Can diesel engine oil used in 4stroke bike?

Answer 1

No Automotive Engine oil is different then 4 Stroke Motorcycle Engine Oil.

CAR VS. MOTORCYCLE OIL:
Car oils are formulated for cars. Motorcycle oils are specifically formulated for motorcycles. Motorcycles induce accelerated viscosity breakdown, and thus motorcycle oils contain additives that car oils do not to correct for this. Additionally, many car oils contain additives which are not suitable for motorcycles with wet clutches; if you have a wet clutch (or aren't sure), always stick to good motorcycle oils.

Motorcycles Engines are Special
In most motorcycle engines, those same engine surfaces generally move much faster than they do in car and truck engines, conventionally twice to ten times as fast, due to difference in RPM ranges, stroke lengths, stroke speeds (i.e. - piston speed), et cetera. Additionally, most modern street-oriented motorcycles have a "wet clutch", which means that the clutch plates also sit in the same oil that the rest of the engine uses to lubricate itself. Most also have the transmission also sharing this same oil. Throw in the fact that some motorcycles are still oil-air cooled (which causes the oil to run 1.5 to 3 times hotter than a water-cooled engine). These four differences (speed, clutch exposure, transmission exposure and oil temp) are the grounds for the basic differences between formulations of motorcycle oils and car oils.

A Motorcycle-specific Oil Standard:
The JASO MA standard was passed in 1998 specifically for motorcycle engine/tranny requirements that weren't being met by solely the API standards. As a result, if your manufacturer has specified an oil that meets JASO MA and API SF/SG/SH/SH+SJ (any of these), it is critically important that you meet BOTH of those standards and not just one or the other. If you ride a Japanese motorcycle build between 1971 and 2005, and it calls for one of the following API specs (SD, SE, SF, SG and/or SH), then the JASO MA standard is recommended (but may not be required) -- as it will help keep your older motorcycle from encountering some of the problems that induced the JASO organization to create the JASO MA standard in the first place. This is expecially true for air and oil-air cooled high-RPM motorcycles. Note that JASO MB is a competing standard specifically for a different engine type, and does not replace nor supercede the JASO MA standard. Be careful to read the specs fully, as some oils claim to "exceed the JASO-MA friction standard" without meeting all of the JASO-MA specs.
In 2008, JASO split the JASO-MA standard into two substandards: JASO-MA1 and JASO-MA2. If your needs called for JASO-MA, JASO MA1 is the follow-on standard for your bike.