Low water press help

[KakaroT]

Hey guys I have a new rig I just got last week and I have a pair of 350 vrods in it with 6 inch setback jackplates, am running them at prop shaft length and as soon as I trim just a little bit I get low water press alarm I tried plugging holes on the side I plugged 5 already and same problem what do u guys redolent to fix this problem I can't lower the engines anymore they are all the way down on the holes and jackplates are down also

[cherokee_chief]

What's the actual pressure reading. 8-15 is all u need. The alarms are stupid.

[KakaroT]

It's around 9-10 but when I trim drops to 7

[cherokee_chief]

Even 7 is fine. Unplug the sensor and be done with it. Keep and eye one the guage and u won't have to worry

[KakaroT]

Can I keep plugging holes or should I put the metal plates on the sides of the water intakes

[cherokee_chief]

I wouldn't plug to many
Atleast leave 3 on each side. No lwp?

[KakaroT]

I had 3 unplugged and was getting air, I plugged them all and opened up a little the lwpu holes and now I have good good pressure now my other problem is am at 69 mph at 5K 5200rpm with 26p bravo 1 what prop do u guys recommend me ? This 350s should be at 6400 rpm I was told

[Brad Zastrow]

7 psi is not fine!!! Do not override the sensors. Unless you like paying for rebuilds. Can you install a nose cone?

[KakaroT]

I plugged all the holes and drilled the one in the low water pick up and now I have good water press 12-17 psi

[stormbringer1]

Maybe I'll take some flack for this but I have a different take on it. While I agree the factory settings and alarms might be a little on the cautious side BUT they are there to keep the average guy safe and when running at high RPM with a Merc there just is not a lot of margin for error when the alarms go off. Most of us yank the thermostats and put a 3/8 washer in the thermostat pan and rout a water hose down from both heads and when racing I never wanted to see less than 15 lbs of pressure preferably 20-30. You need temp guages on both heads to make the decision about removing the alarms. While those gearcases look great I am not so familiar with the 300s but wonder why they are not under the gearcase pickups? I always used Bob's nose cones with the dual water hose option and it paid off. If you don't have that option or don't want to replace the gearcases than I think.....maybe Lavorsi makes a hull mounted water pickup that you can adjust so as not to over drag the bottom and produce all the water pressure you can stand. Requires some plumbing but might be the safest option for you that and a good synthetic oil like Amsoil for extra protection. Hope thats a help.