2005 YZ250 Set up and tuning

steve125

LIFETIME SPONSOR
Oct 19, 2000
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Ive had 2 rides on the fork updates on the 05 YZ 250.

Before,, std. springs,, 240cc oil outer chamber,,C at 7 out and R at 10 out.

Now,, 1 up on the fork spring rate, 255cc oil,, C at 14 out and R at 12 out. For sand track C 10-12 out and R 12 out.

The stiffer spring rate and higher oil level has allowed me to bring the clickers out into a plusher range.
forks work better on all bumps than before and have a firmer mid to end of the travel feel,, with no bottoming, but using all the travel.

Im real happy with this set-up. :cool:
 

bbqtex

Member
Mar 23, 2005
9
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Bikedude127, just crank out a little on the shock spring to lower the back a hair. That should help with the head shake.Turn it out 1/2 turn and go ride it. If it still shakes turn it out another 1/2 ect.
Remember that we all have different weights and riding positions bar postions , some ride towards the front of the seat more than others, this also affects handling. The exact measurements from the book dont work perfect for everybody, I agree with the others that the rebound is too quick.
Remeber also that what works on one terrain/track may not be ideal at another.
I'm no expert but hope this helps. It works for me.

Vctory lap, I bought mine used from a friend. He rode it several weeks and the harsh rough ride never went away, his weight is very close to yours. He's a very fast intermmediate.
He had it revalved and sprung for his weight and liked it much better. I ride mostly offroad and am riding it with his valving and springs. I wound up at c 20@ out and r @8 out forks; same on shock. The bike would not turn well and i raised the forks 12 mm in the clamps and added a little more sag, it turned better and the headshake went away. The ride was much plusher where he originally had it set at c 14 out and r @ 10 out forks and the same on shock. I only weigh 154lbs so it felt like a railroad car to me. It still is not perfect or as good as my ktm setup but the springs are not right. I may not change them as i just got the bike and need to ride it longer to decide if I like it enought to keep it.
 
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Victorylap

Member
Sep 3, 2004
7
0
Hey Great feedback thanks a lot guys.

Once fully broken in I got my set up pretty close. I had just kep adding oil and messing with the clickers. I dont remember where it is set now but I have it all taken apart... long story. Leaky fork seal leads to, hole in radiator leads to, untightend hose clamp, to totaly melted down motor during a race. Now its time for me to do a bit more than the usual maintenece.

Lemons
"I have also found some cases where the inner chambers were not
bled properly."
"Worst come to worst add the spacer to give the fork some preload.
Then use 220cc of of 7.5weight fluid in the outer chamber only and you
should see feel a better fork"

What is the recomended procedure for bleeding the inner chambers. The last bike I had with twin chambers was an 01 CR 250. Is it the same for the Kayabas or are there any special tricks?
I will definatly try the spacers! Thanks a lot for the tip, I just too cheap to go out and buy springs right now.
220 cc seems like a good starting point but I think I may need to add a bit more. I believe i have added 5 cc's about 8 times to bring me to my current setting.

Steve, it sounds like you have really done some great testing. I really apreciate you feedback. You had mentioned you re-valved you shock. What did you change in the stack? I rade a friends bike a week ago whose bike had been set up by I-moto they do MX Tech suspension. I must say it was very good. The shock was amazing. But the forks were still a bit stiff unlesss you were really charging.
 

yzfourstroke

Member
Jul 11, 2002
3
0
Just got my 05 yz250 suspension back from Enzo. Had them do the full deal, here are the specs...
175lbs w/o gear.

Forks - One step stiffer on front springs .45 and 1.8 pressure spring. 320cc oil (setup for subtanks). 10 clicks out on comp/rebound.

Shock - Stock spring - 4.9 - 150psi gas pressure, 8 clicks out Rebound, 10 clicks out LS compression, 1 1/2 out on HS compression - recommended sag 105mm

I have not ridden bike yet, so we will see how it works out...
 

steve125

LIFETIME SPONSOR
Oct 19, 2000
1,252
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I look forward to reading your Enzo ride report, do you just ride offroad or MX??


That said i've updated my 250 suspension from my previous comments. My at home up-grades really worked well over stock, but in the end I still had issues.

First I had Pete of HDR/MX-Tech do the front forks. We went back to the std springs, pre-loaded the ICS spring and main springs, revalved the mid and replaced the base valves. Set the oil at 255cc and clickers at 12c 10r.

Now the forks feel like a good set of Showas, ride higher, plusher, and have superb bottoming resistance. The forks were installed to 7mm up in the clamps for a great combo of turning and stability. 12mm up if you want RM like turning :nod:

Now since the forks feel better than the shock, it was time to update that. Pete pulled the shock apart and installed a MX-Tech valve along with the proper shims from my weight and riding ability. We went 1 up on the shock spring from std. Set sag at 104mm C15 HSC 1 1/2 R12.

The shock was a real suprise, so cushy but no bottoming that I could feel. It hooked up well, tracked perfect, rebound was light but not springy and very controlled. All the small-mid bumps were gone. Thats a huge improvement over stock! I have not touched a clicker in 2 rides. We should all be so lucky HUH??

An A+ job from Pete and MX-Tech!!!
 
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