wiresone at a time while it's running at idle and make sure pulling each wire makes a big difference, indicating good spark at both cylinders. Running on one cylinder fools lots of folks into looking at the carb for problems. There is a thread in the "top secret file" at the top that is really handy at helping you adjust your carb. properly. If you haven't cleaned it out and blown all the passages out with compressed air you should anyway.
Good luck,
JBJ

 

[alangf]

Re: 1958 Johnson 18 HP starting today

I agree with JBJennings about the carb cleaning. The idea of pulling the plug wires one at a time is a good diagnostic procedure too but make sure you use the proper insulated tool to do it. If you just reach down and snatch the wire loose from a running engine you will immediately start using words you didn't know you knew. There is little to compare with 25-40,000 volts as a wake up call.

 

[samo_ott]

Re: 1958 Johnson 18 HP starting today

Sounds like the voice of experience!

 

[tashasdaddy]

Re: 1958 Johnson 18 HP starting today

there is a lot of good help in the TOP SECRET FILE. carb cleaning, adjustments, points, etc.

the water must be atleast 1/2 way up the motors leg, or you will burn up new impeller.

 

[BDbill]

Re: 1958 Johnson 18 HP starting today

Thanks for the replies. I didn't use that 5 gallon pail on the test, that was there to catch the drippings, I had a 55 gallon drum. I did check for spark on both cylinders, and both did spark while it wasn't running. If both sparked, could it still be running on one cylinder while it is running? When I do pull one while running, am I just checking for spark like before when pulling the cord? Thanks for the suggestions.

 

[tashasdaddy]

Re: 1958 Johnson 18 HP starting today

you have only one carb that services both carbs. so it should run on both cylinders, if you have spark on both. the TSF, has much help for you. suggest using this.
http://www.iboats.com/mall/partfind...gd_poid=109344&gd_row=28&**********=630754139

 

[BDbill]

Re: 1958 Johnson 18 HP starting today

When I test the cylinders, what should I look for when I remove the boot with a rubber glove? If one isn't firing, will it kill the engine? If it is working, the motor will run rougher I take it?

 

[jbjennings]

Re: 1958 Johnson 18 HP starting today

dBill,
Yes, while it's running (as low as you can get it to run consistently) take one wire off. If it dies or runs a lot rougher, you know that plug is sparking. Then do the other. If taking it off makes no difference, then you know that plug is not sparking.
Can't wait for you to report it's running. When you get it tuned right, you're going to be very impressed at how smooth it idles and how easily it cranks. It should crank up on the 1st, usually 2nd pull cold if your starting procedure is correct.
Good luck,
JBJ

 

[BDbill]

Re: 1958 Johnson 18 HP starting today

Rebuilt the carb today, looks like it was done in the last 10 years, it had a plastic float, but still needed the cleaning, plus I got a chance to inspect it, which I'm glad I did. The upper needle was stripped out, it had an aluminum like nut around it, but I doubt there was any way to adjust it. I just happened to see a 1957 18 HP Johnson carb on ebay last week and snapped it up for $20, it paid off. I also performed a compression check, both read at 90 pounds, I guess that's on the low side, but at least they are the same. I will try starting it later this week again, hopefully it idles better.

 

[coolguy147]

Re: 1958 Johnson 18 HP starting today

I agree with JBJennings about the carb cleaning. The idea of pulling the plug wires one at a time is a good diagnostic procedure too but make sure you use the proper insulated tool to do it. If you just reach down and snatch the wire loose from a running engine you will immediately start using words you didn't know you knew. There is little to compare with 25-40,000 volts as a wake up call.

i really wouldnt recommend doing this method like this guy saids thats a lot of volts i been through this before!!

IT HURTS!!

use a spark tester much safer and u can visually watch it and least likely to get hurt