1962 johnson 18 hp hard starting after shutting down when hot

[edauth]

I have a 1962 Johnson 18 horse, it starts up easily by about the third pull when I first put it in the water, but when I have been running it for a while and I shut it down I either have to choke it and pull and pull and pull usually with no luck or I can put it in gear and give it about half throttle and then it usually starts right up. Also, when it is hot and I am just idling in gear and give it a short burst of throttle and then back off it will die too. The carb has just been rebuilt, and also with my slow jet adjusted for smoothest idle I still have to have the throttle turned all the way towards the high side neutral throttle stop to keep it running, the guy that rebuilt the carb said that even with no linkages hooked up to the carb it should still run, but if I turn the throttle all the back it will die. Sorry for the long post but these old outboards are greek to me. Also it seems to run fine when it is running. Thanks guys.

 

[oldcatamount]

Re: 1962 johnson 18 hp hard starting after shutting down when hot

Look at the back of the carb under the flywheel. You'll see a black roller that follows the ignition cam when you turn the throttle handle. Notice on the cam the two small hash marks. When you turn the throttle toward fast, the roller should be at those hash marks at the exact same time as the throttle plate inside the carb starts to open. You can either watch the end of the throttle rod when turning the throttle handle or you can make a little tool out of a small alligator clip and a short piece of wire hooked to it and bite the clip onto the outside end of the throttle plate rod where it comes out of the carb body. That way when you start turning the throttle handle, the alligator clip will move and you can see it clearer. Adjust the cam so when the roller hits the middle of those hash marks, the throttle rod starts to move at that exact time. This procedure is called a "Link and Synch" and it sounds to me like your motor needs it.

 

[kfa4303]

Re: 1962 johnson 18 hp hard starting after shutting down when hot

In addition to the link n' sync which is always a good idea, you may also want to check the ignition system. I'm thinking you may have a bad coil or coil wire. They can go on the fritz if/when they get overheated. There are threads in the forums that can walk you through the testing procedures. I would also remove the flywheel, readjust, inspect/change the points and condensers too. You can get a tune up kit right here at iboats for about $20-$25. Also, take a look at the coils while you're in there and make sure they are not cracked and all of the wires are intact. Sometimes the flywheel can chafe the wires and cause them to short out. If you should need new coils you can get those here and lots of other sites for about $25-$30 each. Hope that helps some. Keep us posted.

 

[edauth]

Re: 1962 johnson 18 hp hard starting after shutting down when hot

Checked link and sync and it is good, I am not sure how to adjust points either. If I wanted to shotgun it and replace the entire ignition system what all would I have to replace and how hard will it be? I am pretty mechanically inclined but I just have never actually tore into this motor(besides putting in an impeller, and converting long shaft to a short shaft), and I have never dealt with a points ignition system. And can I get all this stuff on here? I really dont want to take the motor back to the guy I had rebuild the carb because even though he is the only one around here that works on these old motors and he supposedly does good work I had a couple problems with him, not only did he lose the hood to my motor, he had a 25hp hood laying in his shop that was in poor condition compared to my hood and put it on MY motor and said that is the hood it came in with, and I also had to fight a starting issue because he had told me that he set the needles to 3/4 turns out but after a lot of aggravation on my part did I find out that the slow speed needle was over 11 turns out when I got it back from him. AARRRGGGHHH. Thanks for the prompt replies guys I can tell this is a great forum even on my first post.

 

[kfa4303]

Re: 1962 johnson 18 hp hard starting after shutting down when hot

Hi edauth. It's not hard to replace the ignitions in these old gems at all. It's actually pretty interesting. You can get all the parts you need for less than $150, or so. You can get virtually all the bits you need right here at iboats. Here are a couple of great links that can walk you through everything you a full blow tune up. Once you get the gist of them you'll appreciate just how ingenious they are and why so many folks like and prefer them to modern motors. If you have any questions feel free to ask. You've got a great motor that's well worth the effort if the compression is good. All the rest can be fixed pretty easily. You may have to buy a few tools, but they're pretty cheap and well worth the money. You'll need a fly wheel puller and a set of feller gauges, but the only other tools you'll need are a flat head screwdriver, a couple wrenches and a socket or two. Best of all, once you can fix one of these Johnsons form the 50's-mid 70's you can pretty much fix 'em all. Check this link out and get back to us. It's for a different year and model, but the fundamentals are all the same. Good luck.

http://www.duckworksmagazine.com/07/columns/max/index1.htm

 

[edauth]

Re: 1962 johnson 18 hp hard starting after shutting down when hot

I have or can get all the tools, thanks for the link, that is some very useful information, I think I am going to start with replacing the coils and go from there. I will keep you guys posted but it may be a week or so til I get them installed and tested on the water.