Castrol R4 5W-40, good oil?

[mxtester]

This is my first post to this informative forum.

I have a 250cc four-stroke single motocross bike that revs to about 13,500 RPM. The manual recommends Castrol R4 superbike 5W-40 oil. When I purchased this oil, the guy said that there are no detergents in the oil. So he said as long as I change it often, it should be good. I have no problem changing the oil often, as it is only 1.3L.

Any idea what is the advantange of no detergents if that is true?

Also, is there a much of a power increase with 5W-40 over 10W-40? Does it help throttle response?

Thanks for the help.

 

[Propflux01]

The 'Guy' is totally wrong. R4 is a synthetic oil meeting JASO MA standards. Hardly a 'non-detergent' oil. And Yes, at 13500RPM, less viscous friction is attained using a 5w based oil over a 10w based oil. here is a link to the product.

http://www.castrolusa.com/products/productpageo.asp?product_id=32&product_category=5

 

[beanoil]

[ October 19, 2004, 01:38 AM: Message edited by: beanoil ]

 

[beanoil]

I agree that the "Guy" is wrong. I'm figuring you have either an RMZ or a KXF? Castrol Superbike R4 is a good oil, but I think there are others that may be better. I have excellent luck with Mobil MX4T, 10-40. So good in fact, that at 24 hours of run time, during practice laps, the drain plug came out of the bike somewhere on the track. I had forgotten to safety wire it, and the new thumpers loosen EVERY dang bolt on the bike. I discovered the missing plug while prepping the bike for the first moto, and was shocked to see the sight glass empty. The bike hadn't missed a beat during practice, but there was no trail of oil anywhere near the pits, or in the line taken from the track to the pits. I put a spare drain plug in, and refilled with a little over a liter of oil. I ran both motos that day, and a full practice session the following Thursday. The 30 hour inspection revealed no change in valve clearance, and the cams were perfect, with no galling, or hot spots. The filter did have some junk in it, but upon close inspection, it was clutch material and not metal. I redid the top end at 43 hours, and the cylinder still had the factory crosshatch, ring end gap was still in spec, and the cams were still fine, as well as the cam chain. The lesson is that the drain plug should have been wired, and I am really glad I had a synthetic on board. I change the Mobil 1 every 4 hours, and clean the filter (Scott's Stainless Steel) each time. But my Mobil 1 days are numbered, as Motorex is sponsoring me for '05. I am certain that their PowerSynt 4T will be very good also, based on using their products in my old two stroke, years ago.
I have also used Redline 10-40 in a Katana, and in two stroke gearboxes before with no clutch issues and excellent wear measurements. It is also a fine oil, even if their 2 cycle Racing Oil isn't!

 

[Motorbike]

quote:

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Originally posted by mxtester:

Also, is there a much of a power increase with 5W-40 over 10W-40? Does it help throttle response?

Thanks for the help.

---

Thats a very light 13.0 cSt oil but hey , thats the trend with synlubes these days . Noack of that oil is very very good saying probable good base oils used . You can buy it online for 100 bucks a case...shipped


If in doubt , use the Maxima 10w-40 . It is a 13.0 cSt oil also and is loaded up with anti-wear and is an Ester oil with PAO . Good deals on this one too if you know a Parts Unlimited dealer . Buy it in the gallon jugs for more savings .

 

[Mackelroy]

I've ran the R4,

It's an excellent engine oil, and cleans as well as the best out there.

I was concerned the lighter weight wouldn't hold up as well, but it did.

The issue with offroad bikes, you got to dump the oil so often it just destroys what ever you run, then cost factor comes into play.

The 5w40 Rotella is probably the best for the buck in that situation as far as a synthetic if you got to dump frequently.IMHO