First fork oil change

Had my first ride in the woods on my 08 yz450f! wow! but that deserves a separate thread...

the manual says change for oil after break in (which is for me - now)

a buddy mechanic of mine in UAE used to say they put crap fork oil to our new CRFs so we flushed and changed the fork oil first thing...

how do you guys go about it? is it an absolute must? or it can wait 10-20 hours (or when seals start leaking)? :prof:

Had my first ride in the woods on my 08 yz450f! wow! but that deserves a separate thread...

the manual says change for oil after break in (which is for me - now)

a buddy mechanic of mine in UAE used to say they put crap fork oil to our new CRFs so we flushed and changed the fork oil first thing...

how do you guys go about it? is it an absolute must? or it can wait 10-20 hours (or when seals start leaking)? :prof:

the 08 yz450, and probably the 250, come stock with a very high grade fork oil that breaks down really quick. Like your engine the forks break in, break the oil down, you will see other gunk floating in it and you will lose that plush feeling it came with. Yes its good to change the fork oil after break in, if you are riding mud, or weigh more then 180 pounds, your fork seals will probably need changing shortly anyway so you could prob wait. I weigh 200 pounds, an did a lot of mudd through December and Jan and my fork seals were toast by Feb. I got the bike early Oct. So, when they were leaking I got new seals, got stiffer springs and man what a difference those made! I also elected to go with a lower grade fork oil that isnt as plush as the stock but it holds up much much longer, I can prob wait 6 months now till my next fork oil change

Is it the same with shock oil? Should it be replaced after brake-in.

the 08 yz450...come stock with a very high grade fork oil that breaks down really quick.
Which is it? It's high grade, or breaks down quick?

The fork oil should be changed early in the bike's life because of the wear debris that builds up in them early during break in. The manual will call for Yamaha S1 fluid, which, in the US, costs about 3 times what other good fork oils do. Don't bother with it. Just use a high quality 3-7wt fork oil.

Shock oil doesn't need to be replaced as quickly because the shock is not a load bearing suspension member that has to control the location of the wheel and handle braking loads, etc., as the fork does. The swing arm takes care of that work, and the shock controls the suspension movement only.

Thank you guys and great videos too - as I done fork oil change on my WR and now will do on YZ and seem like a proper filling procedure is esssential (getting all the bubbles out).

Anyhu, what we have here is Motul synt and semi synt fork oil that comes in 5,10,15. Is it as good as the S1 oil (we have none here)? it better be good with the price Motuls carry!

Use the Motul 5 wt. It's at least as good, if not better, than the S1, and probably costs less.

while we are at it - i opened 2 cans of Motul 5s - synt and semi synt. (i guessed i should buy 5)

Former is transparent and latter - red..... I noticed btw the guy in the video puts transparent liquid into the inner cartridge and then reddish liquid into the fork leg.

Is there any differnece between synt and semi synt fluids - and it must be different takes cut into one video there - right? :prof:

Some people do use different fluids in the inner and outer portions of the fork. Some of them even have what sound like good reasons for doing this. On the '06 or later YZF, I wouldn't bother.

The synthetic will probably be a little more durable, and probably be a little more consistent at different temperatures. Either should work. You will need about 1300-1500cc of oil.

On this note ive got an 07 450 and i only take the bike into the shop after the first break in. I know they did the valves and oil do you think they also did the Fork oil?? i havent noticed any change in suspension performance or lack of.

nope - I do not feel any difference when fork oil is changed on new bikes...

But down 20 hours and couple of muddy races - yes - change oil and seals and feel the difference and joy :prof:

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