Yamaha 250 HPDI loss Of Power Problems?

[bassn4life]

I have a Skeeter ZX 250 with a 250 HPDI and I am having a problem with it losing power on long runs. After running for about 20 miles or 20-25 min hard the water pressure will drop way down(Less than 8 psi) and the RPM will not go above 3000. There are no warning buzzers or odd sounds coming from the motor. I had the boat in the shop before I deployed to IRAQ and they put the motor on the computer and could find nothing wrong. The water pump is only 4 months old. I had the boat out one time before I deployed but I didn't make a long run. My neighbor took the boat out yesterday to run it and told my wife that the problem still exsist. I wanted to know if anyone else out there has had this type of issue with there yamaha motor. I am in Iraq so I am trying to get some direction for my wife to get the shop to go in trying to fix this problem.

[5 keepers]

You might try changing the entire water pump assembly. I had a buddy who had problems with psi on his yamaha and the mechanic couldn't find the problem so on a "guess", they changed the entire assembly and it worked. They thought maybe something got out of alignment/worn within and the simple impeller change would not work correctly. As far as the 3000 rpms after a long run, I have no clue. Keep us posted.

[Doug Vahrenberg]

On the RPM issue have you chnaged the High Pressure Filter. It is recommended to intial change in the 10 to 20 hours range. If it don't get the fuel it won't run.

[looking4five]

I would guess a fuel issue too (one of the MANY filters). But, It could be an ignition problem too?? A GOOD mechanic is worth his weight in gold. Hope you have one available. Stay safe & Hurry home. Hope your boat is fixed & waiting for you to use when you get back.