K1 Hot Rod was named "The Rat Race" due to its former barn residence and what appeared to be a 22-caliber bullet hole through the seat where my imagination says someone took a shot at a barn rat.
I met the previous owner and original builder Steve Egli at a car show where he spotted my 750 Honda display. After a lengthy conversation he asked if I was interested in purchasing his CB750 parts collection. I was, and a week or two later my brother and I brought home a trailer and truck load of parts and bikes. This one was the most complete, so I started trying to do a simple "get it running" restoration while using many of the parts that I got with the bike and already had stashed for a future similar build.
It's a 1972 titled K1 cb750. Steve had gone to RC engineering and purchased a lot of the parts there in person.
The engine is an 836 that I did a few repairs to, it still has the RC rods and 836 kit, honed and re-ringed, re-built ported head, RC 315 cam and kit, Lockhart oil cooler, RC 4-1 header and Gerex ignition firing fuel from a set of Mikuni 29 smoothbore carbs with K&N pods or velocity stacks. It may have the last set of new adapter carb rubbers in captivity. I put the electric starter back on it for now and set the lightened RC flywheel aside.
The tank got a rinse with Evaporust this winter to resolve a few dark spots I could see inside.
The frame is mostly stock except the 2 1/2" extended swingarm that came in the parts stash, a needle bearing neck set, The two frame bars above the engine were cut so I added the bars from a parts frame and a Scottly made, 754 style bolt on kit.
It got the Lester mags that came with the purchase and a pair of tubeless radial tires intended for a top speed run at a track that since closed. Stock size 19" front and 18x3" rear with a 140/80-18 tire and a new/old diamond XL 530 chain running 18/48 sprockets.
I changed the triple trees from modified 550 parts back to a K1 Yamiya reproduction so the original gauges could go back on and rebuilt and lowered a set of F1 forks with new reproduction 550 tubes to get the ride height looking like a drag bike. The brakes are a pair of polished F1 calipers clamping a rotor that came on it and one that I drilled to match.
The seat, modified rear fender, Lucas taillight and 400 handlebars are off of Tom Campbel's old drag bike that has been on my shelf for years. The brake and clutch have Steve's old vintage Magura offset levers. Rear shocks are from a twin cam 750 my brother had since the Koni shocks I bought were too far gone to rebuild.