Yamaha hpdi z200txrz running lean

Bengal

Recruit
Joined
Oct 2, 2018
Messages
5
I have been completely through my entire system and cannot understand why I am getting a reading of 0.01v at 2500rpm+. At idle and when I slow down the voltage will go up to 0.4 to 0.7v. I am reaching full rpms and everything sounds good but i am concerned about the lean reading since i just replaced a powerhead due to lean conditions on the other motor.
Engine: 2001 Yamaha HPDI z200txrz
Things I have done:
1. New o2 sensor
2. New LP fuel pumps
3. New vst pump filter
4. New water seperator on engine and after gas tank(yamaha 10 micron)
5. New spark plugs
6. Verified ignition system and replaced one of the plug boots.
7. New oil pump, filter and sensor on remote oil tank.
8. Fuel injectors cleaned and flow tested.
9. New thermostats and water pump.
10. Fuel pressure at vst 50psig.
11. High pressure pump is at 692psig.
12. TPS sensor is set at factor specs.

After I have done all of this I keep getting a voltage reading of 0.01v above 2500rpms and cannot understand why I am showing lean. On my other engine, I show 0.43v at 3000rpms which I believe is perfect
 

rejesterd

Petty Officer 2nd Class
Joined
Sep 20, 2018
Messages
142
Check for air leaks along the intake manifold and the fuel rail. Spray something flammable like brake cleaner or starting fluid, and see if the idle speed changes.

If it's not an air leak, try swapping out the ECUs between the motors (if they're the same). Could be a faulty ECU. If you can't swap them, the service manual might tell you how to check it out.
 

Bengal

Recruit
Joined
Oct 2, 2018
Messages
5
Forgot to mention that the ECU is new too because the oil system would not transfer.
 
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