Suzuki DT65 cooling issue

[Kreso]

Hi guys,
I have a 1997 suzuki DT65. I am trying to figure out how the water cooling system works. I have removed the exhaust cover plate and cleaned it from salt. However, there is a round hole in the lower part that seems to be blocked (or it is just a dead space?). See the attached images, marked with arrow. Does anybody know what is the purpose of this hole? Where does the water that is pumped by the water pump enter the power head and exhaust plate? And can the water go to the cylinder block before passing through exhaust plate? Thanks

 

[tommarvin]

Can you clean the hole out, if not it looks like a locating hole. Is there a threaded hole there for the exhaust cover plate,don't see it.

Overheating is three things, install new impeller, put the thermostat in a pan of cold water slowly heat it up what temp does it open, or a bad sensor, test it.

I would get a service manual, and parts catalog. Put it back together, torque it correct, get new seals,gaskets,anti seize on all bolts.

 

[tommarvin]

Get an awl and see if you can clear out the hole, I don't see a threaded hole for a bolt on exhaust manifold there, did you snap off a bolt there.

overheat is three things,water pump which is a hard rubber impeller on an outboard, thermostat stuck shut, test is a pan of hot water, or bad sensor.

 

[Kreso]

Hi tommarvin,
I have cleaned the hole as much as I could, about 2.5 inches deep but can't see inside as it is below the rim of the engine lover cover squirting. It doesn't seem like a locating hole, as it is not possible to put the exhaust cover in the opposite way. This hole goes all the way from engine block through exhaust cover and exhaust cover plate. I think it is important for the water flow but can't figure out how the water comes to the exhaust plate/cover. I have a service manual, but it does not tell anything about the hole. Water pump was replaced, it works OK, there is water from the pee hole. Thermostat is OK, but I broke the sensor while trying to get it out and will have to get a new one.

 

[tommarvin]

Were going to test our overheat sensor heating up a pan of water slowly, with the end of the sensor in the warming water, 180 F we should hear the buzzer.

I don't know how the water gets to the exhaust plate/cover . All I know is when the t-stat opens,water flows from the top of head down to the bottom.

Lets take a step back, Why do you think you have a cooling problem ? You said the water pump and t-stat are ok, do you have a bad sensor ?

 

[Kreso]

The engine runs OK while out of water. As soon as I put the boat in water and push the trottle to higher rpms the engine dies. I have never heard an alarm sound, though. When I removed the exhaust manifold/ jacket cover, the water passages were blocked by salt. I have cleaned them but can't reinstall before I take out the two bolts that broke.

The sensor might have been bad but it broke during removal - it was stuck by salt deposits and the plastic housing broke.

I tried to pour water inside the engine water cooling passages through the thermostat opening, water sensor opening and the hole down in the exhaust cooling system. It didn't flow out through the intake holes on the gearcase, but flowed out from the pee hole, propeller and hole on the front side of the lower unit. I would expect to see the water coming out of the intake holes. Am I wrong? I would like to know how the cooling system works even if the cleaning and sensor replacement solves the problem.

 

[Nikola4501]

Hello,

My name name is Nicolas and I live in France. (Sorry for my English).

I write you because i have the same problem on my suzuki DT 65.

The round hole in the lower part is blocked. (see my photo)

Have you solved this problem?

Thanks.

 

[Nikola4501]

Hello,

I'm very happy today...The hole was unblocked with a long drill bit.

The pipes adjoin with the cooling system!