Some ZX9 Basics

[Rabbitt5000]

Howdy all. My 1997 ZX9 has a hesitation just above idle. Any ideas about the cause and how to rectify it?

Also wondering about the basics of setting the suspension up for my weight (76kg) and tyre pressures.

Any other advice to a newby would be appreciated.

Thanks

[Strika]

ZX9R B3's had carbies. Hence, it sounds like a Jetting or needle height issue more than anything else. Has it got the standard pipe or an aftermarket one??? Other solutions could be carburettor synchronisation, Plugs or even leads. My best guess though would be carbs. Best fix is to not ride it just off idle!!!

As for suspension, start by setting the rider sag. Measure the distance, from a static point-ie;from a point on the ducktail to the axle at the rear......the front should be self explanatory....if it's not, then i'd suggest enlisting someone more knowledgeable to assist you), with the suspension completely unweighted/unloaded. Hop on the bike and then measure from the same points. Aim for around 30mm front and rear difference. From there, it's about fiddling with the damping till it's right. If it has standard suspension, then it's pretty much next to useless. I would crank the damping to max on both the front and rear. Even then, it's gonna wallow still. If you really want to fix it, replace the rear shock and have the forks resprung and revalved.

As for Tyre pressures....this is a piss take isn't it!!!! You'll get loads of opinions and lots of people will tell you different, but the B's are a heavy unit and as such, I would run between 32-36 Psi in the front and 38-42 in the rear, depending on the brand of tyre.

Good luck with the 9!

[mick_dundee]

Suspension guide for a ZX9 written by Rossi available here http://www.ksrc-au.com/index.php?itemid=21

[Rabbitt5000]

Thanks for the help so far. I have been looking at pics on the net and noticed that the bike looks like the 1998 variants rather than the 1997. Checked the rego papers and they say a ZX900C. Checked the net and the VIN appears to be from the "C" series too. The rego papers say 1997 model though - although it was registered in December. Seems I should be asking about the "C". Geez being new can make you a bit dopey!

Does this make any difference to your suggestions?

It does have an after market pipe (well at least a muffler). Its a D & D Carbon unit. Sounds nice, but is it causing problems? Loved the solution not to ride it just off idle - maybe when I get the hang of things a bit! It sounds perfect at idle and revs very cleanly once passed the hesitation.

I am enjoying this learning experience. Thanks for your patience and help.

[ty]

The suggestions still all apply I think.
The C model is lighter than the B, but still fairly heavy - also still carby.

The pipe won't cause 'problems', but may need some slight carb mods (rejetting). Normally that's only really necessary on a full system.

I had a full akra system on my C2 model, and it wallowed a little just after idle. Just rev it a bit more when taking off and enjoy

[oldmate]

It may be a small bit of shite in the pilot jet. i had a similar problem with my six. I put some carby cleaner through the system,that helped a little but the fix in the end was to strip and clean the carbs