WOT Problem

[booger man]

Ok i have a 1991 9.9 johnson manual start tiller that was upgraded to a 15hp the problem has stayed even after the upgrade.the motor starts every time on the second pull but at wide open throttle it starts to bog down ,let the throttle back a 1/4 to 1/2 inch and she perks right up again.......I want to be able to twist the throttle all the way and have full power...The tiller has the throttle on the outside grip and a idle adjustment inside at the end of the handle...I have compression,fuel and spark what am i missing

 

[Dhadley]

Re: WOT Problem

Welcome!!<br /><br />Its probably a problem related to the carb. We really need more info about all the changes you made. Truthfully, anytime we try to modify any motor, that motor must be running perfectly to start with. You mentioned it was doing this before the mods. When was the last time it ran good? What happened after that? In storage? Tune up? Anything?

 

[booger man]

Re: WOT Problem

it's always done this even after the shop put the 15hp carb upgrade to it ,the prop is a new 9 1/4 x 10 and it does it weather loaded with 3 guys and gear or just me in the boat...out of the water[with the ears on} it will scream and not bog down,but under load the throttle is a half inch from wot and does great,but twist to full i lose rpm {bogs}....I get 19.2mpg by my gps with just me in it 11mph with 2 people...The boat is a 1959 lonestar semi-v aluminum modded to a fishing rig {floor.pedestal seats,livewell,2 batteries up front and bow mounted 50lb trolling motor...She is far from light{maybe 575lbs with just rigged equipment}i know when stripped down to just the boat when i prepped it for paint she is light enough to flip around by myself} what else do you need regarding info....