[Plumpton]

My “new to me” 2004 zr7 came with a YSS MZ506-320TR rear shock.

I’m not the lightest of guys but quickly realised the back end was too firm so started meddling with the settings of the shock. I’ve wound down the preload around 10 turns which has helped but would like to know if anyone has the setup guide for this shock. I emailed YSS to see if they would send me a pdf but have had no reply what so ever.

Any guidance would be appreciated.

Thanks in advance...

 

[TWOQUIDKEV]

Hi Plumton, I'm confused as to why your bike has the wrong shock fitted by the previous owner.

The YSS shock MZ506-320TR according to their website is not designed for the ZR7, it's for the the following:

Honda VFR1200/800
Kawasaki GPZ1000/900
Kawasaki ZZR1100
Suzuki GSF1200/1250
Suzuki GSXR1100
Yamaha FZ1
Yamaha FZ8

the model they quote is "KAWASAKI ZR 7 S '99-'04 MZ456-320TR-07-X" as on the link below:
https://yss.co.th/yss-europe.php

So it looks as though the previous owner has bought a shock on ebay and made it fit to save money perhaps. Now I'm no suspension guru but I would imagine that each shock is completely different hence the different part numbers, could be ride height, rebound damping or just physical dimensions of the shock.

You may be lucky and be able to adjust the suspension to suit your needs, so you could try setting up the staic sag as in this guide

https://www.visordown.com/features/guides/how-set-your-bikes-suspension

Hope that helps

 

[Plumpton]

That’ll explain why it feels wrong when riding. Whilst the 320 side of things is right. That’s the length, the spring rate and damping could be a long way off.

Might as well sell that shock on eBay as it’s in really good condition and buy the correct original item. I’m not a fast rider so won’t reach the limits of the oem shock.

Thank you vert much for this information.

 

[DaddyFlip]

There shouldn't be anything wrong with the shock you have. The only difference between the 506 and 456 series shocks is the piston size; 50mm vs. 45mm. There are some bikes in that application chart where both shocks are spec'd; here's just one of many examples:

KAWASAKI Z 750 `07-`11 MZ506-330TR-19-X
KAWASAKI Z 750 `07-`11 MZ456-330TR-19-X

It could be that the spring is too stiff, but I would rather have too stiff than too soft. Since these are OE replacement style shocks, it would be a long shot that someone put on an over-stiff spring. Let me ask this... what is the condition of the "new to you" tires? Unless you've already put new tires on the bike, check the DOT date code on the side and see what year the tires are. If they are older than 5-6 years, a set of new tires could significantly soften the ride. Outside of that, I would back the preload all the way out, see what happens, then start working on the suspension setup guide. Remember, you "ride the spring, not the preload".

Edit: You could also stiffen up the front forks with the PVC mod to balance things out a little better.

 

[Obo]

You could also stiffen up the front forks with the PVC mod to balance things out a little better.

I did this originally on the cheap, and while this was fine I ended up buying the adjustable caps off Ebay. They only ran me about $25 Cdn.

 

[DaddyFlip]

I did this originally on the cheap, and while this was fine I ended up buying the adjustable caps off Ebay. They only ran me about $25 Cdn.

I also did this originally on the cheap, and while this was fine I ended up buying the full house front end with Gold Valve Emulators from RaceTech. They only ran me about $1000 Usd.