1974 KZ400 Cafe Racer Build

Jetting update: The 230 mains hit the sweet spot. Full, clean revs and nice chocolate brown insulators on the plugs.

ah you already had all my suggestions covered :whistle: ,nice work getting the leverage angles sorted.
sounds like you have the jetting dialed as well.


leon

Front brakes do a lot of the stopping, but the actual percentage can vary widely based on geometry, tires, and surface. The longer the wheel base, the more the rear brake does, and the Kz400 has a pretty long wheel base for it's size and weight. Going to an extreme, like a super-extended chopper, almost all of the stopping is done with the rear.

The Kz400's I've owned and ridden did a lot of stopping with the rear (not the majority, but a higher percentage than the inline-4 Kz's). The front brake would never lift the rear wheel before the front would slide. That means the rear will always be required for maximum stopping power (with the tires and road surfaces I was on).

The test is simply if you can lock the front wheel or not, while having your weight forward. If so, then you will slow faster by including the rear brake. Better tires make a difference too, so that will affect how much you want to use the rear.

On my 550, I can lock the front wheel, or lift the rear tire depending on how far forward I lean (and tire and ground conditions), but I could never get the rear to lift on a 400. I think there's just a lot more weight percentage up front on an inline-4, than a twin, with similar geometry.

On my buddy's Kz400, we put new shoes on the front, but there was almost no stopping power. It turned out there was a piece of casting flash that was causing the shoe to twist very slightly when the brakes were applied, so only one edge of the shoe was getting the full pressure. We had to grind that little bit off and that fixed it. I don't remember where the bit was, though, so maybe inspect the shoes closely for a possible defect. The ones we bought were new, but came off a dealer shelf and looked like they had been there for 30 years, judging by the inch of dust on the bag.

Very nice project by the way. Can't wait to see how the 650 turns out.

KZCafeChickNJ wrote: Jetting update: The 230 mains hit the sweet spot. Full, clean revs and nice chocolate brown insulators on the plugs.

230 mains?
If you were using the correct slide for a four stroke you could lean that down to a 145 jet.

And it looks like the 'chick' is a flipper.

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1974 Kawasaki KZ400 Cafe Racer - $6000 (West Milford)
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© craigslist - Map data © OpenStreetMap
Glen Drive
(google map)
1974 Kawasaki KZ400
condition: like new
engine displacement (CC): 400
fuel: gas
odometer: 3300
paint color: silver
title status: clean
transmission: manual
Fully customized bike with just under 500 hours of labor into it. It runs & rides like new and has just over 3200 original miles on the odometer. It needs absolutely nothing but a new owner. Clean title. Ready to register and ride. The bike has electric start as well as kick start.

Below is a breakdown of what was done. And by the way, I have a complete photo album of the project with nearly 600 photos as well as a daily breakdown of the work and the hours put in to it that the new owner is welcome to have after the sale.

The back end of the frame was removed and an upswept rear frame hoop was welded on.

The stock shock mounts were removed and custom 3-position shock mounts were fabricated and welded on. Aluminum body shocks with reservoirs complete the rear suspension.

The forks were rebuilt with new seals and oil.

The "commuter style" tires were replaced with higher performance Shinko tires and new tubes and rim straps.

Custom 3-position mounts for the rear sets.

Welded steel tray under the seat holds the 15 oz. Lithium Ion battery, all electronics & factory tool kit. It has a brand new regulator/rectifier unit from Rick's Motorsport so as not to overcharge the lithium battery. There are 2 discreet LEDs mounted inside the electronics tray pointing downward at the rear wheel hubs as an added safety measure so people can see the bike from the side in the dark.

All of the leftover tabs were removed from the frame and it was media blasted down to bare metal and powder coated to match the stripes on the tank, fender and tail.

Flush mounted LED tail light w/integrated turn signals & license plate holder tucks right up under the rear frame hoop with a custom fabricated and welded bracket.

The stock gauge cluster has been retained. It was lowered 3" so as not to stick up above the handlebars. The speedometer and tachometer are accurate and all of the lights, indicators and warning lights work properly.

The stock gas tank was heavily modified with hand-hammered knee pockets, flattened and smoothed top and a very trick flush mount pop-up gas cap was welded in. The petcock was rebuilt with new OEM O-rings.

The one-piece seat/tail combo was completely hand-fabricated out of aluminum and is held on by discreet wing nut screws that are easily removed to access the electronics tray and tool kit.

The upside-down Euro bars are aluminum and feature a Motion Pro throttle, new grips, new bar end mirrors and new switches.

The engine had its top end rebuilt with new piston rings, valve seals, and gaskets. All OEM Kawasaki parts aside from the Viton valve seals, which are a nice upgrade from stock. It didn't need the rebuild since it was running very well and had good compression, but when you're going this far with a project, you might as well freshen up the motor at the same time.

It has a new chain and 17 tooth front sprocket to replace the stock 15 tooth sprocket to compensate for the extreme weight loss of the bike. It's geared perfectly.

I replaced the stock CV carburetors with Mikuni VM32 round slide carbs, correctly jetted and tuned, and UNI pod air filters. The VM carbs are head and shoulders above the crummy stock vacuum operated CV carbs. The VMs are much more tune-able and open up a lot more horsepower & they have excellent throttle response.

Full custom welded & wrapped exhaust with new chrome shorty mufflers that are re-packable. The engine sounds incredible through this exhaust. Nice, throaty rumble while not being overly loud or obnoxious.

The front brake rotor is drilled and chamfered for better braking performance and lighter weight. (120 holes) The stock front brake master cylinder was replaced with a larger unit for better stopping power. The rear drum brake on these bikes doesn't do much, so you need a lot of front brake power, and this bike has it.

The bike is extremely light weight and nimble. In fully-loaded stock trim it weighed 387 lbs. With all the extra weight removed, it now weighs 312 lbs. Perfect for maneuvering through city traffic or letting it rip on winding country roads. It handles like a dream, has more power than your average 400 and is absolutely perfect for smaller to average sized riders. I'm 6' tall and it's just a little bit small for me. 5' 10" and shorter seems to be the sweet spot and the adjustable rear sets and rear shock positions will allow the new owner to completely customize the feel of the bike to his or her liking. I'll gladly service the bike after the sale if the new owner requests it.

I'm located about 30 miles outside the city and I can deliver the bike within 100 miles for free if the full asking price is met, but you must come here to go over the bike with me and complete the deal first. I will not deliver the bike on a promise that you will buy it. I've been burned like that in the past and I can't allow it to happen again. Absolutely no test rides without putting the full cash amount in my hand.

With all of that said, thanks for reading the ad. Please text or email to set up an appointment to see the bike in person.
Tim

newjersey.craigslist.org/mcy/5902108875.html


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