Matt's KDX 225 Alaska edition!

[Chopperpilot]

Ok, took the bike out today for it's first real ride after a few heat cycles. The Millennium Technologies 225 big bore kit is pretty awesome. I assumed the bigger bore would run a little richer than the 200, so I went one size smaller on the PJ and MJ and swapped in a CEK needle in place of the Airstriker's DEK needle. I'm not sure if I magically hit the tune button on the head, or just how awesome the MT BBK is, but WOW!
The bike is an explosion of throttle response at any point any where. Not 100% sure on the complete tune yet because I haven't actually held it WOT in gear yet..... because um... well it's really really fast! No bog, no hesitation, no where. Well, actually if you're 2 gears above where you should be and whack the throttle, it'll give a little pause. I ended up riding a gear higher than optimal just to help me control engine response.

Now the 2003 YZ250 front end.... Pretty good. I lucked out and these already had Gold Valves in them. These are 46mm USD KYBs that have a 'not sought after at all' 32mm cartridge in them that MXers did not care for. The 2003 version was the last year Yamaha tried the 32mm mid-valve set up (it's terrible because it has to flow a ton of fluid through it), and these had about 2.5mm of float in the mid-valve from the factory. I think these with the softer base valving with Gold Valves, work pretty great for trail use compared to last years 93 model KX 43 USDs (which I had slightly softened the valving and really liked them compared to the factory KDX front fork). I feel like the front end is even more planted, stable, and steerable than the 93 KX setup. Hitting rocks, roots, or ruts and I feel I was getting less deflection than last year. So I guess the bigger 46mm forks and the significantly stiffer axle mounting setup (compared to the 93 KX) makes a difference. I'm using the same tire and KX wheel as last year so that hasn't changed. The YZ triple trees have a solid cast handle bar mount which probably also helps out with the preciseness feeling. I didn't feel the solid mount was too rough or vibraty.... but this is only one ride.

I also Gold Valved and rebuilt the rear shock ..... and what can I say....... it feels like a shock! I'm shockingly sensitive to forks on motorcycles and mountain bikes (I re-valve my mountain bike forks too!) and apparently I'm shockingly insensitive to rear suspension on both (as long as they don't rebound too fast!). I do think the rear has better traction and feels more stable, but I'm also dealing with a whole 'nuther level of engine power now and can't really feel particulars about the rear end. I think I might also have put a little too much preload on the rear and I'm sorting that out now.
I also put a LED front light on and it works fine with the stock lighting circuit, seems to be very bright..... but in Alaska, dirtbike season correlates with not ever needing a light season so I don't know how well it lights up the trail. I am having a slight issue with the throttle/cable. I ran the throttle cable back in a was that was relaxed and can move freely, but the bike will slightly rev up with a full turn to the right and a couple of times it seemed like it wanted to hang the revs a little. Can I just lube the throttle cable? new PWK return spring? new throttle cable? (I'd probably do the KX throttle if I did that)

[Chopperpilot]

Ok, put a few more rides on the 225BBK and the revamped suspension. Here's the take away. Still blown away by the motor, it makes it easier to ride trails faster. Which brings me to the other take away. The suspension is much more planted (front and rear) than ever before. I'm having to continue to adjust clickers because I'm riding faster and faster over rough roots and rocks on single track. I found I had to slow the rebound on the forks a little bit and on the rear shock too.
I remember the factory front end (and the previous 93KX front end) both getting 'easy to induce' headshake above about 53mph. No change with the YZ 46mm forks. Is this what other people notice too? It doesn't 'have' headshake, but hitting a frost heave on the road at 53 and above, gets the forks going a little wiggly fairly easily. I have the forks up in the triple trees about 10mm (probably..... it's a line on the tubes I lined up) so I might try dropping them and see how that works. No complaints with how tight it will turn! one of the reasons I'm cutting through the trails much faster.

[KDXGarage]

Thanks for the updates. I am glad it is working out for you.