YAMAHOP

[GMC]

i think i gotta get me a yammy my 480 rears running a 9.8 kg spring and i recon that may be a lil soft

I just thought you’d had it lowered

[motomaniac]

[quote author=Nathan S link=topic=14053.msg140470#msg140470 date=127906957

Late model valve pistons have to be a good thing, but will take some work in getting the valving right (or take it to someone who knows what they're doing).

The other thing to watch for is a worn shock body. The valve piston wears the inside of the body around ride height, and then the oil can get past the valving and screw up the dampening.


[/quote]

Nathan s point about the shock body is the first thing to check.They are untreated shit alum. and if its worn like Nathan said then you'll be wasting your time. Firkos ride on the low hour bike would suggest that the shock on that bike isn't worn out yet.

[head]

I am running a late model Yamaha piston, with modern valving. I run two springs a Racetech 4.2 and a cut down spring which started life as a 250J spring. Had to machine extra grooves in body of shock. I had trouble getting the right race and static sag combo. But after much trial and error this is what worked for me. I am 70kg thought. It is hard to fit a decent valving stack as there is not enough length on shaft to fit. Standard valving is very primitive with not many shims. All the effort is worth it though, the rear end on my bike works very well. The bike is a YZ250H. Have a look at the racetech website in the vintage section, under the YZ465 project. Similar to my setup.

[TonyB]

Hi Rosvickicambel can you get more details on the workd performance shock? i went on the website but could not find monoshocks for the vintage bikes they had other vintsage but not a big monoshock. Now if i use my setup and the body is worn slightly ( from memory it isnt) but could I get it anodised or something to bring it back to spec? or what?

[ted]

Tony..Give Nick or Brad a call at Teknik Racing 02 47322626

They did my 465,,,new spring, Ohlins piston etc....Very happy

[TonyB]

I'm erring towards renovating the original shock body possibly hard anodising it, fitting a G3 gold valve , and triple rate springs from works performance, i recon that should be the best i can do. It might however be more expensive this way than buying a whole new shock By the way how do Ohlins pistons and Gold valvs pistons differ? do they work differently. I like the look of the gold valve as it has nice large ports and looks like the oil will flow easilly on sharp quick square edges.

[ted]

Just spoke to Nick...ohlins piston, hard anodised, new progressive spring etc....all in stock  $ 850...3 week turnaround ( due to anodising ) with 12 month warranty

My 2 yz`s have these mods and not a problem

Your call