Café Corner

Well, to sum things up for those that haven't been around, we've taken a completely stock, mint, 400F and turned it into a nice race bike. Here's the story...

Actually the owner is my good friend Eric Yuzon, a distinguished engineer with an eye for real art, an exceptional if not professional photographer, and an all around nice guy. Ok, I'll take the keys to the new BMW now Eric! That said, he's also just acquired two more 400Fs in various states of condition and that makes three. The first one (above) has in fact been completely disassembled and the frame stripped with the intentions of making this bike into an AHRMA legal race bike. With some exceptions, we've succeeded, to a point. Now for the pics below of it's current state of health;

Please note - these are thumbnails - the real pics behind them are of the best quality, but *huge* so if you have a low bandwidth connection (dial-up), I suggest clicking on one and then grabbing a beverage from the fridge while it loads.

Eric and I have been tasked with the dubious honors of cataloging everything that's being done to this machine, and how. (Don't even think of telling me this is the first you've heard of this Eric!) The Akront rims, spokes, special hubs and forks and rearsets and stuff have all been a meticulous process in acquiring as there aren't too many of these *really tricked out* around any more. By the way, the rearsets are of the 900RR variety. And they look sweet too. As soon as the "parts list" is generated, a report on latest progress will be posted. As of right now, the other three 400F's are being considered for various ...purposes. So lets all give Eric a big hand for the progress made so far and wish him well finding those rare and hard-to-find parts while I take his new Beemer out for a test ride. It's new, it needs to be "broken in" anyway.

Updates; 10/02/02

Here's some info on the new motor:

....an original Yoshimura engine that we haven't really even begun to get into yet.

Frame:      (go below for nice pics of the welds!)

• Stock CB400f frame; modified (shaved brackets) & strengthened with steel box sections near pivot point. 
• Comparison of stock frame. Pics 1. Pics 2. Pics 3. Pics 4. Pics 5. Pics 6.
• Swingarm: bronze bushings & braced. 

Rear suspension:

• Koni shocks, 95-115 ft. lb. springs. Out of production parts.

Front suspension:

• CB750f2 stock 35mm forks.
• VF500f triple clamps with sleeves to mount 35mm forks and tapered head bearings. 
• Progressive Suspension springs.
• Aluminum fork brace.
• Steering damper, triple clamp mounted.

Body:

• Custom CR450 replica alloy fuel tank with knee indents and Monza alloy fuel cap. Here are the Honda Vintage wing decals.
• Airtech Vesco 3 vintage seat.
• Fiberglass café race fender. Origin is unknown.

Controls, instruments, etc.:

• Pro-Flo 35mm quick-mount clip-ons with replaceable tubes.
• CBR900rr adjustable brake lever.
• Tommaselli adjustable clutch lever.
• CBR929rr rearsets & modified linkages on custom brackets.
• SL175 tachometer, rubber mounted on custom bracket. NOS.
• Sigma BC800 cycle speedometer / odometer.

Brakes & wheels:

• CB750f steel rigid 6 bolt discs.
• CB750f dual piston calipers. 1981 on. Calipers will be trail mounted.
• CB750f 6 bolt front hub.
• CB400f stock rear drum, lightened and vented with machined holes.
• Akront aluminum WM-3 polished rim laced to front CB750f1 front hub. 
• Akront aluminum WM-3 polished rim laced to rear CB400f rear hub. 
• Buchanan heavy duty stainless steel 8 gauge spokes and 0.281" nipples. These pictures show a comparison to stock parts.
• Dunlop GT501 racing tires (new tread design, was K591).

Drive train:

• Convert from 530 chain to 520 chain; change sprocket ratio. Sprocket Specialties custom 520 sprockets.
• SL350 stock 16t front sprocket.
• SS 40-42t rear sprocket.  ...more variations to come.

Engine:

• OMT/Yoshimura performance full race exhaust system. - Ceramic Coat
• Yoshimura 458cc kit (51mm to 54mm bore).
• Megacycle MILD cam grind on stock core & Megacycle HD valve springs.
• Keihin CR 26mm round-slide carbs w/ velocity stacks & K&N filter pods.
• Dyna S type electronic ignition with high output coils.
• New Honda oil pump (larger capacity) & oil cooler.
• Catch tank (per AHRMA rules.)

Electrical:

• No starter/system.
• No key switch, hidden toggle.
• No turn signal system.
• Gel type battery. Total loss system.
• Heh, heh...we don't need no stinking lights!

Performance pre-data:

• Weight & power = 392 lbs. Wet & 355 lbs. dry. & 37 hp. Power to weight = 10.6 lbs./ hp.
• Target weight & power = 275 lbs. dry & 50 hp. Target power to weight = 5.5 lbs./ hp. (50%!!).

Misc shop stuff:

• My cool home made blasting cabinet.

Update: Dec. 31st, 2002 - 

We purchased a few 400F's at Mid-Ohio last summer and Eric found another old tired race bike out in Jersey (I think) and it was apparently a real "Yosh" race bike. He got a pretty good deal considering it had been passed on from one owner to another and the only thing we could recognize was the Yosh pipe - hence the good deal. Well, as it turns out, the top-end and pistons as well as the complete exhaust system were indeed Yoshimura! and all is in fine shape too! 

1. Completed frame with the alloy tank & bracket, rearsets & brackets and seat brackets.
2. CBR929rr rearset; brake side.
3. CBR929rr rearset; shifter side.
4. I also had all the open welds tig-welded shut. Weld 1, weld 2, weld 3, weld 4, weld 5. Seat area welds.
5. Here are the tank and seat brackets.
6. Here is a square, strengthening bracket behind the swingarm pivot. I have a feeling it will interfere with the chain. So, it will probably get cut off and moved higher. Also, I would rather have a round tube vs. square.
7. Now, I removed the cylinder heads of the rumored Yoshimura engine. Lo and behold, it is a Yoshimura 458 piston kit! Notice the larger "eyelids" on the piston tops. Bad news is that one of the cylinder liners has a bad gash and will need to be replaced. A new one will have to be re-bored and pressed in.

    

    

   click this to review a sweet Yoshimura 400F article!

   Thank you Vagn from Denmark!

We've learned a lot about blasting our parts and painting, polishing, carb work and tuning on these older bikes and I think we've really come a long way but actually know what we're doing now.  Stay tuned for more info!

A sign of Eric's undying dedication and loyalty 

click it!      click it!

If you have any ideas, comments or suggestions, please, by all means, send me an email.

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This is serious business. Some settling may have occurred during shipping and handling. Batteries not included. The oil isn't always checked on the centerstand - it's usually in the engine.

Last updated (probably in my sleep) June 26, 2008 07:20:07 AM