Beta 38 running hot

Kimarah · Member

Beta 38 running hot

Stanley · Guru

Hello,

How many hours on the engine?
How old is it?
Is the coolant level going down?
Can you reach full RPM in neutral?
Can you reach full RPM in gear?

The first thing to check is at what temp does the alarm go off ?
You can varify this with an infrared temp gun. The temp that the alarm goes off should be 210 degrees F.

Next I suggest that you block off the flow to the hot water heater. Just remove the hose that goes from the back of the cylinder head to the hot water heater and block it off. Then run the engine and see it anything has changed.

Let me know what you find.
Stanley

Kimarah · Member

About 1200 hours on the engine, I think it's is 10 years old, but I can check I think I have the invoice paid by the previous owner. The coolant level is not going down. I will check the rpm tomorrow. Where do you get an infrared gun? I will also try the water heater block. Does the thermostat housing have a gasket? Is that worth checking?

Kimarah · Member

In neutral 3000rpm at full throttle, in gear 2750 rpm.

Kimarah · Member

Btw I have a water temperature gauge, but I do not now how accurate it is. It is not part of the beta marine instrument pack. It shows the current temperature at 2000 rpm is 240deg. It used to run at about 180/190 deg at 2000 rpm on the gauge.

Stanley · Guru

You can get an infra red temp gun at ant auto parts supplier or look on Amazon.com. You must varify what is happening or everything is just guess work.

Kimarah · Member

Thanks, I've ordered one from Amazon, I will try this weekend. Where on the engine should I make the reading?

Stanley · Guru

At the back of the cylinder head where the fitting is for the hot water heater supply and on the neck of the thermostat housing just below the thermostst. This 2nd position is where the temp sender should be.

Kimarah · Member

The temperature at the thermostat housing and the water heat outlet was 201 degrees F running underway at 2000 RPM. The gauge shows 240 degrees F . I assume that means the gauge is bad in any case.

Running a full throttle at the dock under load the overtemp light came on when the temperature at the thermostat housing was 250 degrees. F.

Note the gauge was an aftermarket gauge purchased at West Marine and connected to the existing sensor.

Farron · Senior Member

Hello Mark,

Obviously the aftermarket gauge cannot be trusted to give proper readings and cannot be used for diagnostics. Gauges and senders must be matched to achieve proper function.

I will be happy to pursue this further but I will need more information about the operating parameters of the engine than what has currently been provided.

Please call me at your convenience to discuss this issue.

Ph: 1-252-249-2473

Brendan · Member

I have overheating problems with my beta 10 .
After overheating some gunk appeared in the heat exchanger where you top up the coolant!
When idling it will shift 6 litres of seawater/min. but when revved up this does not increase much if at all
I have checked the impeller, it's ok
I have replaced the thermostat (which was removed to see if that would help), it's ok
The sea**** and piping is clear
I removed the heat exchanger and cleaned it, it's ok. There's a separator bar across the back cap of the heat exchanger which does not have any kind of seal fitted to it, is that how it should be ?

-- Edited by Brendan on Sunday 5th of August 2012 03:43:38 AM

Kimarah · Member

Farron, I found the test certificate for the engine.

It s serial number 1W6304, test date 12/8/02, so it is just 10-years old. It further show an on-load rpm or 3,000 and off load of 3,200 rpm. Installation date is listed as 10-31-02 on the warranty card. The label in the maintenance manual also shows a reference WOC K10796.

Hopefully this will allow you to select a suitable gauge and sender.

It has a 15" prop via a sillette drive.

Farron · Senior Member

Hello Brendan,

The Beta 10 with a heat exchanger should ship 15 liters of water at 1500 rpm. I would suspect that you have a water flow issue.

If you have "gunk" in your coolant I would suggest flushing and adding new coolant.

A closed cooling system requires a thermostat to cool properly. Do not operate the engine without it.

Check that your heat exchanger presssure cap is sealing properly and that the heat exhcanger has been correctly assmebled per the operators manual.

Brendan · Member

Thanks Farron, how would I go about checking the heat exchanger cap?.

I find the horizontal divider a strange one, surely the seawater would take a shortcut through it if there's no seal rather than go through the proper channels

Farron · Senior Member

Hello Brendan,

Heat exchanger caps can be visually inspected for cracked rubber seals or be functionaly tested using a pressure tool made for this purpose.

The new style heat exchanger where the end caps are secured with three allen bolts uses a rubber seal at the divider.

The older units where the end caps are secured with a single bolt in the middle do not.