'71 Johnson 50 hp troubles

[97fordrunner]

Good afternoon.
First let me preface this by saying i'm fairly new to outboards especially older ones like the one I just got with my '72 Crestliner. When I first got the boat on trade it would idle but thats about it, come to find out the flywheel nut was loose and the flywheel had broken the key way- so i fixed that and got it running better but still not great. I have the OEm manual and have gone over the carb adjustments and Syncing and it does fire right up and idles but when coming off full throttle it sounds like its loading up. Also at WOT its seems like its holding back like it has more RPMs but just cant get 'em. I've been reading thru the forums and thought the timing might be the case but found that the carb/ign timing is extended all the way not allowing me to advance it the 4 deg it is supposed to instead at idle it is directly at TDC if not retarded 1-2 deg.

On another note with the cover on it idles about 200-300 RPM lower than with the cover off. Any ideas on that? it does seem like there is a lot of exhaust under the cover when I pull it off but not sure where it might be coming from, Thank you guys very much in advanced.

 

[Bosunsmate]

its probably the powerhead base gasket thats gone and sending exhaust into the engine bay.
that gaskets available, its cheap.
themotor will never run right with exhaust being sucked back into the carbs.
whats compression?
yes idle should be atdc

 

[97fordrunner]

Well i'll get that gasket ordered up then. I'm gonna pull the boat out tonight to check compression tomorrow. Thanks for the fast response

 

[Bosunsmate]

no worries, had hurricane winds here, concrete power poles snapped in two so im not going far.
check colour of your spark plugs too

 

[97fordrunner]

Update time. It wasn't a power head gasket rather the middle exhaust seal was torn. I replaced and that solved the exhaust issue. It still is sluggish through the entire RPM range and max mph is 25 and I'd think a 50hp motor on a 14' aluminum boat should do better than that. I attached pictures of the plugs after running it yesterday for about an hour. Top plug was wet and lower dry color about the same they will be in the next post. Can't post from my phone I guess

 

[97fordrunner]

While i'm trying to get pictures to load I did pull the fuel that was in it and it was indeed brown like Wiskey

 

[97fordrunner]

You can kinda see that the lower plug is Dry and the upper is wet. I'm not very good at reading plugs as far as color, What do you guys think?

 

[97fordrunner]

So I have been messing around a little more and found that my electric choke solenoid was not shutting off once it was running so I manually shut it off now once it fires up. That eliminated the bogging going up and coming off full throttle, however it still has a hesitation when at full throttle. Now it only musters about 22-24mph on flat calm water and before it was running up to about 27 and when I first had it was about 30-33. Here is a short clip of what i'm talking about. http://youtu.be/aN-3EuxdX9k Thanks

 

[97fordrunner]

Guys I was looking over my Timing and at idle it is right at TDC or 0 if not possible 1-2 deg retarded. I was looking at the timing adjuster screw and it is bottomed out advancing it as far as it can go at idle- why would this be and how? I tried backing it off just to verify that doing so would retard it further and it did. Any ideas? I know it should be set about 4 deg advanced at idle.

 

[97fordrunner]

Update. So I rebuilt both carbs top down front to back. Also rebuilt the fuel pump and I have a new primer bulb and line. Motor now idles better and the throttle when running in a barrel it is very snappy now where before it would first bog then rev up when operating it direct at the carbs. So I'm hoping to test on the lake tomorrow or Friday. Brings me to my next question is timing is still about 2 deg retarded at idle where it should be 4 deg advanced and the adjustment screw is in as far as it goes to the advanced end. What sets base timing? I haven't checked top dead center with the spark plug tool to find but that would only change where the timing marks are not the timing right? I just can't seem to find anything that could be loose or mid adjusted other than the timing pointer. Any ideas?

 

[97fordrunner]

Alright so here is a video of the engine running this morning in the tank. Again idles fine (think its a touch high) throttle is very responsive now. I did verify TDC and the timing pointer is in the right spot according the the Johnson motor method of finding TDC. And the timing screw is still advanced all the way and its just at TDC when running if not a deg retarded. What could cause this? I plan on taking it out on the lake tonight and see how it runs. Also when i pulled the plugs I did note that it is running a touch on the rich side but i'm good with that until I can work out the timing issue. Here is the Video Tell me what you think

https://www.youtube.com/watch?v=_7wT-7jdEE4

 

[97fordrunner]

Had it out on the lake tonight, ran awesome. Full throttle out of the whole, no bogging ever thru the rpms. I think I'm running a little lean the temp was warmer than I like and plugs are dry where as before they were a little damp. Which I have always gone by the saying lean is mean.

 

[Bosunsmate]

If that was idle in the tank it seems a bit fast, it might damage the gears at that speed.
ive got the 82 60hp, its basically the same motor. Make sure you replace the gaskets at the air intake if you are worried about it running lean. When i bought mine the last person hadnt replaced it and air was leaking in between the intake box and carb which leans it out a bit

 

[Bosunsmate]

Update. So I rebuilt both carbs top down front to back. Also rebuilt the fuel pump and I have a new primer bulb and line. Motor now idles better and the throttle when running in a barrel it is very snappy now where before it would first bog then rev up when operating it direct at the carbs. So I'm hoping to test on the lake tomorrow or Friday. Brings me to my next question is timing is still about 2 deg retarded at idle where it should be 4 deg advanced and the adjustment screw is in as far as it goes to the advanced end. What sets base timing? I haven't checked top dead center with the spark plug tool to find but that would only change where the timing marks are not the timing right? I just can't seem to find anything that could be loose or mid adjusted other than the timing pointer. Any ideas?

Ive just read this, hows the flywheel key? magnets in flywheel?

 

[97fordrunner]

I replaced the flywheel key when I first got it since it turned out to be broken. The one thing I haven't inspected is the flywheel and stator. I have the intake gaskets so I might give that a go. Probably could spray around the intake plate at idle with lubricated starting fluid to huh to see if there is a idle change?