150 gt troubles

ok gentleman, i have a 1986 johnson v6 with WOT issues. i have done the obvious things like check the fuel filter, replaced some leaking fuel line. in addition i rebuilt the carbs, checked the link and sync the best i can, checked compression (95 on each cylinder), replaced the coils and packs. i'm at my wits end, the engine will rev get when it is in neutral (can take it up to 5500 rpm or so by hand operating the throttle) even had a friend put it in a tank to run while in gear and it does fine there also but when it gets under a load i can only get about 3000 rpm WOT. anyone have any other suggestions???? i've even check all the ground wires to make sure they are clean and tight. tried to slam the throttle wide open and tried to ease into it and still the same result. any help or suggestions would be greatly appreciated. gettin close to taking it to the local dealer for diagonsis.

Re: 150 gt troubles

Check for a good strong spark on all cylinders.
Make sure the throttle plates are opening fully.
Check the timing and make sure its reaching full advance.

Re: 150 gt troubles

What about compression here, what were th reading's?

Re: 150 gt troubles

compresion is 95 psi on each cylinder

Re: 150 gt troubles

r.johnson i'm up in raymond. are you a good mechanic? maybe you want to take a crack at it?

Re: 150 gt troubles

nogo: I'm in the phone book for LaPorte City. Give me a call, and I will dicuss this with you. I'm listed under Robert Johnson.

Re: 150 gt troubles

compression is a little low.. id like to see 110 Try decarb.

Re: 150 gt troubles

Is this boat new to you? Just wondering if this has always been an issue since you owned it, or if it used to have no problem hitting the recommended WOT rpm?

Re: 150 gt troubles

no i've owned the boat 86 stratos 18 ft 179v for about 4 years now. didn't get any use last year, was in storage at my folks place. as far as wot operation ran fine previous years, always seemed a little slow on reaching full wot but when it would reach the hump and take off it would get gone. when i replaced the coils i noticed the back side of them were melted like the power head was burning them up. maybe i have more trouble than i realize?? would a different pitched prop cause any of the wot problems?