synthetic oil??

[Johnboy]

91 gs500e with 20k mi. Is it better to use synthetic oil versus regular motor oil? i just had all my valves replaced because the last owner burned them up not using good oil. will synthetic oil make the valves last longer? if so, what is a good kind to use?

[The Buddha]

Valves burned from not using good oil... OK sounds a little fishy to me... but go ahead and use synthetic just in case....
Cool.
Srinath.

[octane]

DO a search on the forum. THis topic has been covered before to mixed opinions. I gotta disagree with Srinath on this one, due to my own experiences. Long story short: Synthetic good for engine, bad for clutch with 20,000 miles.

[Stephen072774]

I just switched to the Castrol syn. blend.  Seems to be the best of both worlds :dunno:

[Rema1000]

Valves burned from not using good oil... OK sounds a little fishy to me...

Agreed.  The GS mill did just fine for a decade before synthetic oils.  if the valves themselves were "bad", there had to be some other problem.  Like the PO ran with high compression pistons and didn't cut the reliefs enough or something.  I'd be suspicious about that.

If by "burned valves" you mean burned cam lobes, then yes, that could have happened if the PO let them go without adjusting too long.  Maybe the cam shafts were replaced.

[mp183]

Mine is getting close to 18,000 miles.  All on Castrol GTX 10-40.  Runs like new.  Valves adjusted twice.  Over 50 mpg at all speeds including commuting to Manhattan.

[Johnboy]

ok, so synthetic oil doesnt make much of a difference. is there a specific type of oil for bikes? Castrol GTX 10-40 is car oil isnt it? does it matter if you use car oil versus bike oil if there is a special kind for bikes?

[Rema1000]

Synth oil probably does make some difference, especially if you're racing.  In my mind, if you check your oil frequently, and change it at regular intervals and also before and after storage, then you're doing 90% of the good you can do.  You can do the same with synthetic motorcycle-specific oil, and get that last 10% of good.  But 99.9% of GSes will die for reasons other than oil breakdown.  So chances are that you will never recoup the expense.  That said, I may switch to synth this year once the temps drop below freezing.  The GS makes all sorts of funny noises if you start it at 20F and you're still running 20-50 oil .

Many people run automotive oil without problems.  The only thing to watch-out for is that oils marked "Energy Conserving" may have additives which can cause the clutch to slip.  Often there are oils on the shelf (even at WalMart) for old trucks, or for racing, which lack some of the modern additives.  WalMart's "Accel" or "Tech2000" (both <$1/quart) fall into this category.  Many of the "racing" oils are 20-50, since nobody races much in the dead of winter; 20-50 works fine for me.

There are also some motorcycle-specific oils, and even motorcycle-specific synthetic oils, which are supposed to resist breakdown of lubricity even under the extra stress of the wet clutch and hot engine.  However, if you're not racing, I don't see the GS as being a terribly harsh environment.

[The Buddha]

JohnBoy... your sig says...

You know the U.S. is going crazy when the best rapper is a white guy, the best golfer is a black guy, the tallest basketball player is chinese, and the three most powerful men in America are named 'Bush', duck', and 'Colon'.

I have heard this before ... but the most powerful in america was Bush, duck, John and Colon...  Lovely, first time I heard it... I split my sides laughing, spit my coffee into the windshield and crashed my F-150 into the nearest herd of bikers...  :lol: ... OK OK just kidding, but I was in my car at the time and the radio dude was a lousy joke teller, but still...
Cool.
Srinath.

[indestructibleman]

don't forget that the French are accusing the U.S. of arrogance and the Germans are cautioning against war.

[Johnboy]

yeah, i tried to put that in also, but it wouldnt fit. i liked it.  :lol: