Water Pressure?

[KHill3611]

Ok guys, I hope one of you can help. I have a 07 ZX255 with a Yamaha 225 HPDI, My water pressure keeps dropping. One time it may be 12-14psi@5200rpm & te next it will be 6-8psi@5200rpm. I had the water pump changed & I changed the popit valve,seat,& spring. when it first started doing this I cleaned the popit valve & it helped for a couple trips out then it would drop again. I even flushed the system when I had the popit valve out. My water temp runs 132 deg so I think it is moving the water plenty good. Any suggestions?

[kymike]

what is the lake temp . mine get low this time of year ky lakes at 88 to 91 temp.

[KHill3611]

87-92 deg

[Neilslure]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by KHill3611 &raquo;</td></tr><tr><td class="quote">87-92 deg</td></tr></table>

I see about 15 PSI +/- in those temps, the hotter it gets the lower it goes. Does your water pressure start out good and then drop as you pick up speed or does it just stay at 6-8?

[KHill3611]

It will start out at 10-12 psi, then the next time it maybe 6 psi & the next run you make it might be 10 psi or might be 6,4,8 or 12 psi. No rime or reason to it. The other day it got up to 16 psi once.

[Neilslure]

Are you making long runs? I have engine temp on my Lowrance screen. If I take off with my motor at around 140-150 degrees (usually what it reads in the summer after fishing for a few minutes) I will have low pressure until it gets below 130, this may take a mile or two.

[KHill3611]

I have the interface cable for my yamaha to HDS also. I usely run a mile or two & while I'm running the temp is 132 deg. What is weird to me is I didn't notice my pressure dropping until this year and this the third season on this motor, it may be normal, my motor has 190 hours. My buddies that run the same motor tell me that they are running around 20 psi, but they don't have the hours that I do.