Very, very cool
I was working on a Kawi Superbike team here in the PNW back then, and we ran enough California tracks (when we could afford to) that we probably have seen each other. Mostly we ran SIR, Portland, and Westwood up in BC. We loved Westwood because it paid better. We had pretty good sponsorship (Yoshimura, Fox, Kerker, Megacycle, D.I.D, MDS ignitions), and the local Kawasaki shop's van was our "transporter". It had only two seats. The rest of us had to sit on a bare metal floor in back with our legs under the bike and huffing gas fumes from the jerry cans.
Typical mongrel from the day. Our bike was originally built by Krauser, and they threw a bunch of money at it. But all it did was blow the fuck up on them (which takes some real talent with a Z1), so we bought it in 1980. Over the next year we changed damn near everything but the gas tank...and we re-painted that (which put Krauser's nose out of joint, but our attitude was: "Want that paint job to stay? Pay us"
The frame was classic "cheat like hell": About 80% of the stock tubes were replaced with thinner wall cro-mo. It had some hideous solid aluminum disc wheels when we bought it (geez, remember those?), which we replaced with morris and then dymag.
We re-designed the rear suspension to move the shocks up on the swingarm and lay them down 34 degrees. I was really happy with the way that worked out.
We had a trick set of genuine Yoshimura racing forks, but they had thin wall 36mm tubes and were shite. We built up a set of GS1000 forks (beefy 37mm tubes
), ran S&W springs from a Goldwing, and modified the dampers. We ran triple clamps from a Suzuki cruiser, because they had an extra set of bolts in the lower clamp and a lot more clamping area, and had a lot less offset than stock. They worked pretty well.
We had Fox remote reservoir shox, and we set up the low speed compression and rebound damping "medium", the high speed compression damping "fuck-all", the high speed rebound damping 'firm". We ran as little pre-load on both ends as possible, and changed spring rates when needed. To this day I hate pre-load. It just screws things up. Generally, if you could get a bike to handle well at Westwood (and ours did), it would handle well anywhere (OK, except Daytona, but Daytona is a freak show with banking). We probably ran more suspension travel at both ends than just about anyone, but that really helped to not overload those flexi-flyers. Those beasts were just not stiff enough to run short travel suspension with firm spring rates.
We ran Lockheed calipers and 13" rotors.
The crankshaft was a welded stocker (bomb proof, but heavy, I always wanted to build up a lighter crank but we never had the scratch), We ran Yosh single ring high-silicon cast
(yeah, that's right) pistons. Those pistons were wonders: Bullet proof at high rpm and sealed perfectly every time. The heads were from Yoshimura, Branch, and later we got one from Kenny Augustine (but never raced it). Augustine's stuff impressed the hell out of me. The Yosh heads were all top end. The Branch heads were really nice all-around. We never ran more than 11:1 CR, as it killed the combustion burn (and top end power) above that. 11:1 was a good match to the cams. Squish clearances were 1.0 mm
We started with Yosh cams, but switched to Megacycle (they still list the #470-65A we ran) and they made power everywhere with 110 degree lobe centers. Yosh gave us inverted buckets that were much lighter than the KZ-650 stuff everyone else ran. The valve springs and Ti keepers were S&W from Branch. We had a racing D.I.D camchain from Japan (Yosh again), and the camchain tensioner was mechanical.
We got the bike with two sets of Yoshimura CR transmissions (really nice stuff), and the clutch was banded and had Barnett plates and stronger springs.
We had a "real" Kerker racing exhaust (the one they gave
you that you had to weld up, not the one he sold). You knew you had arrived when Kerker gave you the good stuff (Same one he gave Muzzy and others)
As far as I know, we ran the first prototype MSD ignition for a motorcycle, and if someone else had a rev-limiter before we did, I never heard about it. We never needed more than 28-30 degrees of advance with single plugs.
We ran nothing but Castrol R (ahhhh, I love the smell of bean oil), and would change it twice on a weekend. We ran an MG oil cooler with AN fittings welded on.
We ran Goodyear slicks. We tried Michelins and Dunlops, but Goodies worked best.
The whole thing weighed 388 lbs (with gas), and made @135-140 BHP. It was as reliable as a pile of bricks with the following exceptions:
- Never let a flat rate mechanic tighten anything smaller than an axle nut. We had a guy helping (he was no dunce) that was the service manager for the local Kawasaki shop. His specialty was stripping cam bearing bolts.
- Those CR 31 Smoothbores were very weak in the main jet boss area. Over tighten a main jet, and you would crack the boss. That little crack would allow enough air to pass to weaken the main jet delivery. One cylinder goes lean...Engine goes poof. We found this early and used the spare set we had. We also think this is why the Krauser bike kept blowing up...they ran a whole season with a cracked carb body. Ours didn't blow up, and we were making a lot more power than they did. After the first year we were running Sparky's "Blue" carbs (from Branch) which were 34mm bodies with the AMA mandated 31mm restrictors, some really nice transition pieces between the carbs and the head that Jerry Branch gave us the dimensions for that made the motor believe that there was no carb restriction, so it was a moot point after we made the change.
- Never let an idiot grind the lifter bores for cam lobe clearance. I used to set them up with about .020"-.040" clearance (the cams did walk around a little at 10K+ RPM). Idiot decided we needed more. Modified it on his own without telling us. Removed half the support for the lifter. RH exhaust lifter blew right out of the engine at Laguna when we were running top 6 or 7 (took a good chunk of the valve cover with it). The engine still ran five more laps to the flag, dousing the rider (and God knows who else) in Castro R firing on three cylinders. I think we wound up 13th or 14th, which was impressive for a 750cc triple
Other than that, it was completely reliable. We would do the top end every race (lap the valves and re-shim the springs, if needed, to get the seating pressures back where we needed). Cam chains, valve springs, and pistons every three races, new drive chain every two (hey, they were free)
We won a bunch of races (and a few track championships) in '81 and '82. Those were very good years, and the purses more than covered the expenses.
The AMA pretty much fucked us when they switched the class to 750's, and chose to do so in the middle of a recession (We had a deal lined up for Bardhal to sponsor the whole show for about $60K/ year...my how times have changed...but they pulled out when the economy tanked). We had no resources to build a brand new 750, and had no interest in running a warmed-over stocker mid pack. The rider moved onto BOTT, and I had to go to either Hell or Texas. I chose Texas. But we all had a hell of a good time for a few years. I love that era in racing.
PS - Wish I could find some pics. It was a 1979 Mk-II with a black tank and silver knee panels. Big ass Yoshimura sticker on the tank. Maybe mom knows where they went. Hell, I would love to know where the bike went (it was sold off as club racer, and last I heard succeeded in scaring the living shit out of the new owner...no, you can't buy wins), or maybe I don't. Old racing bikes rarely have happy endings.