Fluctuating RPM's when turning to Starboard

[Albemarle Bob]

I have a 2000 5.7 GSI PEFS with the DP-SM Outdrive. Just had a servicing which included all the ignition parts including coil, lower unit lube etc. When at idle, either in the water or when flushing, a slight turn to starboard will cause the RPM's to fluctuate. Turning back straight remedies the issue. Turning port is fine. Am I looking at a restriction in exhaust happening when turning port or is it possible the u-joints can bind in only one direction. No other noises or evidence, just fluctuating RPM's.

 

[redneck joe]

fluctuating per tach or ears?

 

[Albemarle Bob]

Both by ear and the Tach although I know the Tach is questionable. Friend at work suggested steering. I checked the power steering fluid. It was very low. Filled it up and ran it a bit moving from side to side. Still have a little hiccup going from straight to slighty starboard. Once I get past that point the RPM’s even out. Never got the typical noise heard on vehicle power steering. No obvious sign of a leak but I'll have to monitor the level.