Bad Oil

[Nubian]

I am beginning to strongly suspect the Mobil1 20w-50 for all my recent ills, Intermittent starter clutch problems, and now slipping clutch. Crazy Steve did point me in that direction but others here are using the same oil with no problems. Now i'm not so sure. It claims to have high performance additives

[James England]

I wouldn't use fully synthetic oil at all, myself. Or even semi-synthetic. No doubt someone will have a different view but my logic is that the bikes were designed to run on the oils available at that time...


I use 100% mineral oil from Castrol. It has low/few additives and is just a plain old mineral 20/50. I always used Castrol GTX in the 1980's.

I don't get any clutch slip and it doesn't get burnt or do anything strange. It doesn't get the white emulsified slime either. I change it every 2,000 miles (I always have on my bikes)

[crazy steve]

That 20w50 should be OK; I've seen problems when owners have used lighter viscosities like 10w40 or 15w50. But Mobil1 is different from regular dino oil (it will leak out easier that dino oil, don't ask me why), so changing the oil to a non-synthetic may help. Every bike is different, so what works in one may not work in another...

If your starter clutch is marginal, the extra 'slipperyness' of the synthetic may be enough to make it not work.

[Nubian]

That 20w50 should be OK; I've seen problems when owners have used lighter viscosities like 10w40 or 15w50. But Mobil1 is different from regular dino oil (it will leak out easier that dino oil, don't ask me why), so changing the oil to a non-synthetic may help. Every bike is different, so what works in one may not work in another...

If your starter clutch is marginal, the extra 'slipperyness' of the synthetic may be enough to make it not work.

I called my service center and they used 10w40 synthetic Yam oil for the 1st oil change since I had the bike. I had since put over 1K miles on it with no problems. I change filter and oil and it seems like within a week my starter clutch starts acting up and a couple of hundred miles after that my clutch starts slipping.
Unless they did not really use syn oil for the change. But that's another story.

[ccogswel]

Well from my experience with full synthetic oil was the same on my bike. When I first got it it ran fine with regular oil. The Starting clutch and the Clutch worked fine. But when I went to full synthetic I had clutch slippage. Went back to regular oil and has been fine since.

[James England]

The Castrol I posted a pic of is made specifically for classic bikes. They produce a whoe range of oils, right back to vintage bikes with leather oil seals etc.

The 20/50 smells completely different from modern oil. As I said, I always used to use Castrol GTX. I thought that, still being on sale and called the same, that it would be the same oil. It isn't! I spoke to Castrol and they said modern GTX very different to the oil of the same name in the 80's. Apparently, that's why they produce the Classic oil... to cater for older bikes.

[Nubian]

Well from my experience with full synthetic oil was the same on my bike. When I first got it it ran fine with regular oil. The Starting clutch and the Clutch worked fine. But when I went to full synthetic I had clutch slippage. Went back to regular oil and has been fine since.

How soon after the oil change did you start experiencing difficulties?

[natemoen]

It seems that if you experiencing trouble with the clutch when you use synthetic it is can be solved by switching to new friction disc that have ONLY had synthetic. That is the expensive fix though, way cheaper to just stick with dino oil...

[BA80]

'nuff said.

[Nubian]

'nuff said.

What weight is that?

[latexeses]

CatatonicBug has a couple of pics of the back of and oil container that shows what to look out for and avoid as far as additives go.

Bout a third of the way down the page.

http://www.xs11.com/forum/showthread.php?t=28524

[BA80]

What weight is that?

That's just a pic of the bottle, it shows no vicosity value. I use 20w50 but it's available in other weights also.

Castrol 4T Motocycle oil

[g15usmc]

if ur running full synthetic i do not suggest switching directly to the non-synthetic...unless you plan to do an entire rebuild that is...i would switch to a semi-synthetic and then move to the non-synthetic on the next oil change...Also i use yamalube 20-50...it seems to smooth out the shifting a bit...and with the age, i think it would be best to shorten times/distance between changes...

[Nubian]

if ur running full synthetic i do not suggest switching directly to the non-synthetic...unless you plan to do an entire rebuild that is...i would switch to a semi-synthetic and then move to the non-synthetic on the next oil change...Also i use yamalube 20-50...it seems to smooth out the shifting a bit...and with the age, i think it would be best to shorten times/distance between changes...

Well , I went from dino to full syn. Could that be the cause?

[WMarshy]

if ur running full synthetic i do not suggest switching directly to the non-synthetic...unless you plan to do an entire rebuild that is...i would switch to a semi-synthetic and then move to the non-synthetic on the next oil change...

What basis do you have for this suggestion? I cant see any harm in switching directly back to regular...