Iknow Yamaha always trys to push 10w30 or 20w40 because these are the weights that they sell....is there any conceivable reason that i shouldnt run honda GN4 10w40 in my raptor. I know it is a good oil and the honda dealer is very close.

 

Living here on the east coast, with crazy temp fluctuations most of us with 4-strokes including my 01 Rap run the Mobil 1 15/50 synthetic, it flows great in cold weather and is durable for X-treme heat..plus with Rap's having a dry-sump type oiling system it helps on start-up, Not to mention the asic's (the oils ability to "cling and climb&quot is excellent especially for gear boxes.

 

Your Honda oil is just fine. If you actually ran the Mobil 1 in your Raptor go buy a new clutch and do a complete engine flush. By now your old clutch is done.

 

Yeahiplan to run thepetrol based GN4 Honda oil for a few changes to ensure proper break in and then switch to a semi synthetic if not full synthetic.Rap720 I am curious asto why youthink the raptor clutch would dislike Mobil1? I have used Mobil1 in many many sportbikes... mylatest bike is a GSXR1000 which made 144.9 HP on the dyno and never abit of slippage....many R1s,GSXRs,CBRs,etc and no trouble. I have noticed that the raptor has a buttery smooth clutch pull which seems to point to soft clutch springs though..

 

I agree on the clutch feel even with the heavy springs. BUT with the springs, at 70+hp, there are no problems.

ON the oil issue, it seems that the synthetic and any oil with added friction modifiers, the clutch tends to slip or burn very easily. I suspect that the oil does it's job too well. I have heard that Mobil actually makes an oil specifically for wet clutch applications but that it costs about $8 per quart. I personally have no problem using the factory Yamaha oil and I change it at the end of any hard day of riding. It is too easy.

On the hp and slip issue you mentioned, I suspect that your 140+hp street bike is geared substantially different from the 660 (or at least the 01 660). My point is that the 660, probably has more torque load on the clutch than your street bike even with the hp difference. The reason is simply in the gearing. I also suspect that your 140hp street bike either has more clutches, clutches of a larger diameter and/or heavier springs.

Just my .02.

 

General rule is to stay away from spreads over 20 in the multi visco oils.
Not many manufacturers are recommending 10w-40 anymore. I would stay with 10w-30 or 20w-40. Doesn't have to be Yamaha brand. Motorcycle only oils are preferred. Stay away from the anti friction agents. Automobile synthetics in ATVs/motorcycles with wet clutches is also a bad idea.

 

I assume this rule does not apply to synthetics? ( Re: Yamalube 10w50 synthetic)

 

I use 10w-30 anybrand. It will be a year in just three weeks and I haven't had a single problem.........................

 

Not to fire up any argument but I need to defend my previous post... My R1 and My Raptor (purchased together 11/00 although I did'nt take delivery of the R1 till later)) were both broken in on the factory supplied oil (Yamawhatever) and immediatly got Mobil 1, And my last six of my vin are 006144 (early)and I have never experienced any trans failure, clutch failure, or any failures of the gearbox what-so-ever(and I ride every weekend sometimes sat & sun with shee's so you know I'm hammering it; every ATV, Micro-Sprint, Motorcycle(street&dirt)I have ever had to change oil in always got Mobil 1 and I have NEVER seen a smoked clutch pack yet from the use of that oil.As a matter of fact GM and Ford BOTH are testing running that oil in new auto trans...I know they're not bikes...but still operate using clutch, steel, clutch, steel,at way higher temps than we could dream of. As for the Visc. jump from 15 to 50....it's synthetic...the chances of your organic 10/30 failing are wayyy higher. Before anyone flies off the deep end on me...I recomend running whatever you think, feel, or know works for you.

 

I am not gonna go off on anyone. Just sharing what I have read, heard, and what makes since in MY little mind. I have also used Mobile 1 in my Vmax until I read the reports from the scientist with the thick glasses. I didn't have any problems but, no reason to take any chances. So, I'll stick with 10w-30 or 20w-40 dinosaur motorcycle only. Change the oil at proper intervals and that is one less thing I have to worry about. The span between the numbers does apply to synthetics. Unfortunately, that is a over simplified answer. To read all about it go to: http://people.ne.mediaone.net/cburian/mc/oil/oils2.txt
Like you said, everyone run what you feel comfortable running.
My intention was just to answer the original posters question about running 10w40 in his Raptor. The answer, I would not recommend running 10w40 in anything. Oil em up and let's ride.[img]i/expressions/face-icon-small-smile.gif[/img]