1972 Johnson 85 hp outboard will not go forward in lake

hey guys,

I'm a newbie and am pretty inexperienced with motors. I recently bought my boat (16' 1989 Cajun fish n ski if it matters) and took it out for the first time last weekend. Before I left, however, I started the motor with water muffs on, just to make sure I could get it to start, and everything sounded great and the prop would turn both in the forward and reverse directions, so everything looked good.

Question 1: When I put the boat in the water, I put the engine throttle in the "start" position to start it with no problems, however when I moved the lever into the "run" position I noticed that the engine idling speed dropped significantly, enough to kill the motor when I was in neutral. After restarting several times, I discovered that if I was quick enough to put it in reverse after putting the motor into the "run" position and give it a little throttle, then I was able to keep the motor running, so I guess my first question is do I need to check the idling speed of the motor since it seems to die within 5 seconds of idling in the lake? Please note that this did not happen when I tested the boat out of water when using water muffs and a garden hose.

Question 2: When I was finally running out on the lake, I was moving pretty well in the forward position, until I stopped when I noticed I had run into some shallow water. Please note that as far as I know, I didn't hit anything while I was running the main motor. I started trolling for a little while with my trolling motor since I knew I was in shallow water with stumps, etc. Anyway, when I got back out into the open water, I trimmed the main motor back down into the water, started the engine, and put it in forward, but the boat wouldn't move forward! The engine sounded like it was running fine and when I put more throttle into it, it just kept working harder. Fearing that I was on a stump or something, I put the engine in reverse and was able to backup with no problems! When I put the boat in forward again, it wouldn't move! Anyway, I ended up having to troll across the lake with my trolling motor, thank the Lord that I had a good battery on the trolling motor! Anyway, when I got the boat back home, I put the water muffs on it with the garden hose, and started up the engine and tested the forward and reverse positions and the propeller seemed to work just fine in both directions?! What gives?

Re: 1972 Johnson 85 hp outboard will not go forward in lake

Does it not try to move the boat at all in forward, not even a little bit? If it tries to go but "slips" it is probably a spun hub in the propeller. On the other hand, if it won't even try you first order of business it to check the voltages at the blue and green wires beside the powerhead. There should be zero volts on both wires in forward gear. Naturally, you have to be doing this when it isn't working.

If you have zero volts and no forward at all, then something is preventing the spring loaded shift dog from going into gear. Bad news.

Re: 1972 Johnson 85 hp outboard will not go forward in lake

It didn't seem to act like it wanted to go forward at all in the lake, but it was difficult to tell since the wind was blowing also. If it is a "spun hub" is there an easy way to check this? If so, what do I need to look for? I'm assuming I would have to take off the propeller, is there anything to that besides pulling the pin? Sorry for the stupid questions, I'm pretty new to this. Thank you for your reply.