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jams229

'07 WR450 Fork Oil Spec - S1?

10 posts in this topic

I have searched and searched but can not find the answer to my question:

I am changing the fork oil this weekend in my 2007 WR450, and the manual calls for Yamaha S1 fork oil. But they don't tell you what weight it is!

I know I don't have to use the Yamaha "suspension fluid" but I would like to know what weight it is in case I want to go up on the weight...

Thanks.

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S1 is typically 5wt. I've always used belray 5wt fork oil. I put Race Tech gold valves in my older WR and Race Tech says to put 5wt in it.

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The viscosity of Yamaha Suspension oils is not usually listed because it's really not a very big issue. The damping in modern suspension units is set up to operate on pressure differentials within the unit, and these are not dependent to any great degree on viscosity. This is why your suspension works so consistently from dead cold through until the end of the day. The difference is fluid viscosity from 60 degrees F to 140 is often 3-4 times the difference between a 5wt and a 10wt fluid.

The one place within a fork that viscosity really matters is in the hydraulic bottoming cones, which work more as a variable orifice, and less as a pressure control valve.

Almost any good fork fluid will serve to replace S1 at a far lower price, and Amsoil Shock Therapy is among the best. There is another fluid that is even better, but as far as I know is not yet ready for general retail sales: http://www.smartperformanceinc.com/215VM2K5.html

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I would go with a high quality fork oil - not the yamaha brand - been there done that. Go with a racing brand. I used Maxima and there are many good ones. I also use more fluid than stock calls for so I dont bottom out on the big jumps or OOPSES! I go with 30cc's over. Good luck Jason

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I'm trying to find some specs for the 215VM2K5 oil, all I can find are ride reports, does anyone know what the Kinematic Viscosity at 40 & 100c are, and hence the viscosity index, does it carry any international standards? The reports are very encouraging but I'm worried that it's use may invalidate my warranty, with Yamaha being so insistent on the use of JASO spec oils.

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I'm trying to find some specs for the 215VM2K5 oil, all I can find are ride reports, does anyone know what the Kinematic Viscosity at 40 & 100c are, and hence the viscosity index, does it carry any international standards? The reports are very encouraging but I'm worried that it's use may invalidate my warranty, with Yamaha being so insistent on the use of JASO spec oils.
Ordinary viscosity measurements don't have the same applicability to 215.VM2.K5 as with conventional fluids. Read:

http://www.thumpertalk.com/forum/showthread.php?p=6411550#post6411550

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