F-150 throttle body valves--pics

[skipper2101]

hey guys,
i am new here and could use some help if possible. i have a 2007 striper 2101 with a Yamaha f150 with a 15m prop. i have been looking for my missing rpm. i believe that my throttle body plates are the problem. it appears that at wot they do not open all the way nor do they even come close to the stops. when i am at full throttle the engine turns 5600 rpm however if i put some extra weight into the throttle i get 5700 and i know the engine has more to give. i have pulled the airbox and have seen this happening. i have called many shops and they say well as long as you are around 5500rpm you're okay. i think that this is B/S. i thought wot meant wot not 70% of wot is wot.
i have tried to adjust as per the seloc manual however i cannot get the plates to open any further while still achieving full closure. maybe adjustment at throttle? engine incorrectly rigged? i have noticied the these boats are rigged very conservatively. any ideas. here are some pics.
first pic: throttle closed
second pic: my throttle wot

[jb123]

you might be able to undo cables @ motor and adjust out but i doubt itll make any difference
running it at higher rpms than 5600 will just shorten the life of the motor

[skipper2101]

operating range as per yamaha is 5-6k, with 6k being better than 5000 or 5600 so as to not lug the engine and start making oil i thought.

[TownsendsFJR1300]

I'd try disconnecting the main throttle cable to the engine and then try the FI body thottle linkage and see how far that opens the blades... That'll at least narrow down if its in the linkage or the throttle cable to the console.

If its at the engine itself, check for for adjustments there are in the linkages.

I suspect its more likely in the main control cable to the engine not extending fully...

When seated in the main hold down (the outer part of the cable) the center should drop straight down on the pin for the engine throttle if adjusted properly...

There's also an adjustment for syncing the two throttle bodies however you need a manometer to check that. Is the other throttle body about at the same position at WOT?

[skipper2101]

thanks for the help guys. i tore apart the throttle control at the helm and had found the throttle tensioner screw had backed out displacing the block inside the unit thereby restricting full throttle travel. i now have true wot at the throttle body.
thanks again

[99yam40]

Good to hear, how much did it increase the WOT RPMs?

[skipper2101]

Going to test tomorrow am, will post results asap.

[TownsendsFJR1300]

Excellent!!

[skipper2101]

results are in: 300 rpm increase and little over 3 mph gained. engine now "feels" like it can breathe again.

previous performance avg rpm 5600
avg speed 35 mph

current performance avg rpm 5900
avg speed 38 mph