1954 Johnson 5.5 compression questions

[Rayzor]

I have a 1954 Johnson 5.5 hp. Its been sitting for a long time and was locked up. I shot penetrating oil in it and worked the flywheel back and forth by hand until it spun over freely. I to ssed a compression gauge on it and both cylinders gave up 90 psi compression. Is this to low or should I try to start it?

 

[jonesg]

Re: 1954 Johnson 5.5 compression questions

It might need a water pump but the compression is good for hand starting.
A carb rebuild wouldn't hurt either.

 

[Barnacle_Bill]

Re: 1954 Johnson 5.5 compression questions

Yeah, 90lbs is good for that old motor.

 

[1946Zephyr]

Re: 1954 Johnson 5.5 compression questions

Schitt!! 90 psi is awesome. Especially if both cylinders deliver that evenly. Post some pics of that bad boy.

 

[Rayzor]

Re: 1954 Johnson 5.5 compression questions

Schitt!! 90 psi is awesome. Especially if both cylinders deliver that evenly. Post some pics of that bad boy.

Well, I will post a pic or two if I can get it running. I took apart the carb and cleaned it real good. Seemed in good shape for its age. I filled the tank with fresh fuel and it has good spark. Will it even sound like it wants to start? No... I am at a loss, has fuel has spark, the reeds seemed ok so I assume its getting air, but no ignition. Nobody around these parts wants anything to do with trying to make it run so I am now giving it a blank stare. Anybody in Oregon speak vintage Johnson?

 

[samo_ott]

Re: 1954 Johnson 5.5 compression questions

That's almost too good compression. Is the guage accurate?

How did you test for a good spark? It needs to be done with a proper spark tester with a good 1/4" gap, not tolding the plug by the block. A weak spark has fooled amny a folk before. What's the histopry of the engine? Are the coils new? If you remove the pull start there's an access hole you can look inside to see the coil condition. If any cracks or sweaty looking they should be replaced.

BTW, I have the parts manual for it if you want it PM me with your email addaress and request.

 

[Rayzor]

Re: 1954 Johnson 5.5 compression questions

Thats the compression I got out of it when I had penetrating oil soaked cylinders. I checked again after a few thousand pulls starts and It blows 75 psi. They are dead even side to side. When I say good spark that was tested 2 ways, one was me nearly bighting the tip of my tongue off as my buddy lit me up with the pull start before I was ready . And the other was by laying the plug on the block. Nothing is new on the motor and its been sitting since the late 60s. I would love to know its history but the owner is gone now. I plan on pulling the flywheel in the morning so I can take a look around better. Thanks for the parts manual offer pm sent.

 

[1946Zephyr]

Re: 1954 Johnson 5.5 compression questions

Those old green Johnson 5.5's are great little motors. I have a 55 model myself. The compression on mine isn't near as good as your's, but it still runs good. I have it on my future restoration list, once I get my 1941 HD-20 finished.

 

[Rayzor]

Re: 1954 Johnson 5.5 compression questions

Yea, I really like lookin at it. I have a 57 3 horse that really seems to draw attention at the gas pumps and boat ramps. I like the fact that there is nothing plastic to fall off when they start. I need to make this 5 run as fishing season is almost here and the 3 hp just wont cut it for getting me across the lake quick.

 

[Steve A W]

Re: 1954 Johnson 5.5 compression questions

Rayzor
Here's three sites I recomend, I learned a lot from them when I
rehabbed a 55 Johnson 5.5hp m/CD12.

http://www.precisionservoutboard.com/Information/ArtsFivePointPlan/tabid/65/Default.aspx

http://forums.iboats.com/showthread.php?t=158086

http://www.duckworksmagazine.com/07/columns/max/articles.htm

On the Duckworks site, read the "Start to Finish" articles.
He revives a 55 CD12.
Good Luck with Your motor, I really like My CD12!
Steve A W

 

[Rayzor]

Re: 1954 Johnson 5.5 compression questions

Well, I think I nailed the issue of why no starting. I pulled the flyweel off and both coils look like broken eggs. They are both just shattered. Strange that they send a spark to the plugs still. But I believe thats the problem so I will begin by replacing them and throwing a carb kit at it.

 

[tx1961whaler]

Re: 1954 Johnson 5.5 compression questions

Might as well replace the water pump impeller while you're at it....