1960 Johnson Seahorse 18hp Model FDL-14 Problems

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who pooted?

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Guys,
I've got a 1960 18hp Johsnon Seahorse that pushes my 1436 fully loaded at a gps of 23mph..........prior to hitting a floating log! My engine raised out of the water for a few seconds, and then i ran back to the ramp. Power seemed to decrease as i was returning. I got home inspected LU for holes, loose nuts, etc. Didn't see any issues. I went ahead and changed out LU oil, and there were no problems with it either. Problem I'm having now is boat will run back to original speed, but starting is a little bit more difficult (electric start). Also, last couple of trips i was WOT and then my speed began to decline from 23 to 18, then to 14, and finally stayed at 11mph. It did that on the first trip, and then started fine for the second trip only to decrease in speed again on the way back to the ramp. I replaced all fuel hoses on motor 6 months ago, and had the engine tuned 8 mos. ago (new impeller, carb job, etc.) My motor has always been difficult to start with the rope, but usually starts right up with the electric start with a little choke. Sorry to ramble, but does anyone have any ideas what may be causing the speed decrease?
Thanks to all,
Adam
 
Check your oil in the gearcase again and see if it has a gray color and possible metallic debris in it. Rotate your propshaft while viewing from directly aft and see if it is bent. Check the area nearest the gearcase where the outer diameter of the propeller rides and see if there are wear marks anywhere. Rotate the prop while inspecting this area to see if the prop is touching anywhere it should not be.
 
Maybe a coil going bad, loosing fire when it heats up. Have you checked them, if one or both are cracked replace it/them.
 
Pappy I will check the LU again this weekend along with the propshaft etc.

BBstacker1 I don't want to tear into the motor until i receive the repair manual from Jim. I'm a little nervous when it comes to tinkering w/the engine unless I have pictures/manuals. I guess since it's my only motor I don't want to be totally land locked in case i mess it up. Funny i never hesitate to start tearing into my lawn equipment!

Thanks guys- Adam
 
You can pull your prop off and make sure you didn't mess up the hub. You might have stripped it when you hit the log.
 

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