89 Johnson 60hp 3cyl cutts out bad under heavy loads

Robhotdog

Recruit
Joined
Jul 2, 2006
Messages
1
Hello, Is there anyone that can steer me in the right direction? Heres what I got. Its a 60 hp on a 18 ft pontoon. Normally runs about 25mph w.o.t. BUT,(this just started this year) If I put 6 or7 people in it, it runs as well as to be expected for the weight for about 10 min, then starts cutting out BAD!..I can throttle back to about 1000 rpm and it will hit on all cyls again.If it dies I put it into neutral-fast idle, try to rev it to clean it out and does the same thing in neutral...Wierd huh?I can only creep along, barely above idle, Like hitting a revlimiter..too far and it starts missin, back-er down a bit and its all good at 7mph. I changed plugs, checked fuel filter, its ok! the lines are new, even tryed to pump the bulb while this is goin on.No change. I dont think its fuel delivery..? hears the wierd part, I can unload the boat..after finally gettin to shore, Back off and it will haul ass again! Some one told me that my reeds were worn out....?? Im wondering if its heat related? I havent put a pump in it for 5 yrs....I dont think its o-heating...I heard the alarm go off last year when I was towing a broke jetski and a bunch of people alittle too hard..cooled her down and got back normally.... HELP ME SOMBODY! Id like to take more than 500lbs in my boat. (wonder if its wires? there stock) thanks, Rob
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: 89 Johnson 60hp 3cyl cutts out bad under heavy loads

Hi Rob

I think it is overheating when you get the load on the boat. Just like it did when you were towing the broken down ski. Make sure your warning horn is working now and change out that impeller. 5 years is a little long....
 
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