K1200RS leaks with Synthetic oil

[bludandi]

Whats the story regarding the use of full Synthetic oil compared to regular oil.
I currently use full synthetic oil in my K1200RS and have noticed a small leak.
I was told just recently that the gasket on the K1200RS doesn't support synthetic oil,and will leak.
It leaks because the molecules of the synthetic oil are significantly smaller than that of regular oil- thanks for your time, sincerely blu.

[swbell]

On a trip last spring I bought some oil from the gas station. Didn't realize it until later that I had added Synthetic. Must have pick it up by mistake. After 200miles I began to noice this: 15686

Once I did a complete oil change and back to the 20/50 didn't have a problem the rest of the season with oil seepage. We won't talk about other "issues" that happened...:whistle

[deilenberger]

Whats the story regarding the use of full Synthetic oil compared to regular oil.
I currently use full synthetic oil in my K1200RS and have noticed a small leak.
I was told just recently that the gasket on the K1200RS doesn't support synthetic oil,and will leak.
It leaks because the molecules of the synthetic oil are significantly smaller than that of regular oil- thanks for your time, sincerely blu.That's an interesting (and wrong) theory. The molecule sizes are not different.

I have heard of one verified case where going from synthetic oil to regular oil cured a leak on a BMW - so it's worth your while to try it at your next oil change.

That said - BMW certainly has seals in any bike made for the last 25 years that are capable of being used with synthetic oil. If I had to push that a bit - I'd say the past 35-40 years probably. Chances are good that switching to regular oil will not fix your leak, and you'll have to track it down and see what's actually causing it to leak.

[PGlaves]

OK - here is another case of that happening. Voni's R1100 RS was about a year old. Synthetic (Mobile 1 freshly installed before the trip - first synthetic in the bike) lube in the final drive. We took a trip from Kansas to Texas. At a rest area I discovered a couple of drops of gear oil on the rear wheel (leaned over on sidestand - gravity). I wiped it up. We proceeded. Next stop - same thing. Next stop - repeat. At the rally I decided to check the level and see how much lubricant was gone. I found it about one ounce low. I couldn't find Mobil 1 at the stopNrob in the small rally town so got Penzoil 80w90 dino oil and topped it off. Within 100 miles it stopped leaking.

At home I decided to give it the "fluke test" so drained the lubricant and installed Mobil 1 again. Within about 100 miles it started leaking. I took out the synthetic and installed dino, and again the leak stopped. I kept dino oil in the bike. I finally replaced the seal at 326,340 miles when I had it apart to check bearing health.

I had exactly the same experience with the transmission in Old Smokey - my late and lamented K75. The output shaft seal leaked with synthetic in the transmission and didn't leak with dino in the transmission. After two or three tries to test it, I just stopped even thinking about synthetic in that transmission. The seal was original and not leaking with dino in the box when the bike died at 370K miles.

Since I have been repeatedly told that this is just an "old wives tale" or an "urban legend" by the true believers of the church of the man-made molecule, I normally just let people leak whatever they want to leak out of their motorcycles. But I know that I saw what I saw.

[deilenberger]

OK - here is another case of that happening. Voni's R1100 RS was about a year old. Synthetic (Mobile 1 freshly installed before the trip - first synthetic in the bike) lube in the final drive. We took a trip from Kansas to Texas. At a rest area I discovered a couple of drops of gear oil on the rear wheel (leaned over on sidestand - gravity). I wiped it up. We proceeded. Next stop - same thing. Next stop - repeat. At the rally I decided to check the level and see how much lubricant was gone. I found it about one ounce low. I couldn't find Mobil 1 at the stopNrob in the small rally town so got Penzoil 80w90 dino oil and topped it off. Within 100 miles it stopped leaking.
Actually - that's the case I was referring to.. it's not "another" - it's the one.. :dance
At home I decided to give it the "fluke test" so drained the lubricant and installed Mobil 1 again. Within about 100 miles it started leaking. I took out the synthetic and installed dino, and again the leak stopped. I kept dino oil in the bike. I finally replaced the seal at 326,340 miles when I had it apart to check bearing health.

I had exactly the same experience with the transmission in Old Smokey - my late and lamented K75. The output shaft seal leaked with synthetic in the transmission and didn't leak with dino in the transmission. After two or three tries to test it, I just stopped even thinking about synthetic in that transmission. The seal was original and not leaking with dino in the box when the bike died at 370K miles.

Since I have been repeatedly told that this is just an "old wives tale" or an "urban legend" by the true believers of the church of the man-made molecule, I normally just let people leak whatever they want to leak out of their motorcycles. But I know that I saw what I saw.

And as I pointed out - it's a cheap experiment to see if it applies to your bike... if so - we can add "another" case.

[BuddingGeezer]

I have a buddy with a 1976 Kawasaki Z1 900 that has no leaks on conventional oil, with synthetic the cam plugs and seals leak.

Ralph Sims

[aaaaaa]

Are you really suggesting that experiences can vary? There are Gremlins which prevent oil leaking from some bikes and cause leaks on others. I saw it for myself on the TV series "Twilight Zone". Happy New Year!!!!
robert

[osbornk]

That's an interesting (and wrong) theory. The molecule sizes are not different.

I have heard of one verified case where going from synthetic oil to regular oil cured a leak on a BMW - so it's worth your while to try it at your next oil change.

That said - BMW certainly has seals in any bike made for the last 25 years that are capable of being used with synthetic oil. If I had to push that a bit - I'd say the past 35-40 years probably. Chances are good that switching to regular oil will not fix your leak, and you'll have to track it down and see what's actually causing it to leak.

I changed to synthetic on 2 BMW motorcycles and both resulted in oil leaks and seepage that stopped when I went back to conventional oil. I tried it first in a 1985 K100RT about 11 or 12 years ago. The rear seal started seeping after a moderate number of miles and it quit leaking when I changed back to conventional oil. My next adventure was with my 1986 R80RT. When I bought it, the owner had just changed it to synthetic for the first time (the carpet under the bike was dry). After I rode it a few hundred miles, the push rod tube seals started seeping and dripping onto the carpet. I changed it to conventional oil and I haven't had seepage enough to drip for the last 8 years. I didn't wait until my nex oil change on either bike because I don't like an oil mess.

Synthetic is probably OK with a late model if the seals are still soft but I'll never use it in another vehicle that has several years or miles on it.

[PGlaves]

Are you really suggesting that experiences can vary? There are Gremlins which prevent oil leaking from some bikes and cause leaks on others. I saw it for myself on the TV series "Twilight Zone". Happy New Year!!!!
robert

Conditions yes! Gremlins no!

[Colt03]

I have used Mobil 1 15-50 in my K1100LT since about 15000 miles with no problem. I did However, have and issue with synthetic Final Drive synthetic. Mobil 1 - notice a leak on the way to Trenton. kept it topped off until I got home and then put Dino 75-90 in and the leak stopped. I am not as curious as Paul, so I never repeated the Mobil 1 final drive oil, I just keep it with Dino 75-90.

1996K1100LT 140,000
2004 R1150GS 66,000