Re: 1957 Johnson 5.5 sea horse
Re: 1957 Johnson 5.5 sea horse
Here's what I do when I get a "new" one.
#1 . check compression-- if only to get a baseline measurement to compare later.
#2. Pull the flywheel (10$ harmonic balancer puller from o'reillys auto parts) and check(in your case---replace) the coils, condensers, and points.
#3. Rebuild the carb. --in your case, you'll have a cork float and you want to get the kit that comes with a new PLASTIC float
#4. Replace the water pump impeller. Most experts recommend replacing the whole water pump housing and impeller.
#5. Reseal the lower unit if the lower unit oil doesn't look good. It probably won't.
There's no need to rebuild the whole motor if it doesn't need it. Replacing parts that aren't worn out or bad won't make it run any better.
Except for the head gasket, I use the old gaskets to trace out new ones in felpro black gasket paper that I get at the auto parts store. I like 1/16 thickness. I don't use liquid gasket sealer on anything except the lower unit halves and you supposedly don't need it there with new seals.
Changing the lower unit seals is the most annoying job but not that bad. Just ask questions when you run into something you don't know how to do like changing the shift shaft seal or getting out the old prop and drive shaft seals. If you don't have at least 65 lbs. of compression you might think about a used powerhead. But compression gauges are often wrong so if it seems low, don't trust it. ALso, usually when compression is bad one cylinder will be a lot lower than the other. IF they're even, a lot of times the comp. is o.k., it's just the gauge or the gauger is wrong. DOn't forget the "awakening a sleeping outboard" thread in the FAQ's forum.
GOod luck,
JBJ
