Topic: Possibly a new drag bike build. Maybe??

[dragracer]

I was recently gifted an old dragbike that had been abandoned in a storage facility.  I picked it up from Jacksonville Florida a few weeks ago.  The bike isn't complete and has been sitting since the mid 80's based on the date code of the battery i found in the chassis. Its got a 4.75" rear Sun wheel with a old slick, an extended swingarm and a RC  pipe. Sadly, one of the tubes is crushed about halfway shut. It has a drum brake up front so I'm guessing it looks like a CL 450 front end?? The engine spins over with some compression.  I'm guessing it's probably stock because I can push down the kicker with my hand.

At this moment I'm contemplating restoring it as a  wheelie bar and slick bike with some upgrades. It came with no bodywork so I'll have to figure which direction to go appearance wise. As far as the engine, it would be nice if I could put together another 72mm bore engine with a nicely ported head and decent lift cam. Nitrous oxide is definitely on the list. I pulled the engine off to lift the valve cover last night. I was somewhat hoping to find an aftermarket cam but to no avail.  It was very clean up top though. The engine wasn't oily at all and could have been freshened up prior to being parked. I did try dropping my scope into the cylinder to see if the pistons were stock. It was hard to tell but they appear factory. Nevertheless, I'm planning to toy with this thing for the next week or so and make up my mind which direction this will head.

[dusterdude]

Nice find frank

Sent from my SM-S711U using Tapatalk

[Jerry Rxman Griffin aka MuthaF'er]

Here we go 

[dragracer]

A few more when it was loaded on my friends trailer.

[dragracer]

Shop Dog helped me pull the engine from the frame. I need to remove the valve cover to see what underneath.  Likely just a stock cam. If so, that'll tell the rest of the story.

[Stev-o]

Would be a cool project to restore as a period correct racer! 

I have a small fairing sitting around if you are interested?

[scottly]

The front forks have the early 750 caliper mounts. Does it have a "unicorn" top triple?

[Don R]

 Nice find! There are a few goodies there, I wouldn't be anxious to grab a handful of that front brake though, the drilled strut looks like it's being pushed rather than pulled, but it did survive this long.

[dragracer]

I need to look at the top clamp Scottly. I know it's different than the later models I currently race.

[dragracer]

Would be a cool project to restore as a period correct racer! 

I have a small fairing sitting around if you are interested?

Thank Steve-o. I'll keep the fairing in mind if I move this project forward. My mind wants to build it as a wheelie bar bike. I really want to see if I can launch an SOHC based bar bike hard enough to get a low 1.30 to high 1.20 second 60' time. I'd like to see a 5.9xx 1/8th mile ET on raw horsepower as a target. I know a little nitrous oxide would make that number easily attainable.  The bike would need to be as light as possible so using light weight wheels and a 530 chain is important. I'd prefer to use the stock body work but that does add weight. I may be on the hunt for a  tank with a rusted bottom and just gut it out as a shell. I've got an aluminum fuel cell is could then use. That's how my mono shock bike is set up now. A backbone fuel cell would be more ideal and something to consider also. It'd be great if i could find a one piece Tracy body for a period correct look though.

I've got a mildly ported K head on hand already along with  set of 72mm MTC pistons. I'd send that head off to get oversized valves installed and a bit more port work to make it breath. I don't currently have a bored cylinder and would have to acquire a used one or get a stock block reserved and bored.  Someplace in my stash there's an RC315 cam though I'd much rather have a 327 cam. I know that cam works well as I have one in both of my dragbikes now. Connecting rods would be my next shortcoming to overcome. Upgraded rod bolts with stock rods might be something to ponder in lieu of aftermarket parts. My local guy is no longer able to get in the shop to work so I'd have to find someone to undercut the transmission without shelling out a fortune. As far as a clutch setup goes, I do have an MRE lockup that can be installed. I've got numerous choices to pursue for ignition controllers.  MSD, Pro Series 2, Dyna 4000 or just a simple DRL400 with a dynamic S plate. I'm sure I have a set of coils on a shelf in the shop so spark is pretty much covered. Carburetors are going to be an issue unless I buy new RS 34's. Of course they aren't free and would likely be my biggest expense on the build besides a new set of custom built wheelie bars. Its the material cost that'll hit me in the head. Labor won't be much because I have a good friend that'll hook me up. He's already done several sets for our KZ based dragbikes and and very satisfied with his work.

I've got the off season to make some decisions and collect more parts if I want to bring this old drsgbike back to life. Oh, and I'll graciously accept items from my friends here on the forum to make this resurrection happen😅🤣😂

[scottly]

I'd prefer to use the stock body work but that does add weight. I may be on the hunt for a  tank with a rusted bottom and just gut it out as a shell.

It'd be great if i could find a one piece Tracy body for a period correct look though.

When Bill and Sam were at Gary Pena's place picking hot rod parts, they got a fiberglass stock-looking tank that was basically a shell with a small tank built in. They also got a Tracy body.
FYI, the unicorn triples bring a premium price, since they tend to break easily, and K0-K2 restorers need them.

[Don R]

 True on the unicorn triples, I bought my last one from Yamiya, cheaper than Ebay and made from better aluminum which is reportedly difficult to break. I used a JDM one on my recent K0 assembly, it has the hole for the speed warning light.

 I see CycleX has a big tire looking Gary Pena new old stock chassis. There is also an aluminum RC Engineering frame with a Ceriani fork and Borani rims. Look under high roller parts.

[dragracer]

I'd prefer to use the stock body work but that does add weight. I may be on the hunt for a  tank with a rusted bottom and just gut it out as a shell.

It'd be great if i could find a one piece Tracy body for a period correct look though.

When Bill and Sam were at Gary Pena's place picking hot rod parts, they got a fiberglass stock-looking tank that was basically a shell with a small tank built in. They also got a Tracy body.
FYI, the unicorn triples bring a premium price, since they tend to break easily, and K0-K2 restorers need them.

Unfortunately one side of the top tree is broken. I discovered it when I decided to loosen all the triple tree bolts to slide the fork cubes up. I wanted to lower the front of the bike to match the rear to see how much ground clearance I'd have once the chassis was somewhat level. The daggum top bolt was already loose. That when I saw the freaking Crack. As luck would have it, I accidentally broken the other side myself while trying to pry it open slightly to move the fork tube. Oh well.  So much for the desirable unicorn triple. Now I've got no choice except to change out the entire front end. I'm on the look out now for a complete front end with axle and spacers if anybody has a c g cap one laying around. Odds are I'll have to buy new, custom shortened tube from Cyc K e Ex to meet my specific needs. I'm looking at needing a 25" set up now, centerline of axle to the top clamp.

[Don R]

 I built one using F1 lowers and 550 tubes, it's in the storage unit right now or I'd run out and measure it. I do have one with no engine that's 550 tubes and K4 lowers, I will measure it. I think later 750 top trees will interchange, as long as they're not F models.

[Don R]

 Center of axle to top of the triple tree is 27 1/2" that's with nothing sticking above the top tree, on the side stand and no engine or exhaust. I'd guess with an inch of tube slid up and standard weight engine it would be close to 25. I'm sure you have experience with it that I don't, just sharing my numbers. The replacement tubes were 21 13/16". I got them before the price doubled when a supplier went out of business.
  The frame it's on is raked a few degrees. it should sit pretty low and have some clearance since the turbo exhaust goes out high on the left.