1963 Johnson 5.5 bog

[rokee]

First post, and this one should be interesting. I recently bought this unit and today was the first time for it on the lake, i have ran it in a test tank a number of times and it runs great with no load. When i put it in the lake today, i put it in gear and it bogs, in other words it wont rev out. I brought it home and in a bigger tank i now get the same results. I checked out and cleaned the carb. everything checks good and clean inside. Then i moved to ignition its now all in spec. coils are new style, same results. Im lost

 

[F_R]

Re: 1963 Johnson 5.5 bog

Chances are about 99% it is running on one cylinder. Cleaning the carburetor won't fix that, as you found out.

OK, so did you check the compression before you started? May have a blown piston..or head gasket...or something else.

Have you checked the spark? Should be capable of jumping a 1/4" gap in open air. Jumping the plug gap when laid up against the head is not a spark test. Speaking of spark plugs, you have tried new ones......haven't you?

Never start doing repairs without first determining what needs fixing through simple tests such as this. Otherwise, you only compound the problem.

 

[The-Machinist]

Re: 1963 Johnson 5.5 bog

Have you checked the strength of your spark? It should be able to jump at least 1/4". Maybe one of those new style coils took a dump

 

[rokee]

Re: 1963 Johnson 5.5 bog

Being a automotive technician, I did all thos basic checks first thing, out on the water before i even brought it back home, even the compression test out on the water (when you take a motor out for the first time allways go prepared), i wasnt happy with the compression numbers at 80-85 psi but didnt think it explained the really bad power loss, considering if compression were really bad it wouldnt start so easy. I was wondering if there might be an issue with the LU, im unfamiliar with them besides doing regular fluid replacment, ive never even needed to reseal one before.