1963 Johnson 40HP is affraid of water???

J

jm

Seaman
Joined
Sep 30, 2001
Messages
55
The engine starts and runs fine until I place it in the water? The only way I can get it to run is dry. It will not start in the water, and if I start it dry and back the boat down the ramp into the water the motor stalls?<br /><br />Thanks,<br />John - Dry docked in FL :(
 
T

Trent

Captain
Joined
Nov 17, 2001
Messages
3,333
Re: 1963 Johnson 40HP is affraid of water???

Time for a compression check. Also might be time to put kits in the carbs and clean them. Do the compression check first. Also make sure she is firing on all cylinders (spark check).
 
J

jm

Seaman
Joined
Sep 30, 2001
Messages
55
Re: 1963 Johnson 40HP is affraid of water???

Spark is good, all cyl's are firing. I was going to stop at discount auto on the way home a pickup a compression tester. Can you advise me on how to use it?<br /><br />I bought the motor used last year and have never cleaned the carbs. I'm sure they are clogged with garbage, the sound insulation on the casing was rotted out and all over the powerhead when I bought it. Cleaned as best I could but never removed the carb. I did spray carb cleaner into it. If you could explain the removal/cleaning process or refer me to some instruction on the net I will give that a try as well.<br /><br />Thanks,<br />John
 
J

jm

Seaman
Joined
Sep 30, 2001
Messages
55
Re: 1963 Johnson 40HP is affraid of water???

Bought the tester, just need to know how to use it.
 
T

Trent

Captain
Joined
Nov 17, 2001
Messages
3,333
Re: 1963 Johnson 40HP is affraid of water???

Remove all sparkplugs, Remove kill switch (so no spark from ignition if equipped) Install gage and turn engine over for two or three seconds (this should get several revolutions of the flywheel) and look at gage. Then do the next one. All readings should be within 15 percent of each other and over 100PSI normally but they need to be within the 15 percent for shure or you have a problem.
 
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