EX500 Build

[dorifto240]

A friend of a friend asked me to build a bike for him. We talked a bit about what he wanted, and I started coming up with ideas.

He wanted a sport bike, no more than 600cc, and it had to have undertail exhaust. He's never ridden before, so I was looking for something easy to control, but not too small to be outgrown easily.

We settled on an EX500, and I got started. I picked one up from a guy I knew, I wish I had some before photos of it (they were deleted: It was rough. It had been dropped off a tow truck at one point, which had wrecked most of the body work.

After talking with my boss, who used to race EX500s, it turns out that the front suspension can be a little squirrely. Upgrade #1 and while I was at it, I wanted to scrap the drum brake setup on the rear wheel.

I picked up an early ZX600 Front and Rear setup, and after a few mishaps ordering bearings, The front slipped right into place. After a few hours with the grinder, some cussing, and a bit of prayer. The rear swingarm slipped in as well. Easy Peasy.

The EX500 runs 520 chain, and the ZX600 runs 530, but Kawasaki used the exact same hubs on both rear wheels, so the switch back to 520 was a piece of cake.

[dorifto240]

The only problem with most 80s sport bikes is their tail sections. They remind me of the original Cylons from Battlestar Galactica, the one's that fell over all the time. Awkward robots with equilibrium problems do not project an image of speed, in my opinion.

I began some rummaging at work, and found some useable body pieces from another EX500, with some bubble gum and duct tape I figured I could pull one whole set of fairings together.

So upgrade 2 was tackling the rear tail section.

A few zips with a jigsaw, and some fiberglass resin later, and I went from this:

To this:

It's a bit hard to tell at this angle, but I cut and narrowed the the sides of the tail to follow the curves that came off the seat section and grab rail. I also shortened the height of the tail section, to give it a bit more upward slant. While I was at it, I glassed the side panels, the grab rail, and the tail piece into one piece. Instead of tabs, screws and rubber grommets holding the tail together, 4 bolts keep it nice and secure. 2 of which hold the grab rail to the frame. It's not going anywhere!

The front fairing was toast, out came the jig saw, a bit of JB Weld to help hold everything together and even more fiberglass. While I was at it, I filled in the turn signal mounting holes as well.

Upgrade #3 is an undertail exhaust, here's my rough idea:

[redkow97]

upgrading from 16" to 17" wheels is worth the hassle on an EX500, but the suspension upgrades might be more than the flimsy frame can handle.

I highly doubt you'll hurt anything, but it may not improve as much as you're hoping.

If you manage to work out an undertail exhaust that looks half-way decent, you could sell a "kit" on www.ex-500.com for big bucks.

If I hadn't sold my EX to fund my track riding, I was planning to slap a circular headlight on it, and rig up some kind of under-body exhaust like the EX650. Just rat the bike out and turn it into a hooligan machine

Good luck w/ your build. Lots of parts on ex-500.com too, if you're needing something. Parts for the first generation can be slightly harder to come by, but there are a fair number of them on that site.

[dorifto240]

upgrading from 16" to 17" wheels is worth the hassle on an EX500, but the suspension upgrades might be more than the flimsy frame can handle.

I highly doubt you'll hurt anything, but it may not improve as much as you're hoping.

If you manage to work out an undertail exhaust that looks half-way decent, you could sell a "kit" on www.ex-500.com for big bucks.

If I hadn't sold my EX to fund my track riding, I was planning to slap a circular headlight on it, and rig up some kind of under-body exhaust like the EX650. Just rat the bike out and turn it into a hooligan machine

Good luck w/ your build. Lots of parts on ex-500.com too, if you're needing something. Parts for the first generation can be slightly harder to come by, but there are a fair number of them on that site.

Thanks for the info and the idea for the kit. It actually looks a little easier than I first thought it would be, we'll see how it turns out.

[redkow97]

if you've got the bike apart and have welding equipment, gusseting the frame may help, and get you your money's worth out of the better suspension bits.

you might also consider going up a tooth or two in the rear to compensate for the fact that you increased from 16" to 17" rims. Not vital, but I think it would make all the difference in the world as far as the butt dyno is concerned. It will FEEL quicker. As long as it doesn't cruise over 7,000 RPM on the highway, I'd keep it that way.

[TheBrown57]

For some different parts possibly look at Kawasaki 454ltd they are essentially the same engine, its the bike I had last, great bike very fast for a 454cc cruiser and I had some EX500 parts on it since they are easier to find and fit just the same

just my 2cents good luck with the build

[dorifto240]

if you've got the bike apart and have welding equipment, gusseting the frame may help, and get you your money's worth out of the better suspension bits.

you might also consider going up a tooth or two in the rear to compensate for the fact that you increased from 16" to 17" rims. Not vital, but I think it would make all the difference in the world as far as the butt dyno is concerned. It will FEEL quicker. As long as it doesn't cruise over 7,000 RPM on the highway, I'd keep it that way.

Strangely enough, the 85 ZX600 I pulled the front and rear setup from had 16s as well, as it stands right now, now need for the sprocket upgrade. I'm going to leave that conversion up to the owner of the bike, if he wants to at a later date, that's his decision.

Gusseting the frame is a definite, especially given this fun little bit:

Don't worry, the crack is going to get welded in. Then that section is going to be boxed to give me a little extra piece of mind.

Turns out this bike had been dropped off a tow truck. Like I said, it was rough when I got it

[wht_scorpion]

Dude do a advance Ing. and a shift kit and a factory jetting kit

[redkow97]

For some different parts possibly look at Kawasaki 454ltd they are essentially the same engine

Truth. The 454 was basically half of the Top Gun "Ninja" ZX9 (really a 908).

Then they bored out the 454 to 498 in 1987. That's why it's so hard to get (reliable) power out of the EX engines. They're already bored to the point that the cylinder walls are pretty thin.

[fazer1sniper]

So what's the status on the build?

[dorifto240]

So what's the status on the build?

My big boy job took precedence for a bit of time, but I've been able to slowly work out some things.

The tail piece looked okay, and then I found a Suzuki tail light in the $5 bin at Rice Paddy. A few brackets later, I had it in place, and then got crazy with the fiberglass. Again.

I just taped a line off the grab handle, and then started glassing. I like it. I'll trim everything up, and smooth it out with a bit of filler.

I went a different direction with the exhaust, owing to a complete lack of skill, the welding for the undertail exhaust was to difficult. So I convinced the owner to go with an underbike exhaust, ala Buell.

Two welds, with no crazy bends > 4 to 8 welds and a bakers dozen of complicated bends.

I'll get photos of that up soon. I'm really proud of it.