I have the BD 1005 28 hp. The engine has been running hot, but not overheating, so I had a mechanic clean the heat exchanger out. When I ran the boat this weekend under normal conditions it overheated. I still have good raw water flow and the impeller is in good condition. Could an air lock in the closed cooling system (circulation to the hot water heater) cause this? If so what is the easiest way to tell and the easiest way to fix it?
Please answer the following before I can really give you any advice. 1) What do you mean by running hot? What temp is the engine running at? 2) When you are in gear can you reach 3,600 RPM when motoring? 3) Is there a hot water heater connected to the engines cooling system? If yes to #3 please answer the following; a) is the hot water heater at the same level as the engine or above the engine or below? b) did you use the Beta Marine fittings to connect your hot water heater or did you use some others?
1. By running hot, the engine was operating at 2,800 rpms at a temp of 200 to 205+ F. I have had this engine for a number of years and it typically operates around 190 to 195F at 2,800. The last time it began running at 200 to 205 (a couple of years ago) I had the heat exchanger cleaned and everything returned to normal. After the heat exchanger was cleaned this time the engine temp was fine at idle but motoring at 2,800 the temp went to 220-230+ before I shut it down.
2. The engine can reach 3,600 rpm in gear but I do not normally operate the engine at this rpm.
3. There is a hot water heater connected to the engines cooling system.
3a. The hot water heater is located above the engine.
3b. The hot water heater is connected to the engine with all beta marine fittings.
I think that your problem stems from the hot water heater being above the engine. When it is above the engine it is very difficult to fill the cooling system completely and you tend to get an air lock which will cause the engine to run hot.
The cure is actually very simple. I suggest that you fit a separate coolant pressure tank (with a pressure cap) above the level of the engine and hot water heater and plumb it into the 5/8" hose that goes from the fitting at the bottom of the heat exchanger tank to the hot water heater. As long as there are no large loops in the hose, you will be able to fill and check the coolant from the top pressure cap.
Please let me know how you get on. regards, Stanley
Stanley, I have a Beta Marine BV 1505 engine ( engine #5G3827, Woc K16007) with 35 hrs on the engine. While running at 2200 rpm, the temperature was stabilized at 195-200 deg F. The engine had been running for 30 min at 2200 rpm. I have a 100 amp generator with a cooling fan that was running. The load on the generator was low since the batteries were nearly fully charged (alternator output 14.2v). The dedicated engine sea **** is a 0.5 in sea ****. Is this the normal operating temperature or do I need to install a 0.75 sea **** for the engine?
-- Edited by terrybryan on Sunday 23rd of August 2009 03:44:12 PM
-- Edited by terrybryan on Sunday 23rd of August 2009 03:48:31 PM