Years after getting this bike home from the States with the help of  quite a few friends, years after it last ran, after months of tinkering with it, running about finding parts for it, or as I put it:

15 years for finding a genuine A1R
15 months of  work

all for 15 hours of “fun”! Insert Big Grin emoticon here.

You’ll find a map of the track here as well as a bit of info about the race, one of the oldest in Switzerland.
I hope I’ll be able to send a vid of the race as One of my friends had a camera onboard… and he blew me away!

Here it is on Google maps. And with a satellite view. It is a normal road with lots of Police controls normally as it’s a fave with local bike nuts. But once every two years, it’s blocked by the same cops who fine you and becomes the local replica of the “Mad Sunday”.

A slightly tense Spike

This was supposed to be summer… a very chilly morning, curtains of rain, all that with a brand new bike, with a new gearbox, new tires and a new rider… Can you you say uncomfortable?

I only did one of the runs before retiring wet and cold (10 degrees for F sake!).
Not fun at all.

Thankfully at mid-day, the sun appeared and dried the track… the rest of the day was thouroughly enjoyable.

This is getting better…

Better still…

I'll zip up my leathers next time, promise.

You really get into the game after a few runs, the track is a miniature Deal’s Gap, 7 kilometers long, a lot of blind curves, most curves cantered… Takes a while to get used to it. To make it more interesting, it is in the middle of a forest and the road is flanked by ravines: wiping out is NOT an option.

I did my first run with a non-functional gearbox, I was stuck in second gear. The clusters needed to be run-in. Thankfully, by the second run, it loosened up and got better and better. Thanks to Ellis of Moore Performance Engineering for his brillant piece of kit!

Ok a few things still need to be worked: the first gear is the looooooooooong race gear, I am probably running a too tall final ratio (16 x 32 or 2) I had a terrible time launching the bike and the starting line was on the flat.

Next race will see me using 17 x 32 or 1.8 ratio. I suspect it will need an even shorter ratio to help pick-up.

We can now start tuning the bike, it could do with more power as it is basically using a 350 street top end.

I will also  use straight cut gears (again thanks to Ellis) and purpose-made intake discs, not my factory steels ones. this is so they fit standard disc covers (deeper than factory castings).

I am investigating having both the covers and discs coated to reduce friction… parts are getting difficult to find.

Next or first on the list will be pipes. I am running original A1R pipes modified by the previous owner but they are getting too close to the tarmac for comfort, plus I feel they are restricting the 350 motor. They do deliver but you feel that they hit really high in the rev range. Something torquier would be better.

My Smiths Tach is obviously not running at the correct ratio: full blast on a straight, it read 5’500 rpms with the bike screaming… not right.

The rear original shocks are basically dead…  I’ll keep them for collection value but need a decent pair of Hagons or Konis. Every bump on the track was transmitted directly to my spine. Ouch.

The fairing is also pretty much in the way, I have to prepare the bike to run without it, but it means I need a front fender.

Riding in the rain without one gave me a very cold shower. Got my hair parted by a jet of cold, wet and dirty blast of road muck.

Apart from all that, the rider needs some practice sessions… getting passed by (ex Swiss Mountain king riding a) bog standard T250 is quite disheartening… not being able to follow him even more! Some more room for improvement.

Gearbox is all sorted now, we just have a problem with the ignition. Using Dayle’s Starfire CDi and points interface… sounds like our set of points is faulty. It doesn’t trigger the CDi very precisely… a bit annoying when you use a micrometer!
It’s getting close to being fired.

Still running A7 specs, latest carbs, covers and discs with the exception of the pipes, which probably mean going up a couple sizes on the main jet.
A few known problems: the carbs’ filters foul the fairing, I doubt we can find shorter filters so a bit of fabbing is needed.
Looks like I have to learn aluminium welding after all. Same goes for the front fender. The one on the bike is a S-Series Kawasaki, the “original” A1R being really NLA… I’ve seen 1 in 15 years of looking for bits. A simple ally one will do AND save weight.

The development program is set, jets are in, etc. but first… get it to run.
Paint and other niceties can wait.

Smith Tach needs to go, which means I have to get the original Kaw bracket remade. I have an original Kaw Tach at the ready.

Oh, and a screen needs to be purchased, but this can wait. Will it fit an original fairing… wait and see.

Race bikes are of a different breed and everything needs to be fettled. You either love it or hate it.
I’m starting to hate it as it’s taking insane amounts of time (not to mention money, a dollar here, a Swiss Franc there, a few British Sterling Pounds over there… endless) and it’s eating time on other projects and “normal” life.

Here’s a comparison beween the various carbs found:

A1 Samurai carbs are always 22mm and require their specific covers. The calipers show the inlet stub inner diameter.

Here is the covers for them.

Now for the A7 first series of carbs. Early A7 had Vm 26 SC Mikunis, these also require the use of the correct covers.

This is the later type of covers, with the much bigger inlet stub (around 34 mm). These are the ones you want to use if building a tuned or race version.
The carbs that fit are 28 mils VM 28 SC, these have a different jetting arrangement, primary type with a shroud and round main jets.
This cover has the oil injection welded shut.
You can make the 26 carbs fit these stub by removing the phenolic bush at the inlet, but there will be a small step between the stub and carb.
Note that there is also different version of the crank cases for each of these carbs & covers!
Buyers beware! Most people selling their stuff on eBay have no idea of these differences.

My friend Hans-Peter offered to rebuild the rolling frame while I did the motor (not sure if it sucha a good idea, I haven’t had much luck mechanicking recently).

A very nice & original 1966 A1R is up for grabs at racing-motorcycles.co.uk… for a cool 15k £, a smidgen too high for my liking, specially since the bike will need complete reconditioning. But, hey, there’s only 166 of them originally manufactured and let’s not think of how many survived!
Still I find that price a bit over the top, specially if you think that a good TR3 or a Tz can be had for half of that and not need much before being launched onto the track.
Steve is your main contact here: Racing & Investment Motorcycles, with many more racing rarities for sale. He is also a genuine enthusisast and can source alot of bit for your racing bike. Check him out. At the time of this post he had avery tasty CB 92 racer and also a couple Moriwaki protos for the (now ditched) GP 125 class: cool 250cc Suzuki based Racers.

If you don’t a position ring (the half moon that keeps crank bearing into place)… it’s OK, they get lost a lot, but they need to be there.

Just use  a H1 ring, they’re the same.

Part # = 14013-1004
Part Description = POSITION RING
Model Count = 179
A1 N/A 250 SAMURAI DUAL PURPOSE 
A1R N/A 250 A1R STREET 
A1SS N/A 250 SAMURAI SS DUAL PURPOSE 
A7 N/A 350 AVENGER DUAL PURPOSE 
A7SS N/A 350 AVENGER SS DUAL PURPOSE 
H1 N/A 500 H1 MACH III STREET 
H1B 72 500 H1 MACH III STREET 
H1C 72 500 H1 MACH III STREET 
H1D 73 500 H1 MACH III STREET 
H1E 74 500 H1 MACH III STREET 
H1F 75 500 H1 MACH III STREET 
KH500-A8 76 500 KH500 STREET

“NTN still list their EC bearings as available- these have two orange plastic rings in their outer races which took up any difference in expansion between bearing outer race and crankcase. Kawasaki used them for their road racers such as H1-R, H2-R and KR750. H1-R cranks used all-roller main bearings, and later apparently switched to cranks with small main roller bearings and large main ball bearings; I have seen one such crank brand-new in the original box.
For the H1, you would require three EC6205/C3, two EC6305/C3 and one EC6305N/C3.
For the H2, three EC6206/C3, two EC6306/C3 and one EC6306N/C3.
For S series, three or five (depending on whether you have a four-bearing or six-bearing crank) EC6305/C3 and one EC6305N/C3.
For the A1/A7, three EC6305/C3 and one EC6305N/C3.
ONLY NTN make these bearings, so be sure to specify NTN when ordering from your friendly bearing supplier.
EC, by the way, stands for “Expansion Compensation”.

The roller bearings for the H1-R are the NTN ECNJ205G1/C3 and ECNJ305G1/C3, and these may also be available, but these are FILTHY expensive………”

This solves my problem of finding good enough bearings for the A1R… now where to get them?

Kawasakis of the period didn’t have matching frame/engine numbers. Engine number is usually between from 50 to 200-300 range from the frame #, although later the diffrence ranged up to ~1’500.
The motor numbers are always higher than the frame numbers, same thing applies to the Triples for example. This is due to the way they made them at the factory, when ramping up production: motors might be more complex to assemble, but actual assembly is faster.
So when assembly started, the gap between the numbers was low and went up as the year went on. Numbering didn’t stop between the change from model year to model year. The last ’71 models had a large number difference between motors and frames. The early 67 models had a very small difference in numbers, maybe due to more precise assemblies and the fact that it didn’t sell, the company wouldn’t be submerged in leftover motors.
Since there were modifications to the motors specs (more on that later), it could well be possible that Kawasaki reset the numbering at the the start-of-model-year numbering. In this case the next model year frame #, were in fact just a few up on the last motor # produced the year before, to start a new model with a “round” number. The leftover motors were probably used for under warranty exchanges.
So the difference should always be greater at the end of the year than at the start. And there SHOULD be a very very few matching numbers bike, with very early model year numbers.
Hope it makes sense…

So here’s the list: it pertains to the frame numbers only. These are from Kawasaki themselves and can be trusted.