I've been laying low since the Big Freeze hit Texas. I think I've finally thawed out. lol That's a story in itself and all I have to say is try standing in water up to your ankles and brooming the cascading stuff from a garage for 8 hours. That's with the temps falling into the mid-20s * F and the water icing over as it hits the driveway.
Anyway, the report here involves a long-time desire to own, or build, a TZ750 dirt tracker. I mean come 'on, who wouldn't want to have one ?
Sometime in 2015 I stumbled upon news of Yamaha TZ cases being reproduced. Original 700 & 750 racers available will often have suspect blocks with worn tolerances and repairs. Kind of adds too much worry to an expensive proposition.
I figured I'd start with a fresh block and build from there. At the same time I'd learned CMR had built a few special frames for the project I envisioned. Their rep for road race apps was solid.
Following articles showing the case patterns being produced was amazing. The company was Kelgrif out of Australia. Those guys have amazing talents. In accordance, the finished sets were going to be expensive. I figured in the least I'd end up with a unique piece of mechanical art.
Moving along, it became obvious that acquiring the many additional parts to complete a motor was not going to be feasible. OEM items were becoming too " dear ". I figured as much, but what else can a guy do ?
The market is always funny. Just when things seem few & far between, a pair of complete racers popped up. One motorcycle in particular had been reworked with a set of new factory cases which were from Yamaha's final run. The parts are sand cast using a magnesium alloy. Those are the ultimate. The reign of racing TZ750s was over but the factory ran aprox 20 + sets to satisfy the needs of sidecar racers. I do not know the exact number produced.
Long story short became why part-out the cycle which is documented as Yamaha's prototype with frame bearing serial number 001. It's restored to museum quality and the seller cringed at the thought of damaging the " hen's teeth " cases. I understood & agreed, but I wondered if he didn't trust his own work. Hmmm...,. nothing ventured, nothing gained. The solution was buying both cycles. One for Show, & one for Go. The second bike is no slouch. It's ex-Don Vesco / Gene Romero with highly credible history. Gene placed on the podium at a string of AMA Formula 750 events during 1979 at Laconia, Sears Point, and Laguna Seca. Vesco set a record at El Mirage Dry Lake running over 189 MPH.
The Bottom Line is I've left the bikes as they are. The original goal hasn't gone away, but I feel maintaining status quo is the best plan of action.
Another shot of Gene on the Busch Beer / Vesco sponsored TZ, that I have on a 35mm slide. The other is a file photo of Don & his TZ in backdrop when it was on display at the San Diego Automotive Museum circa 1996. Godspeed to both, RIP.
The last I heard of the Busch TZ, was that it's in a collection near Vancouver, Canada when the owner tried to sell it on ebay & the reserve was not met, a few years ago.
It's a Sonicweld rig running a Suzuki X6 motor ( c. 1967 )
Number 55 should be familiar to most of you around the West Coast.
The mods are typical :
28 mm Mikuni carbs, Cylinder porting, Heads with compression releases, Custom exhausts, Right side shifting, ARD magneto, and No Brakes. The rear hub is a Triumph item.
The cycle is a quality build, runs fair enough, but not as fast as it should be. The ARD pointless mag is a single fire unit. For single fire ignition, the OE 180 * crank had been rearranged to run as a single. Later, the Sonic's crank was serviced and returned to OE specs with 180 * firing. Modify & Match works better than Modify & Mix. A factory-original, completely stock Suzuki TC250 is faster and turbine smooth. Those 6-Speed cycles were definitely quick for the times.
Here's an original, one-owner TC250 :
It still has its factory tires mounted.
The motorcycle was purchased new at " Iron Man " Kretz's dealership :
Yeah, I have some of the GP bodywork. The same metalflake stuff that has the U.S. Suzuki card laminated onto the bottom of it. The Sonicweld Titan chassis is OIF storage only, with only a drain line feed to the injector (kinda rare). It's seen some practice laps only at the Milestone Park track in Riverside back in 2018.
Pipes are spec built with rebuildable NOS Bassani silencers fitted.
Thanks for the compliment. It was a bucket list build & I tried to keep the theme true to the late 60's. The exceptions were the modern day Maxxis tires & the wider Marzocchi (think -late 70's Ducati) triple trees, that would retain the 35mm Ceriani GP forks. Keeping a low CG was critical too, in which I try to keep the front & rear axles aligned with the center of the crankshaft. The original rear alloy axle plates were MIA when I got the frame, so the engineering to meet this requirement was pretty straight forward.
As far as what Ray Hensley or Kenny Watkins produced for the 2-stroke OIF injector frames -that's an unknown for me. Over the years -decades, I've seen a few & this is the only one that I own.
The Suzuki Scrambler fiberglass is of high quality -thick & solid, which is something lacking in other period made aftermarket fiberglass.
Chassis looks good too, heck this might be her older / bigger sister
Just a hobbyshop-workshop vintage-racebike pastime for me since around '86 or so. I've seen a few of the later Trackmaster (Sonicweld) swingarm versions over the years too. Jeff Lessley has a real good one that he's raced at Perris with & a friend found the old alleged Don Greene-Jeff Sperry-Devon Sowell swingarm framed T500, that was modded to be a cafe bike, from it's old Class C glory days.
Agreed -It's been a been a great thread, all things Suzuki 2-strokes twins !