Suzuki DF175 surging at high power setting

[Jeff J]

Just started getting a 1000 rpm surge at high power settings going across the lake. Not feeling a miss. I think about 1100 hours on the motor.
- Replaced the low pressure filter. No change.

Tank run with no load shows:
- High pressure side reads 70 psi when the key is turned on and 40 psi after the motor is started (checked at idle and 4000 rpm). No problems while checking.
- Low pressure side reads 7-8 psi up to 3500 rpm. I believe my pressure gauge connections restricted fuel flow enough to keep me from running faster. My tee reduces line size to 1/4”.

I am looking for ideas as to the next troubleshooting step.

Thanks

 

[Jeff J]

Replaced the high pressure filter and ran on the lake today. No change.

I guess it could be going into a guardian mode but not getting any alarms or lights.