OX66 250 motors overheating / water spraying out of motors

[typhoon411]

All my Grady White marlin 28 with twin ox66 250's is having an issue. When on plane at 5100-5300 RPMs my starboard engine will temp out and the alarms come on. The possess have a steady stream however I noticed at the doc that there is water coming out up underneath the motor. See the following video:

http://youtu.be/EeCo1KGRtDw

I'm wondering if I blew a seal in the lower end somewhere... Thoughts? I had the water pumps all redone this season..

Thanks in advance!
Joe

Checkout my Grady rebuild page at Facebook.com/fvirishrover

 

[jbrinch88]

Re: OX66 250 motors overheating / water spraying out of moto

All my Grady White marlin 28 with twin ox66 250's is having an issue. When on plane at 5100-5300 RPMs my starboard engine will temp out and the alarms come on. The possess have a steady stream however I noticed at the doc that there is water coming out up underneath the motor. See the following video:

http://youtu.be/EeCo1KGRtDw

I'm wondering if I blew a seal in the lower end somewhere... Thoughts? I had the water pumps all redone this season..

Thanks in advance!
Joe

Checkout my Grady rebuild page at Facebook.com/fvirishrover

Overheating at high RPM is usually caused by a bad water pump. I've seen plenty of "new" pumps go bad right away due to a defective impeller separating from its hub. It may be fine at idle and low rpm, but once you are on plane the hub spins freely on the driveshaft no longer spinning the impeller.

I googled your other issue since im not too familiar with that motor, and it seems it may be a bad pressure relief (poppet) valve. Seems to cause excessive exhaust bubbling if it's not working properly by letting water escape through the mid section and not make it to the top of the engine.

I would remove your cowling and run the engine to see where the water is coming from.

 

[seasick]

Re: OX66 250 motors overheating / water spraying out of moto

All my Grady White marlin 28 with twin ox66 250's is having an issue. When on plane at 5100-5300 RPMs my starboard engine will temp out and the alarms come on. The possess have a steady stream however I noticed at the doc that there is water coming out up underneath the motor. See the following video:

http://youtu.be/EeCo1KGRtDw

I'm wondering if I blew a seal in the lower end somewhere... Thoughts? I had the water pumps all redone this season..

Thanks in advance!
Joe

Checkout my Grady rebuild page at Facebook.com/fvirishrover

It's hard to diagnose looking at the video alone but it it is probably not a poppet issue. Bad poppets affect temp at low RPMs not high ones.
You didn't say if this has been an issue since the pumps were changed or if worked OK and all of a sudden the overheating started.
The water out of the cowling is a sign that there is a leak somewhere in the water feed or that the water pump housings are leaking into the mid section. The seals could be bad or the water tube is not installed correctly. The only way to tell is to drop the LUs and see what is going on. If both motors have the same issue, I would suspect that the previous maintenance was not done correctly