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So, lamenting the fact that buying a house has put just about all of my motorcycle projects on indefinite hold... I stumbled into a new one. A coworker gifted me what he described as a total rat 1980 CB650 so his father would stop pestering him about getting it out of the garage.
I picked up the 'rat' on Saturday, turns out its actually pretty close to streetable as is.
It needs a tank, the gascap is missing and it's rotton/leaky.
It needs one fork seal replaced.
Countershaft and or shift shaft seals are shot.
The horn button is dead.
The high beam indicator light along with the right turn indicator light in the dash are dead.
It needed a battery, that has been rectified.
The carbs need a good cleaning as the pilots are clogged.
My goal is to turn this into a modern'ish cafe racer, with the emphasis on racer. No, I'm not completely cracked, it won't be showing up in ULSB any time soon*.I'm going to build it to the USCRA's Formula 2 ruleset.
In a nutshell, F2 is based on bikes made up to 1985, 650cc or smaller air cooled four stroke, 500cc air cooled two stroke or 350cc liquid cooled ring dinger.. It must use a steel frame if a four cylinder. The only other restriction is forks must be conventional. Beyond that, if I can show the concept/design was in use in that period, I can use it.
Step 1 is going to be making it roll and stop reliably. The stock suspension and brakes are well... pathetic. I'm thinking a set of CBR wheels, F3 or F4 forks and swinger will sort that side of the equation out. At the same time the frame is going to need a lot of the welds redone as Honda wasn't all that consistent with them back then. Extra gusseting is in the playbook as well.
Step 2, making it ridable, new tank, seat and controls. Rearsets of some sort, I'm thinking if I do it right I can find a bike that uses something close to what I need and just weld up brackets to match. I'm also going to redo the wiring harness from scratch, I don't feel like getting stranded/loosing thanks to 1980 electronics giving out on me, nor do I need that complex a wiring harness.
Step 3 is going to be setting it up to be street legal when desired. A taillight / turnsignal / plate bracket that just plugs in and mounts with a couple bolts will be easy enough. I've got an idea for a similar front setup that'll contain the headlight, turn signals and horn that should be quick detach as well. At that point it'll be a matter of popping the mirrors and sidestand off, mounting the front number plate and rolling through tech as I plan leaving it wired at all times as well as sporting a stylish belly pan.
Step 4 will be motor work, although I doubt I'll be doing much beyond basic preventative maint this year. The stock motor should be putting down an asthmatic 40 to 45 hp at the rear wheel. 70+ is more than doable without doing crazy mods and staying under the 650cc cap, but thats for down the road. (I have a writeup on earlier period Honda 750 SOHC racers documenting machines that started coming on the pipe at 12k RPM and held it to 14k RPM, with 16k being safe overrev?! I so want to replicate THAT setup just to see the look on people's faces when this thing screams by. Given my prior experience with similar 2v heads I think it's entirely doable too...) Handling takes priority right now, if I'm loosing due to power down the road, THEN I'll go crazy Kurlon on it.
The big challenge on this bike is I have basically zero budget. Any cash I can scrape together goes towards repairing the KTM so I can play in LRRS again. Hopefully, as the parts I want to use are 'old tech' for current racers they'll be around cheap or free?
*The fact that I'm also 100% within ULSB rules, and if I get the motor where I want it on par powerwise with most Hawks is pure coincidence.
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Originally Posted by Pookie
