Hi, I browsed this forum before making my current purchase of a 2006 X model with 17000ks on it, and as I have further questions I thought I should sign up.

I was wondering how I can tell if there are any mods on it. The previous owner added some fog lights and a custom seat, so it's possible he tinkered with the internals. What would I look for?
(I have no mechanical knowledge, so simple words and descriptions please.)

If the sprockets are changed up or down, does that throw off the speedo/odo?
What's the easiest way to tell if the speed indicated has been corrected or has the 10% error (*without* getting a fine or loss of licence)?
If the speedo has been corrected, would my odo be off?

My riding terrain is the hilly back-roads of mullum-lismore-murwullimbah, etc.
My previous bike was a drz400, on which I averaged 23km/l, and I was told to expect better efficiency from a fuel injection bike even with the bigger engine.
However, my first two fill-ups averaged out to a 19km/l consumption.
It's probably because I was used to the higher-revving drz and was staying in 3rd too long, and taking some of the sharper corners in 2nd. I hardly used the 5th gear at all (except for that bit where I get to see how fast I can go before I run out of straight road - 157 *indicated* so far).

However, I tried using higher gears and lower revs through curves and today I got 24/l.
Is that good or can I do better?

What are the average workable speed ranges for the gears for this model (assuming no mods)?
eg, is 3rd okay to pull from 40km,
is 4th lugging if it pulls from 70km?

I'm a bit worried about lugging the engine, and I kind of do like being in a gear that will respond to input immediately coming out of the corner so I can punch through it. In a higher gear there is always a bit of delay before the engine really accelerates and it sometimes feels 'spongy'.
However in a lower gear there is the problem of the bike being a little twitchy as the engine-breaking/acceleration fight it out. I can use the clutch to smooth that out a bit, but it's a bad habit I'm told.


There is quite a bit of popping going on whenever I back off the throttle - does this mean I'm wasting a lot of fuel and is it because the settings are richer or that it may have been modded? Or is it an EFI thing?
It seems loud, is that normal for this model? I don't want to be obnoxious, I like a bit of noise but not too much. If I could get rid of the popping I would feel less self conscious. The dealer replaced the baffles, so it's not that.

There apparently is a way to change the fuel/air mixture via the dashboard - is that worth tinkering with?
What's the basic principle?
eg, more fuel = ? vs. more air = ?
And how does this differ from the fuel mods that are available?
Is there a mod for better fuel efficiency, or just more power?

Is flash-lube still a good thing to be using when I fill up?

Apart from oil, chain lube and tyres, do I need to be concerned about anything else? I just want it to go as long as it can without specialist intervention.
I used to change oil every 1500 on the drz, is 3000 or 5000 the interval for the xt?

It's a bit buzzy and vibey, but I am used to that with the drz. The vibes are just a bit *thumpier* this time.

I am enjoying my arse off with it, it's a step-up in terms of bike skill as I can take corners faster and with more lean than I could the drz.
It's noticeably more sensitive to bumps and so on in those corners though.
I've only been riding a couple years and am still on P's.
I'm thinking of doing an advanced learners course to keep myself earthed, as it makes me feel more risky and feel like I'm better than I am.