Throttle position sensor Yamaha 225 excel

dhawk

Cadet
Joined
May 12, 2007
Messages
23
Can anyone tell me how to test a tps for a 225 excel? There was a diagram in a Clymer's manual and it was not clear. I applied 12 volt to the tps with a jury rigged test harness and I think I ruined the sensor or the computer by inadvertently crossing some wires. Also, when I disconnected another sensor, the thermo-sensor, the motor ran a lot better, leading me to believe that that sensor was defective. However, there was no difference in performance when I connected a used replacement sensor to the ecm. So, I eliminated that sensor as the problem. I ran the motor today and there was no performance difference with the tps connected or disconnected. If the computer is bad, then all I'm doing is replacing sensors to no avail. I could go broke throwing parts at this. I know this is a long first post, but I do appreciate any help out there. Thanks is advance.
 

yamamarinetech40

Petty Officer 1st Class
Joined
Dec 17, 2006
Messages
328
Re: Throttle position sensor Yamaha 225 excel

Why don't you start from beginning and tell us what the motor is doing instead of tellin us what you're doing and maybe someone can help....you probably did screw something up with 12 volts....
 

JUSTINTIME

Captain
Joined
Sep 2, 2006
Messages
3,284
Re: Throttle position sensor Yamaha 225 excel

Can anyone tell me how to test a tps for a 225 excel? There was a diagram in a Clymer's manual and it was not clear. I applied 12 volt to the tps with a jury rigged test harness and I think I ruined the sensor or the computer by inadvertently crossing some wires. Also, when I disconnected another sensor, the thermo-sensor, the motor ran a lot better, leading me to believe that that sensor was defective. However, there was no difference in performance when I connected a used replacement sensor to the ecm. So, I eliminated that sensor as the problem. I ran the motor today and there was no performance difference with the tps connected or disconnected. If the computer is bad, then all I'm doing is replacing sensors to no avail. I could go broke throwing parts at this. I know this is a long first post, but I do appreciate any help out there. Thanks is advance.

throw the clymers away and get a factory manual
 

JUSTINTIME

Captain
Joined
Sep 2, 2006
Messages
3,284
Re: Throttle position sensor Yamaha 225 excel

shoot me an e-mail i might have the factory one in pdf
 

dhawk

Cadet
Joined
May 12, 2007
Messages
23
Re: Throttle position sensor Yamaha 225 excel

ymtek:

Symptoms: Motor ok cold. Runs about 3 minutes, warms up and sputters and stalls out. Max rpm in water 2k. With no thermo-sensor: idle smooths out, but is high -1100 rpms -usually 850. Acceleration choppy, motor bogs down. Max rpm 5k.

Quick history: Throttle position sensor checked with 12 volts. May have crossed wires. Last season - max rpm 5.6K. with intermitent drop of 2-300 rpms at wot. It was this minor problem that motivated me to check main jets before I splashed this year. Should have left well enought alone. New life rule: don't touch parts secured with loctite.:redface:
 

dhawk

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Joined
May 12, 2007
Messages
23
Re: Throttle position sensor Yamaha 225 excel

JUSTINTIME Sent you a PM
 

Ray Neudecker

Lieutenant Commander
Joined
May 25, 2004
Messages
1,656
Re: Throttle position sensor Yamaha 225 excel

It appears that what started as a fuel restriction has been turned into some thing else. You can basically test the TPS with an ohm meter. Attach the meter to the two legs of the TPS and see if the resistance varies with the movement of the arm. You will need the Yamaha manual to properly test the other components of the system.
 

dhawk

Cadet
Joined
May 12, 2007
Messages
23
Re: Throttle position sensor Yamaha 225 excel

To those that replied, thank you. The problem was the tps. In the water today and it ran like old times:D
 
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