300x water pressure issue

Ok I had my sutphen out yuesterday with twin 300x's on it, I was running the boat conseravtivly (unusual for me) as I had some new boaters on board. after they got used to it and were Ok with that speed I started to crank it up and around 5000 RPM i got a alarm and gardian kicked in, backed off the throttles and tried again. Same issue.

Checked alt belt cause its been an issue once before it was fine, flipped through the smart craft and its got .4 psi water press on starbord. Its pissing like crazy though and the port is a little weaker, Water temp is 111 on port 116 on starbord occasionally rising to 118 while port rises to 114 or so

At cruise speed 3500 RPM or so I have 13.5 on port and 3.5 on starbord and its dropping the closer I get to the dock.
As I pull into the dock My port engine isnt pissing. So I figre well the smart crafts are swapped.

Get it home pull the lowers water pumps are perfect condition. Only issue I found was the seal on the shaft above the Water pump houseing was raised about 1 inch.

I wanted to swap the senders but am not sure where the pressure senders are located on the 300x?

Thanks for any input guys.

Fired it on the hose today no water pressure no water out of either engine. Wtf. These things always run like a top now Im chasing my tailLolIm gonna drag it to the water after work tomorrow cause I have low water pickups on the hull maybe thats messing with it though Ive run it on the hose before???

You probably have a bad water pressure sensor which is telling the ecu there is no pressure sending it in to guardian mode.

If you run the boat in salt water the small line that feed the sender will clog... I have even had them clog in freshwater engines, any small piece of debris will cause this

Shaun

thanks Guys I will check the sender line,

When I pulled the lowers I did have a few grains of sand in the WP, housing I dont normally see that in there, it was VERY minimal though, I do run in the salt alot but that particular day I was running the CT river.
Ill try blowing out the line.

I already swapped the senders so it it changes from one SC gauge to another I know its the sender, Im not sure why its not pumping on the freakin hose Im 1hr away from the water so thats a little tough.

I think Ive run my 300x s on the hose before unless iM just thinking of my 200 mercs from my last boat the 300x;s have been so reliable I just dont have to touch them normally,

found the issue it was a line running into the boat for the mechanical gauge that was T'd into the smart craft gauge, the previous owner had the SC line which was 5/32 and the inside line which was 1/8 fused together and it was leaking between the hull and the cowling. Obviously reducing the pressure. simple stupid problem cost me 5hrs towing and working on the boat.LOL