Adjusting TPS, and/or removing throttle body

Hello folks,

I realized through last season that my starboard TPS needs to be adjusted. No wake will activate only if I lost the idle way down, below 1550.

I have explored and actually removed injectors before but even with the service manual it has been somewhat haphazard.

For those of you that have successfully removed and reinstalled the throttle body, what are the tips that you wish you had known before you did the job?


I really don't see much access to adjust the tps without removing the throttle body. Is this right? Is there something I'm missing that might allow you to adjust TPS while the throttle body is still installed?

Thanks in advance for your knowledge and insight.

Maybe @finnrigged ???

It has been many years since I replaced my TPS so please bear that in mind.
I do not recall there being a means of adjusting it. I do recall that I was able to remove the screws that secured it by drilling holes in the side of the air cleaner box. This allowed me to NOT have to remove the throttle body. I then sealed the drilled holes with silicone. Please let us know if you find a better way.

Lol, I was considering that option also. Do you recall a trick to disconnecting the connector in place?

I tried to disconnect from the harness while the tps is attached and I could not.

Hmmm...sorry, it has been a long time. I don't recall.
If you go the route of pulling the fuel rail be EXTREMELY careful with the Manifold Pressure Sensor. You can see in the picture it will break easily due to heat fatigue. You will need security Torx bits for the TPS.

Thanks for all the tips. Mischief managed.

Fuel line removed, maf connector, tps connector and air bypass electrical connector removed, then 4 bolts for the flame arrestor, the 8 bolts for the throttle body, and a little jiggling to get it loose, lift the back and pull out fuel rail inlet of the air box.

Adjusted and checked with YDS, and no wake is working as expected!

Sorry, just saw this post tonight! Well done!

Beachbummer said:

Thanks for all the tips. Mischief managed.

Fuel line removed, maf connector, tps connector and air bypass electrical connector removed, then 4 bolts for the flame arrestor, the 8 bolts for the throttle body, and a little jiggling to get it loose, lift the back and pull out fuel rail inlet of the air box.

Adjusted and checked with YDS, and no wake is working as expected!

Click to expand...

Were the screws on the TPS loose? How far off was the TPS?

They were not loose, but when the head was replaced last year the tps sensor was reinstalled just slightly off spec.

One thing to keep in mind, as you may bump the key to wake up YDS as you are adjusting, mind the fuel hose, which should be reconnected to the throttle body or plugged some other way, otherwise an unexpected bit of fuel will come out of the disconnected gas hose. Obvious in hindsight, but easy to miss at the time if you are not paying attention.

Beachbummer said:

They were not loose, but when the head was replaced last year the tps sensor was reinstalled just slightly off spec.

One thing to keep in mind, as you may bump the key to wake up YDS as you are adjusting, mind the fuel hose, which should be reconnected to the throttle body or plugged some other way, otherwise an unexpected bit of fuel will come out of the disconnected gas hose. Obvious in hindsight, but easy to miss at the time if you are not paying attention.

Click to expand...

Experience; Noun, is what you get when you don’t get what you want.

Best way to gain knowledge is through others mistakes. Less good way is through (our) own mistakes.

I wonder if these Yamaha jet boats are the same as the Yamaha Waverunners with the exact same motors....in that IF you put the throttles in the wide open position and crank the starter, our Waverunners will not send fuel through the fuel rail as a safety precaution so that it doesn't send you flying off the seat suddenly on an accidental startup. The throttle position sensor says, " nope...your throttle is open so I'm not gonna send you off the back of the boat".

I was able to adjust the tps on mine last year by drilling holes in the air cleaner assy. I then used the YDS & a multimeter to adjust it without pulling the throttle body.

Does any of this have anything to do with engine light blinking code 1-8?