XT600 faux-rally(e) (disturbing content)

[mtothef]

Okay, since this project is slowly but draining me of time and money and sanity, I figured the least i could do is put it up here for the world to laugh at. What will follow is my attempt to take what was a perfectly fine old beater of an XT600 and turn it into a fully realized exercise in futility.

Or, as a wise friend best put it - "Why are you gonna waste all that time on a perfectly happy old XT? Just ride it and save up for a KTM..."

Ahh yes. Why indeed?

Well, for starters, this whole thing has at its roots another bike: I own an Aprilia RXV550. Aside from being sound evidence that I lack common sense, the Aprilia also has proven to be a fine, if scary, bike. And, it's totally worthless to ride on pavement, at least in any sort of sane manner. Snatchy, grabby, wheelie happy, 1st too tall, 5th too short, power slides on knobbies out of corners, headers glowing red at night, crazy grin, cops don't like me, sucks fuel like a 747 on takeoff, and a reputation for occassionally barfing oil all over the place.

So, I bought a beater to get around on. A scabby 1990 XT600E Yamaha. Fortunately, I have no pictures. Suffice to say it had been hit repeatedly with the ugly stick, but it was cheap.

But then, my fundamental genetic weakness for 1980's Yamahas began to flare up. Somehow a wrecked SRX-6 ended up in the yard, and I began to think. Great. So, thanks to the genetic weakness and a well documented lack of common sense, I began to look around for parts to make the SRX live again, as well as maybe tart up the ugly XT, which was being referred to as "the scab" by my friends.

That something came about from one of the inmates here, motomind. And this bike:

[nfranco]

this will end well

[mtothef]

Realizing that somewhere toward the end of the 80s Yamaha died a thousand deaths in terms of quality, I saw in motomind's 1989 bike a plethora of possibility. Alloy swingarm, GOLD alloy rims (oooh...), a frame that looked as if the welds were made from something other than toothpaste covered in silver paint, a GIGANTIC and very hard to find spare gas tank from a first generation Tenere, a donor motor for the SRX with the later, mo bettah, crank cases and head mounting that were better suited to things like bigger pistons and higher compression, a whole slew of spare parts, and that sweet red and white style that i'm a sucker for.

So, the collection grew again, and Dumb Idea Number One struck.

I swapped the e-start motor from The Scab into the new (to me) rolling chassis. Also swapped over the wiring harness, since the e-start motor is a 12v system and the older bike was a 6v. And had to do some grim backwoods machine work to make the countershaft sprocket on the new engine lineup with the rear sprocket. And had to get some oil lines made. But basically emerged from that particular mess intact. It took a weekend, and fortunately, since I was doing the swap outside, in February, it didn't rain.

The new bike was kinda fun - the XT600e motor's primary gearing is super high, so it had trouble pulling much more than 65 into a headwind in 5th, but it got killer gas mileage, handled pretty good on the street and was totally completely utterly horrific in the dirt. my bmw r65/100 hybrid was a better dirt bike (did i mention my tragic weakness for bikes that make no sense?). But I had a sweet beater - slow, no brakes, fun. Should've been happy, right?

Wrong. Faced with a long winter, and an inability to leave well enough alone, I began researching things online, just for the helluvit. Suffice to say, the internet is a dangerous place. About as soon as I found out that a kawasaki kx500 uses EXACTY the same bearings as the old XT, an entire front end for a 91 KX showed up on ebay, for about the same amount that I'd managed to unload The Scab's rolling chassis to a similarly afflicted victim of Yamaha Thumper Collection Syndrome. Oh well, money in, money out. and phase two begins:

[mtothef]

did you know?:

that modern YZ rear ends can be found - swingarm, wheels, brakes, shocks, links, the whole kit and caboodle - in HORDES on ebay? why? what are people doing with the rest of the bikes?

this may not end as well as you think (bummer about that 19" rear wheel...):

[mtothef]

Kawasaki KX500 forks, from the anodized blue wonder years, are about 2 inches longer in total length than XT600 forks were in 1989. They've also got about two inches more travel. and about a half inch less offset.

KX500 steerer is about an inch longer, and has a step in it that won't allow the bearing to slide down enough to fit the XT headstock. Fortunately, the XT steerer presses right in. Unfortunately, it's steel, and not the ultra-sano machined aluminum that the KX one is. Oh well. Also, the damn forks are tapered, so there isn't a whole lot of wiggle room to pay around with sliding the things up and down in the triples. The combo of XT and KXX parts ends up with the forks ultimately almost the full two inches longer between axle and fork crown than before.

Stock XT head angle was 27.5 degrees. add two inches and guesstimate that it'll get about a degree and a half to two degrees slacker. Gonna have to jack the rear up at least the same amount, maybe more, to achieve a desired 27 degree even steven. Hmmm, 330 pound bike with a 38" seat height...

Gonna have to weld some steerer stops in place or else it'll have trials bike turning radius as well as triple clamp dents in the tank.

An XT600e motor wedged into an older chassis ends up with a bike that weighs 330 pounds with a half tank of gas - 54.8% over the rear, 45.2% on the front. Seems kinda rear heavy/front light. Maybe 7 gallons of gas way up high and forward will even things out. Or maybe the fact that the Tenere tank forces the rider back about 4-5 more inches will make it worse.

XT600 Tenere gas tanks fit alright at the front end, but need a little love to get done right at the back:

[mtothef]

Orchard Supply Aerospace grade tank fabrication material:

[mtothef]

Welding, courtesy of Mister Manners:

[mtothef]

Orchard SUpply Aerospace meets Winchester Auto Parts Suspension Parts Sale Bin Technology:

[Leecifer]

[mtothef]

Well, the tank is on, properly, for the first time since I got the damn bike. Now all I need is a front axle (Wednesday), low front fender (on the way, I'm told), headlight (ditto-ish), Mister Manners to fabricate a rally headlight ring/fairing mount and weld it to the headtube (can't forget the fork stops), make some new footpeg mounts to relocate new pegs back about an inch and also provide a pivot for the rear brake pedal and hydraulics, graft the YZ swingarm into place, weld a bottom link mount for the YZ linkage, figure out how to route the shock (which may or may not require kicking the airbox to the curb and making a new one), get the seat Renazcoed, twist up a low exhaust using the SRX headers (heck, that bike won't be ready for years yet anyway, so it's not as if they'll be missed!), and do something to remove that offensive wart of a rear fender/tail light assembly.

Piece of cake, right? Exactly. Thanks for reading, updates will follow, but probably not in any logical order. And if anyone out there is itching to unload an 18" rear wheel (preferably with sprocket and brake rotor) that'll fit a 99-07 YZ or WR, you know where to send it!:

[deadbird]

Nice work, let's get that seat mounted this week.
There is only one problem....
The welder is out of beer.

-Mr Manners

[mtothef]

Originally Posted by deadbird

Nice work, let's get that seat mounted this week.
There is only one problem....
The welder is out of beer.

-Mr Manners

We'll be sure to remedy that. Thanks again for all the help so far. Meanwhile, the delectable ms KLR unearthed a picture before it all went wrong (note strategic placement of BMW hardcase solely for purposes of confusion):

[johnnyandjebus]

You got my attention!!

[johno]

Gotta love those old Yammies

[Gadget Boy]

Nice distrubia!