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Discussion Starter #1 (Edited)
Believing the hype, last fall I bought and added your $45 gallon of SAE 10W-40 Synthetic Motorcycle Oil. Within two weeks, I noticed a difference....cam tensioners started making noise, shifting became clunkier (is that a word?) and the coffee grinder sound returned.
After less than 1000 miles I drained it yesterday and returned to Rotella T Synthetic ($21 gal). In less than 20 miles, the coffee grinder sound is gone, shifts smoother, and no more tensioner noise.

Care to comment??
 

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I can believe that. I used Lucus Syn-blend MC oil in a little 250 cruiser I had and that had to be the worst stuff I've come across ever. But I did go back to the Castol GTX 20-50 MC synthetic, which I think is good oil, pricy but good. Rotella T 15W-40 dino is what I'm using in the 750 now, and I like it very much. Any big performance difference between the Rotella T dino and synthetic?
 

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With the hope of not starting an oil thread, I won't answer the question on "synthetic verses regular" but will offer my theory on the OPs observation.

Over the years here I have read many posts in many oil threads where someone says they switched to oil "B" after using oil "A" and thought the stuff was crap, pointing out various symptoms they had not before. The odd thing I noticed was there were some that reported that they used oil B ....without issues , but their bike didn't like oil A when they tried it.

I been using Rottela T (organic) oil for years and am pretty happy with it, but again have read the a few that switched to it had the same issues VoIP reported. Odd to say the least.

My only theory, and yes just a theory, is that when you drain your oil you really don't get all of it. This means the new oil will mix with some of the old. Oil is not just oil, it has "additives". These differ from maker to maker. My thinking here is some of these additives do not mix well with additives used by other makers. Much like "drug interaction" Shells additive package (that's what the oil guys call it) reacts badly when mixed with Lucas oils additive package...(for example here)

This would explain why those that jump to another oil and have issues with it.... when those that have been using that oil for years think it's awesome.

I have noticed that those using "specialty oils".. Like Lucas, Amsoil, seem to have the most difficulty in switching to another brand.... It almost seems like these smaller companies formulate their oil to react badly on purpose.....
 

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The oil thread has already been started, so... I have had the best luck with non synthetic name brand 20w50 oil, though before the price doubled, I did use Mobil 1 motorcycle specific 20w50 with no problems. Around locally, I tend to use SuperTech 20w50, and change it every 1000 miles. I used Lucas 50w racing oil in my race car for 3 years, and never had an internal engine failure after hundreds of runs. The engine slowly wore, but nothing broke. I still think the main thing about motorcycle oil is weight, rather than brand or type. I use only 20w50, whether it is regular, synthetic, car oil, or motorcycle specific. I won't use Rotella in a motorcycle, not because it is not good oil, but because it does not come in 20w50.

I have found Castro Actevo Xtra 20w50 motorcycle specific oil to work beautifully in the Vulcan 750. It's expensive at $35 a gallon, but I have no problem leaving it in for 3000 miles. I believe it to be way better than the more expensive Amsoil stuff, though I have never actually used Amsoil. Even if it's good oil, it is certainly not the only good oil, and I don't like the sleazy way it is usually sold, OR all the hype that goes with it, which I believe is completely undeserved.
 

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Dave
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Well,
I just changed from Amsoil 20w50 to Amsoil 10w40. I had the 20w50 in for 2 years since I only ride about 1M-1500 recreational miles only, no interstates. I bought the bike two years ago and put the 20w50 in it right away.

Took it for the first ride yesterday and it shifts much easier and neutral is easy to find on the move now. The clutch didn't do that grabbing thing when I start out either. Had that the whole time I have own it until warmed up good.

Since the ride was only about 8 miles I'll need to see if the engine starts to make more noise with the 10w40.
 

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With the hope of not starting an oil thread
Isn't winter over yet? ;)
 

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Well,
I just changed from Amsoil 20w50 to Amsoil 10w40. I had the 20w50 in for 2 years since I only ride about 1M-1500 recreational miles only, no interstates. I bought the bike two years ago and put the 20w50 in it right away.

Took it for the first ride yesterday and it shifts much easier and neutral is easy to find on the move now. The clutch didn't do that grabbing thing when I start out either. Had that the whole time I have own it until warmed up good.

Since the ride was only about 8 miles I'll need to see if the engine starts to make more noise with the 10w40.

I have found in the few instances where I have tried it in motorcycles that 10w40 causes much notchier shifting than 20w50 after the engine has warmed up. Here in AZ, 20w40 has the consistency of ATF (which is 10w hydraulic oil) when it is hot, And 10w40 would have to be even thinner. Another reason I use 20w50 is it has more load bearing ability and shear strength, which means it protects bearings and gears better. Transmission gears really should use a 80-90w gear oil. They would last longer and shift easier. That type of oil would not be good for a wet clutch though. Shifting problems are probably caused by fluid drag on the clutch. Wet clutches all have this problem, and the heavier the oil, the more drag they will have.


This is another area where motorcycles could use car technology to their advantage. Engine oil in the engine, gear oil in the transmission, and a dry clutch. Along with tubeless tires and a load based charging system.
 
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