BF225 no power amp TPS out of range

"GREAT SITE! I read a bunch of

"GREAT SITE! I read a bunch of past posts that nipped at my problem, but I hope to get some opinions unique to my situation.
'02 BF225 idles fine, but under load produces ~2200 rpm and will not plane my boat, revs up and down by itself, dies, and looses power as you add throttle past it's very slow "happy place." Rev in nuetral gives a lag before coming up in RPMs...not responsive.

It passes all HDS checks both on land and under power in the river. Only parameter out of spec according to my tech is the Throttle Position Sensor (TPS) voltage is out of range.
Because the HP filter was slightly collapsed and corroded when I changed it, he checked fuel pressure and only got ~30psi with the max during the test ~35psi.

He is still working the diagnosis, not willing to declare victory with the TPS just yet, but I noticed a few other subtle signs. 1)old plugs were black with build up, like a 2 stroke's plugs. 2) black soot under cav plate after idle 30 minutes in tank. 3) tech noted exhaust mans were slow to warm up under no load, possible thermostat issue.

I want to pull VST, but most of the bolts down low at the rear are pretty corroded. Been spraying with penetrating lube, not the bedroom kind. I'd like to avoid snapping bolts 'til it's necessary. My drain screw on the pump is rusted and won't turn. Pumping the ball hard while running doesn't change things, and it does not deflate under suction.

That's what I have for now...
THANKS!
Merrill"

"One note on #3, any comment o

"One note on #3, any comment on the notion that rich mixture = low EGT at idle. I'm guessing that the exhaust would smell rich, which it doesn't, in order to lower EGT enough to slow warm up.
Note on #2: midsection has coating of black soot when you pull the side covers off, is this normal after 200 hours?"

"It sounds like the tech is go

"It sounds like the tech is going down the right path. Once the TPS and the temperature issues can be part or all of the issue. I also assume he did a cylinder stop test which turns off the injectors one at a time.

Generally, if you get beyond the sensors being out of range, runnability problems tend to be fuel related or something physical on the engine.

The fuel pressure on the high side should be between 41 - 48 psi with the pressure regulator vacuum tube disconnected.

You have to fix the obvious before delving into other options. Let the tech do his thing..."

Dear merrill You have to do a

Dear merrill You have to do a thorough cleaning to your throttle house . includes the iac and then to chek the ho2 sensore.

"merrill, my dad is having the

"merrill, my dad is having the same problem with his motor and i was just wondering what happened with yours and what all you had to do. The honda techs in TN really dont want to work on the motor anymore since it has been passed around to almost all of them."

"At this point, the HDS is ign

"At this point, the HDS is ignorant of my problems. So my plan is to go to autozone to buy oxygen and both temp sensors for honda odyssey. Get those replaced and out on a sea trial well before striper season.
I've since replaced the fuel system (all new injectors, pump, & vst) which helped tremendously, but still a little off. New TPS did not help, but the fuel map is determined by numerous sensor inputs, any of which can cause the problems."

"One more note: the new VST as

"One more note: the new VST assembly had the fuel float out of adjustment. Gas was running out the motor cowling into the water. Had to pull it back out, tear it apart and adjust the float with dial indicator depth gauge. Service manual lists the proper settings.
Spent $1000 on what is essentially a big heated carb bowl, just to have it be messed up.
Starting to wish I'd kept my loud and proud mercury!"