The new 1984 IT490 build thread...

[Vonski]

Recap of the old thread:

My brother bought the bike new in '83 and a year later it was cart-wheeled at high speed out at 5-mile. It more or less sat for 30 years with a bent/broken sub-frame, exhaust, and misc. other parts only to be fired up occassionally. He gave it to me so I could help him sell it in 2012, but I talked him out of it and and the build started there.

Well, we've picked away at it until the most recent push to get it done this summer. Old and new pics coming...

 

[rholbrook]

So excited for this thread

 

[Rot Box]

So excited for this thread

Me too. There's a special place in my heart for fire breathing monsters

 

[Vonski]

This was how it looked when we started. Its complete and in good shape, but with plenty of issues lurking.

Edit: I had forgotten, but the day I brought this to my house (where I used to live in Herriman), I actually got it started and rode it. There was 1/4 inch of old premix sludge coating the bottom of the tank (which makes sense since we used to run stuff around 24 to 32:1) I cleaned the tank and petcock, put in some new fuel, and threw in a new spark plug I had laying around from some other 2-stroke (dimensionally it looked good, so what the hell). Anyway, it started after about 20 kicks and idled and ran really well. With a four finger clutch pull and tires and tubes from '84, I bombed around the neighborhood until I remembered how old it was and took it home.

 

[Vonski]

First thing was to get rid of the two biggest problem items... ridiculous forks and front drum brake.

 

[Vonski]

Next, it was time to figure out the donor parts for forks, triple clamps, and front wheel with disc brake. Of course, finding all of these from the same bike and source would be ideal. Luckily, B2 Bomber (sorry man, forgot your name) here on RME had what he thought would be the perfect parts from a Suzuki DRZ400 he was parting out (he hooked me up with the DRZ digital display too, which is gonna be pretty badass). Once I confirmed that conversion bearings were available for the dimensions of the IT head tube and the DRZ triple clamp shaft, donor parts found! What I love about these forks is that they're the conventional design and have boots, yet are modern enough that they can be made to perform well like an inverted fork. In my opinion, an inverted fork wouldn't look right on this bike. As a bonus, the spring rates for a stock DRZ should be pretty close as-is, but we'll see. A Dunlop Geomax tire was mounted up too.

BTW, All Balls Racing has the most complete conversion bearing chart I've ever seen. Its pretty nuts.

 

[jeeper]

My first 'real bike' was a 490.. What a rush! ...and what a dumb bike for a 150lb teenager to ride!

 

[Vonski]

One thing I've thought about a lot (and probably too much) is that we have no clue how this thing will handle with the changes we're making using modern suspension and controls. It most certainly will work better that it did stock, but its an unknown. The stock rake of the forks is noticeably steeper than a modern bike. Not sure if that will be a good or bad thing, so I've left it alone for now. I can see this thing being a perfect candidate for a steering stabilizer though, but I want to see how it work without one first.

Edit: My bad, what I meant is the forks are not "steeper" (is that even a word?), but on more of an angle. Like a chopper, that's better.

 

[Vonski]

My first 'real bike' was a 490.. What a rush! ...and what a dumb bike for a 150lb teenager to ride!

I know what you're sayin', I rode this 490 a little when I was 13, and didn't weigh more than 120. I could only start it with the kickstand down and using all my weight.

 

[Vonski]

Next, we had to deal with a poorly fitting pipe (well, and muffler). I've never heard of anyone ever having good luck with this without cutting and re-welding them in at least a couple places (even new ones!). I'm sure the wreck(s) didn't do it any favors, but it never fit well. After some cutting and a couple slice/bend fixes, it shouldn't be puking premix and melting plastic anymore.

The plan is to test it out, then pretty it up for a coating of some kind (suggestions welcome... ceramic? high temp. paint?). Also, I've wondered if an outfit like P3 would take a custom pipe and make a carbon fiber guard for it. Its pretty important that we protect this one.

Edit: Also mounted a Dunlop Geomax tire on the rear. A 120/80 should hook up pretty good I figure.

 

[Vonski]

All of the above was done over late '12 and early '13 before being thrown on the backburner until now. More recent pics coming...

 

[Rot Box]

The plan is to test it out, then pretty it up for a coating of some kind (suggestions welcome... ceramic? high temp. paint?). )

My dad used to coat his exhaust pipes with vegetable oil (think Crisco). He'd get the pipe up to temperature then rub the the oil all over it and let it bake in. They looked very nice and it kept the rust off. Kind of the same concept as seasoning a dutch oven..

I use paint but it burns off quickly near the manifold and you have to re-paint them often :-\

 

[Vonski]

My dad used to coat his exhaust pipes with vegetable oil (think Crisco). He'd get the pipe up to temperature then rub the the oil all over it and let it bake in. They looked very nice and it kept the rust off. Kind of the same concept as seasoning a dutch oven..

I use paint but it burns off quickly near the manifold and you have to re-paint them often :-\

I remember people giving their uncoated pipes an occasional hot WD40 rubdown as well.

 

[Vonski]

Rasied the bars up 1 1/4", Renthal bars, Cycra handguards, new grips, and leaving the stock clutch lever for now. The clutch pull is evil, but a new cable from Motion Pro is on the way. stock throttle tube and throttle cable work fine and will stay in place for now. The DRZ display was moved a little to better accommodate the IT headlight/plastic, but that stuff and the switch and wiring still needs to be done. No plans to run a battery, so the clock won't keep time and obviously won't display any info when not running. Not a big deal. However, does anyone know if these can be reset/reprogrammed? (under most circumstances this falls under "mileage tampering") . Not a big deal, but the previous ODO info will be stored. it would be kinda cool to start from zero. :greg:

 

[Vonski]

BTW, the current front brake master cylinder will work fine for testing, but I'd like to replace it with a version that has the banjo fitting threaded in from the front (not the side) for better hose routing. If anyone has a Japanese bike with a Nissin setup they're parting out, let me know...

 

[Vonski]

New x-ring chain, new Dunlop (mentioned above), new chain guide parts (to replace the broken ones), and had Pro Action up here in Heber rebuild the shock and recharge (no re-valve at this time). We threw the stock spring back on temporarily, but its waaaay too soft.

On the shock spring, my research is showing it as a 4.0 . Just sitting and bouncing on it with all of my 150lbs. lets me know that I'd be bottoming it out with ease. By comparison, my 300 has a 5.4 stock.

So this is where I want any and all recommendations if you guys were shooting for a 185# rider. Better yet, if anyone has a spring (or springs) with the right dimensions and heavier rate I could borrow, great. Otherwise, its gonna be hit or miss guessing on springs at around $100-$120. If I mount up a spring and take to the desert for testing, I wouldn't feel good about trying to return it, ya know?

 

[I Lean]

How hard would it be to take the 5.4 spring off your 300 and put it on this bike for testing?

 

[Vonski]

How hard would it be to take the 5.4 spring off your 300 and put it on this bike for testing?

I've got a 5.2 for the 300 on the shelf. Betting its not the correct ID and length, but maybe I should check before assuming.

Edit: After visiting the Race Tech site, they're really different dimensionally. FWIW, I'll be needing a single rate, 66.9mm ID1 / 64.4mm ID2 x 267mm long coil. I could try and make a guess based off the 300, but the IT shock is at more of an angle, so that'll throw things off a bit.

 

[Vonski]

A few more...

Side plastic in good shape, but not shown. Tank is also good, but due to discoloration (where the stock stickers were), the IT logos will be printed onto a (blue) color matched sheet, then cut to the shape of the tank sides.

I decided on a shock spring rate, but haven't found a yellow one yet. Worst case, I'll go non-yellow or have one blasted and re-coated.

Headlight/number plate will get mounted next along with other misc. items.

 

[sixstringsteve]

she's a beauty