not turning up RPM

[Captbrit]

I have a 31' Jupiter with twin DF300z Suzuki. The port motor will not turn up full RPM. I have changed the racor filter, the high speed filter, the in line filter on the engine and changed spark plugs. Can you give me any other suggestions to help me troubleshoot the problem?

[Solarman]

It might help to let us know the rpms your port motor is going to, and if anything preceeded this situation? Also age of motor? Did you purchase fuel at a different station, separate fuel tanks? Any diagnostic codes?

Post back when able to let us know.

[Captbrit]

The engines are 2011 with approximately 1300 hours. They do draw from different tanks. The port tank (the one the problem engine is drawing from) did have some water in the racors and a very small bit of water in the engine filter. No diagnostic codes are showing up other than 3-6 which only flashed for a minute. The boat has been unused for 2 months. It ran fine the last time. It idles very smoothly and even runs smoothly up to about 3600rpm where it still sounds good, just won't gain rpm. It will slowly gain rpm up to 4000 rpm if the throttles are taken off sync and jockeyed slowly. Also the sync isn't working

[Captbrit]

Still hoping for some advise on this one.