What Oil for Beta Tug JD3

[Doug the Tug]

Having recently acquired a new Beta JD3 engine, I now have to look after it. The documents suggest 15W/40, but also say API CG-4 or CF-4, the letters G and F seem a little higher than I expected for an engine design such as the JD3.

 

The manual also says "Straight mineral oils are not suitable, neither are oils of less detergency than specified." Which if my understanding of oil specification is correct, would suggest that an API of say CF is not suitable.

 

What do other owners of JD3's use?

[churchward]

Although slow revving the JD3 is a fairly new design of engine. an API CF-4 spec oil was published before API CF (only by 4 years) so CF is the later spec.

 

A 15W 40 API CF oil will be fine for the JD3 (a very common spec of diesel oil) If you will use the engine in winter and expect it to start in very cold conditions a 10W 40 API CF may give better cold start protection.

 

API CF spec was designed for engines running on higher sulphur content fuel which does suite the red diesel we use in our boats.

 

see the following chart for some insight to the API specs of oil.

 

http://www.calsci.com/motorcycleinfo/API.html

Edited July 9, 2010 by churchward