over heating issue

[hooked on Grady]

So I got the boat in and when running at wot it began to over heat. Beyond the temp coming up it felt like i was dragging an anchor. So cruising at 3600 rpm or so it seems fine except terribly slow at about 15 mph. When I was back in my slip at idle the warning sound went off again. Both times I was getting water flow. Could I have a bad thermostat?
back to performance, it definitely does not run as it should at wot. I would think I should at least get 23 or 24 knots. That being said I put 2 Garmin transducers and a panoptic transducer pretty much on the center line as much as possible. Now I have read that may not be a good idea because it could be causing bad water in front of prop. i have a 225 optimax with a 17 inch pitch not sure of diameter, I will mostly be running full fuel tanks and 4 guys plus cooler, gear and 2 anchors. any thoughts/

 

[seasick]

First things first: When you had this issue, was this the first outing since you added the transducers?

You may have created too much water disturbance and cavitation. That could explain the slow speed and the over heating. The placement of the transducers on the center line could be be the cause, especially the Panoptix . What did the installation instructions advise?

 

[hooked on Grady]

as close to the center line as possible but I didn't realize that meant out of the way of the prop. this is my first boat with a bracket drive. i thought with the engine back i would be fine. Not so much. I have wide trim tabs on the back so I'm hoping i will have room to move them, I have ordered to new mounts so i do not have to disturb the holes i just made. I know they are watertight. thank you for your time.

 

[hooked on Grady]

from above, it was my first outing period. new boat for me

 

[wrxhoon]

From what you say the Ducers could effect it but also the engine maybe mounted higher than it should be . Have you tried playing around with the trim?
Is it the same when trimmed in all the way?
What happens if you turn hard ? Does the prop cavitate?
The 17" prop should be OK without bottom paint.
As a guide I had a Seafarer 228 ( probably around the same weight as your offshore ) with 25 Optimax , I had a 17" Enertia prop and was Ideal .
Overheating could be a separate issue ( water pump) but if the pump sucks air will effect it . If you have smartcraft gauges check water pressure.

 

[ScottyCee]

A simple test would be to pull your transducers and try running it again. The 3600 RPM / slow hull speed is worrisome. or do you have any friends that are old hands at boating? Someone should be able to tell if your prop is cavitating to the extent that it would have to be to create that big of a performance decrement.

 

[Sparkdog118]

There should be at least 8 inches to the right or left for clearance for the prop not to cavitate when mounting a transducer. Try testing the boat with the transducer tipped up out of the water to see if that is the problem before you start drilling more holes.

 

[seasick]

A simple test would be to pull your transducers and try running it again. The 3600 RPM / slow hull speed is worrisome. or do you have any friends that are old hands at boating? Someone should be able to tell if your prop is cavitating to the extent that it would have to be to create that big of a performance decrement.

I agree with this idea. You want to get the ducers out of the way and go for a test run to see how the boat handles. You may be dealing with more than one issue. The first item to resolve is the low speed at high revs. If that reoccurs with the ducers out of the way, find out why and fix it. You may not need to relocate the ducer mounts.

 

[hooked on Grady]

first, thanks to all who replied. the first thing is definitely getting them unmounted and tied back out of the way to test run. I was planning on trying this first in the next day or so. As far as any hard turns, no I have not mainly because I still getting a feel for it and hadn't thought about those moves as part of figuring this out yet. also I did just block sand the bottom then epoxy primed and 2 coats of micron csc bottom paint if that would affect prop selection it was not bottom painted before. thanks again everyone!

 

[ScottyCee]

it felt like i was dragging an anchor

Bottom paint might make a subtle difference, but certainly is not responsible for what you see right now. Try it with the ducers out of the way. It may sound totally different - which might be just what you want. It sounds to me like you may just be burning a hole in the water... (sucking air into the prop zone the whole time)

 

[seasick]

Bottom paint might make a subtle difference, but certainly is not responsible for what you see right now. Try it with the ducers out of the way. It may sound totally different - which might be just what you want. It sounds to me like you may just be burning a hole in the water... (sucking air into the prop zone the whole time)

I think so too. It would explain both symptoms. I am just not so confident that the transducers are causing the disruption of water flow. I guess we should know soon.

 

[ScottyCee]

I've seen people completely puzzled as to why they aren't getting a boat on a plane - start and stop, start and stop. Turns out they have the motor at the bottom of the TILT range, but the very top of TRIM range. There is much to learn if you haven't spent time around these beasts...