1973 85hp Merc dies WOT

Greetings, I have a 1973 Glastron GT150 15' with an 85hp Merc outboard of the same year. Everything runs well, except when skiing with about 450lbs in the boat, when I go from lowest speed to WOT to plane out and get the skier up, the motor just dies. If I go slowly (not quite fast enough for a skiier), it will struggle past a certain point and then go at full speed, but I can't get a skiier out of the water which is the reason I bought the boat. I changed a couple spark plugs that needed replacing, put in a new fuel line (the gas can is not built in) and impeller this spring, and it does not seem to have this problem with nobody skiing, so I think the load is what's causing it to die, but I just don't know why. Does anyone know what could cause the motor to act this way? Any advice would be much appreciated. Thank you in advance,

Scott

Re: 1973 85hp Merc dies WOT

Try backing out the idle mix screws 1/4 turn and see if that helps. Try 1/2 turn as well. Try sqeezing the ball a few times. If no improvement test for good spark on all 4. What is WOT rpm's? Check compression. Good compression and good spark means its a fuel problem. Time for a carb overhaul. Make sure you blow out all the passages with compressed air.
Check your link and sync as well. There is a good article in the FAQ section by Clams Canino on ho to do this.

Re: 1973 85hp Merc dies WOT

Thanks for the info redjmp, Im going to rebuild the carb this weekend, does anyone on here know of a good place to get a carb kit for this year of motor? Also, I think my guage must be broken because it tells me that WOT rpm's are around 3,000, which is way low from where I understand it should be. Any other suggestions? Thanks again for the response, there's a great wealth of information on here!

-Scott

Re: 1973 85hp Merc dies WOT

N A PA auto parts can order them .