1956 Johnson 15hp tune up?

[Superbigstevie]

I have been gifted a 1956 15hp Johnson model FD10L. I think I need to overhaul the ignition system? I have rebuilt the carb and two line tank it will now start on the second pull! It has 85# on the top cylinder and 87# on the bottom. With the exception of the prop and the lower end oil every part is original. Even the pull rope! I think it is under 300 hours.<br /><br />Question #1 After about 1/2 hour of operation it will not restart. Put in new plugs (J6C) it fires right up. Is the spark week? What parts do I need? Where to find? How much?<br /><br />Question #2 How do I hook up a shop tachometer? What is the max RPM? I have read 4000-5500. <br /> <br />Question #3 What is the aprox value of the outboard?<br /><br />Question #4 What do I need to change the impeller? Cost? Source?<br /><br />Thanks

 

[alcan]

Re: 1956 Johnson 15hp tune up?

Hi Super<br />The first thing you need is a manual. You can order one here from Iboats or pick up a copy at the library. Almost all of these fifties and early sixties motors need new ignition coils. The old coils swell, then split/crack. A lot of times thay will spark just fine for a short while. You can order all the parts you need from your Napa auto parts dealer. You will most likely need 2 coils, 2 point sets, 2 condencers, 2 spark plugs and at least a water pump empeller. You may want to get the entire pump kit, as long as your at it. The value of this motor depends on what it is worth to you. I usually spend around $150. on parts to service and tune one of these models, not counting labor. So I figure a ready to go motor is worth at least that much. I have found it's usually hard to get much more for them. Remember I am talking ready to go.

 

[BillP]

Re: 1956 Johnson 15hp tune up?

That's a good motor. I had one when a teenager and ran the pixx out of it without a wimper. Like already posted, I suspect the coils too. Be sure to replace the condensers at the same time. If the points aren't pitted they can be dressed. Very easy motor to work on.

 

[Lark40]

Re: 1956 Johnson 15hp tune up?

Regarding hooking up a tachometer, you need a special one.<br /><br />You have a two cylinder two stroke magneto ignition engine with points for each clyinder. Not something that a car will have....<br /><br />There is a tach built by TinyTach. Their web site is www.tinytach.com. Call them and they will walk you through finding the correct model.

 

[Superbigstevie]

Re: 1956 Johnson 15hp tune up?

Thanks for the info!

 

[Superbigstevie]

Re: 1956 Johnson 15hp tune up?

15 is running great. starts on the first pull. the trout better look out!