03 suzuki df70 temp light when trimmed up.

[Pgoss8]

I took the boat out last weekend and on my way back to the dock it quit pumping water out of the tell tale. got it home put a new impeller and lower plate and gasket on it today and it still isn't pumping water. On the muffs, water gets all the way up to the pee hole and comes out but it's only the pressure of the hose I have attached which caused the temp light to come on. I took the lower unit back off put the hose on the pickup that goes from the pump into the engine and water came out of the pee hole no problem. Had water flowing both directions to the engine and back but the pump will not pump water up to the motor itself. what could be causing this? Was thinking thermostats, but I should still be getting pressure out of the tell tale because it is before them right?

[Harper]

As I understand it, the thermostat controls engine temps at low RPMs. When underway at higher RPMs, the water pressure valve provides a bypass of the stat, and permits full flow of water through the engine to cool it. Make sure that neither the stat nor the water valve are crudded up and that they are working freely. I would advise that you check all the cooling apparatus and also look into the cooling passages as much as possible to see if it looks like there is any buildup of salts or other deposits indicating possible clogging of smaller cooling passages.

[Pgoss8]

I just came back in, rechecked the impeller, it's in right. Keyway is in correct. Removed every hose and connection I could find. Flowed water and wire through every orifice and hole I could find. Everything flowed fine. Put my hose on the pickup tube in the midsection where the pump slides on, got water all the way to the top of the engine where the thermostat is. Everything seems clear and freeflowing. Everything is pointing to the pump not pumping.... I even verified it is the correct impeller. I'm lost! Where is the valve you speak of?

[Harper]

The valve is near the thermostat. http://www.boats.net/parts/search/Su...TAT/parts.html Are you sure that the vanes on your impeller are bent in the correct direction?

[Pgoss8]

Ah that part.... I removed it yesterday and tried running the motor without it, still nothing. And I double checked the pump vanes when I reinstalled the impeller the 2nd time.

[Hoosmatroos]

Is the water intake free of debris?

[Pgoss8]

Yes I remove and clean that too I'm going to take her to the water this afternoon and see if it being in the water makes a difference

[Pgoss8]

Well I got the no pumping issue fixed. I had the new gasket between the pump plate and housing, not below the plate where it belongs. This caused space between the pump and plate which in turn kept it from pumping. And I think I may be onto something with the overheat issue.... ran the boat by a guy that has sold and serviced cobias for 20+ years. Right away he looked at my transom and asked if I was getting any overheat alarms.... I said I was and how did he know? He said the depth of my transducer for the depth/fish finder was to deep and probably causing water flow problems/ cavitation for the water pickups on the lower unit. Kinda makes sense since when trimmed all the way down it's fine but the minute I trim up and change the angle it sets the alarm off..... time to test it with the transducer off and see what happens!

[Hoosmatroos]

Good catch. Great that the pumping issue is solved. And that's why it's hard to give good advice when you can't see what's going on. Cavitation is a possibility due to a low mounting spot but also when the transducer is leaning to much to the back instead of almost horizontal. Do you have a picture?

And yes, testing with the transducer off is the best way to know.

[Moonlighter]

Well I got the no pumping issue fixed. I had the new gasket between the pump plate and housing, not below the plate where it belongs. This caused space between the pump and plate which in turn kept it from pumping. And I think I may be onto something with the overheat issue.... ran the boat by a guy that has sold and serviced cobias for 20+ years. Right away he looked at my transom and asked if I was getting any overheat alarms.... I said I was and how did he know? He said the depth of my transducer for the depth/fish finder was to deep and probably causing water flow problems/ cavitation for the water pickups on the lower unit. Kinda makes sense since when trimmed all the way down it's fine but the minute I trim up and change the angle it sets the alarm off..... time to test it with the transducer off and see what happens!

Ok great that you have the water pump issue sorted.

It sounds like the transducer must be very poorly positioned if its creating flow problems for the engine! Most transducer installation guides make it very clear to locate them at least a few inches outside the prop diameter for this reason.

If you can post some pics of the transom showing the transducer we may be able to suggest better location/height.

What model transducr is it?

[Pgoss8]

Only picture I have right now 20180221_073149.png

[Hoosmatroos]

That one is to small for my eyes

[Moonlighter]

That one is to small for my eyes

Mine too. But from what I can see, its far too close into the keel, and looks too deep as well.

Here is a link to an installation guide from Airmar, who are the biggest manufacturer of transducers around. You will see that it shows how far away from the prop radius to mount it. And depth.

https://www.gemeco.com/custom/docs/P66Install.pdf

Most transducers of the type you have will have a moulding line around the middle, and this is a good guide as to the depth they should be mounted. Use a straight edge under the hull and line up the mould line, that is a good starting point for depth. Tilt the trailing edge down very slightly.

[Pgoss8]

I should have the boat back tomorrow. I will remove the transducer and test it out this weekend.

[Pgoss8]

Well, that was the problem! Moved the transducer and it runs great!