GStwin.com GS500 Message Forum

Main Area => General GS500 Discussion => Topic started by: SirHansford on August 12, 2016, 03:53:48 AM

Title: Engine Oil
Post by: SirHansford on August 12, 2016, 03:53:48 AM
"Disclaimer :  I am not a mechanic by any stretch of the imagination"                                                                                                                                                             Hi all!   I recently bought a 2007 GS500 and while the oil looked good upon purchase, i decided to go ahead and change the oil.   I am not sure what type the previous owner put in it,  but i went back with Mobile 1 10-40 synthetic motoorcycle oil.  Oddly,  after filling up the crank case and starting the motor,  i noticed that it idles 100-200 rpms lower. It was 1200-1400 and now it's generally 1100-1300.  Appears to be this case after a few cool downs/start ups.   Is this normal when switching from a mineral based oil to a synthetic?  If he had a heavier oil in it and i went with 10-40,  could that have done it?  Is this even an issue i should be concerned with?  Thanks for any of your input!  New member and i really dig the information and support from this site!
Title: Re: Engine Oil
Post by: HPP8140 on August 12, 2016, 12:39:49 PM
Weather the same? I'm in the East coast and it has gotten hot & muggy. Notice the same symptoms. Normal less dense air.
Title: Re: Engine Oil
Post by: gregjet on August 12, 2016, 01:30:38 PM
Make sure you haven't overfilled the cases. Measure the oil level with the bike level ( fore/aft AND side to side). Too much oil will drag as the cranks hiy it and lower the idle RPM.
Title: Re: Engine Oil
Post by: Janx101 on August 12, 2016, 01:55:48 PM
Ummm. . I'm entirely prepared to be wrong.   But isn't Mobil 1 seething with friction modifiers? .. it's not JASO rated either?! ...

Friction modified oil is a BAD IDEA in a wet clutch situation. . Nearly all bikes use a wet clutch!
Title: Re: Engine Oil
Post by: gsJack on August 12, 2016, 06:56:27 PM
Quote from: Janx101 on August 12, 2016, 01:55:48 PM
Ummm. . I'm entirely prepared to be wrong.   But isn't Mobil 1 seething with friction modifiers? .. it's not JASO rated either?! ...

Friction modified oil is a BAD IDEA in a wet clutch situation. . Nearly all bikes use a wet clutch!

The only thing wrong with Mobile 1 10-40 synthetic motorcycle oil is that it's kinda pricey for a GS500.  Never saw a 10w-40 oil that wasn't suitable for a GS, the energy conserving oils are lower viscosity ones like 10w-30, 5w-20, etc that are marked with this donut symbol, don't use with wet clutch:

(http://beta.motorist.org/uploads/publishing/large/oil2.jpg)

I like the 15W-40 heavy duty oils like Shell Rotella T, Mobil Delvac, etc for the GS.

Title: Re: Engine Oil
Post by: Rallyfan on August 12, 2016, 07:05:35 PM
Sometimes Delvac is cheaper than Rotella so that's tempting.
Title: Re: Engine Oil
Post by: Janx101 on August 12, 2016, 11:10:26 PM
I use valvoline 15w40 diesel oil anyway. . Which is jaso rated :)