Of Minds and Motorcycles

"If the H1 were a lad, it would be the sort of boy you desperately hoped your daughter wouldn't bring home. Fast, noisy, dangerous - and such brilliant fun to be with." - Frank Melling, Motorcycle USA

Kawasaki S3

The story of El Citron started back in the Spring, when my friend Nathan suggested I buy his 1974 Kawasaki S3. I needed something to ride around town with for the Spring, since my only other bike at the time was in pieces - a motorcyclist never survives a Spring without a bike.

Some History

Now for those of you who aren't familiar with '70s Kawasaki triples, here's a bit of an overview:

"...Kawasaki introduced the three-cylinder Kawasaki H1 Mach III in 1969. With a claimed 60hp from its 498cc three-cylinder, two-stroke engine, it was just the thing for a power-hungry market. Suddenly, Kawasaki was no longer an also-ran; the Mach III’s 120mph top speed and 0-60 time of 4 seconds made it the king of the drag strip and the fastest production motorcycle on the market. And the market loved it." - Motorcycle Classics

Unfortunately, despite the tremendous power of the H1 - and its larger brother the H2 - the triples were notorious for having bad handling. The frame was poorly braced, and the suspension geometry was all out of whack. Additionally, the H1 had a notoriously narrow powerband that would come on unexpectedly, which had the potential to send you flying off the bike with the twist of the throttle. All of these characteristics made the H1 a seriously scary bike to ride. The triple, along with its 750cc older brother, soon became known as "the widowmaker" or the "triple with the ripple".

Although the 500cc and 750cc bikes attracted most of the attention in the media and community, Kawasaki also produced a trio of smaller triples. The 400cc S3 was produced in 1974 as an updated version of the smaller S2, and was actually known as being one of the better bikes of the family for handling. Although having ridden the S3 in its stock form myself, I find it hard to believe.

When I told my dad I was considering buying an S3, he had an immediately negative reaction. My dad rode a slew of Honda CBs back in his day, and would never have touched a two-stroke.

"If it's what I think it is, steer clear of it! They had a narrow powerband... way too dangerous!" - My dad

Back in the Spring

When Nathan first told me about his ill-tempered two-stroke companion, I was only slightly intrigued. I had actually been thinking of buying a normal run of the mill four-stroke 70s standard bike, like a CB750 or a XS650, to turn into my first cafe racer. My plans changed the first time I heard the menacing characteristic two-stroke sound of the S3; I was pretty well sold. I would describe it as an evil lawnmower - the sound of a bike that wants to kill you.

Not my bike, but yes, that's the sound. It makes my hair stand on end, mostly with terrified excitement, just listening to this video:

I got my first reality check about vintage two-strokes when I tried to ride it home from Nathan's place across town. He had warned me it wasn't running properly, and that it was bogging a bit, but I was determined to get it home. How bad could it be?

It fired, but that's about all that was easy with it. You could rev it and it would bog, then all of a sudden gaining power at 3000 rpm. I thought maybe this was just normal, as I had heard stories about the narrow powerband.

"It just needs to be run a bit," I thought.

So out onto the street I went, with only the experience of one successful kickstart under my belt. Maybe if I kept it reving high it would help? I got onto a major street and about one block further until I had to stop at a stop light and the bike died. I tried to kickstart it multiple times and it didn't work. It would fire but then bog and stall.

I pulled over to the bike lane at the side of the road and kept trying to get it going again. I was too far from Nathan's to turn back, and too stubborn to stop trying. To make matters worse, I was blowing immense amounts of smoke onto the street from the bike lane. It didn't take long before a cyclist stopped behind me and started cursing and yelling at me.

Not only was I in the bike lane, but I was also polluting; something I hear most bicyclists are very fond of.

I turned around and not-so-calmly explained that I wasn't purposefully blowing smoke in her face; the bike wouldn't start. "Oh.... that sucks," she said before abandoning me. "I also like bicycles too you know," I yelled back. Or at least I did like bicycles, before I became the environmentally destructive monster that the S3 has morphed me into.

I finally got it going and managed to get a few blocks further before reaching the bottom of a hill. "Please don't stop, please don't stop, please don't stop," I thought, before getting stuck in a long line of traffic up the hill. I eventually reached the top, pulled over, and a sportbike rider stopped to help. I explained that there was nothing really he could do, and that I just had to get a bit further before I'd be home.

Side of road

Almost calling it quits at the top of a hill

When I got home 1 hour later, I put the bike on its side, where it decided to vomit black goo all over my parking space. "It's normal," I pictured Nathan's head saying to me with a shrug.

The Problem

- Skip this section if you're not interested in techie ramblings -

The more obvious problem turned out to be fouled spark plugs. The bike had been running on one or two cylinders throughout the ride. The middle cylinder was getting a ton of two-stroke oil pumped through it without firing, hence the black goo. I changed the plugs and the bike instantly ran like a champion. It growled with an even more menacing tone, and took off with the power of a sportbike. But throughout the Spring it would foul plugs at random, leaving me stranded for the night. I decided I wasn't going to continue riding the bike, at least until I figured out what was going on.

First, I realized that the carburetors were loose on their mounts. This meant that the engine was likely getting a lean mixture from an air leak. If I had driven it harder for long, it's likely that I could have blown a piston. I fixed this problem by using silicone around the intake port to secure the carburetors. This worked briefly, until the silicone fouled one of the plugs. I pulled the plug out to find black bits lodged in the electrode.

Then, on one of my next attempts to ride the bike, the carburetors started leaking gas out all over my parking space. This happened multiple times before I eventually I realized that the gas tank was contaminated with something that was blocking the valve seat, causing gas to fill continuously through the carbs and out onto the asphalt. It turns out the tank had been coated with some kind of sealant, which was likely breaking off in chips and clogging the fuel system.

Oil Leaks

Yes, please leak more fluids onto my parking space

I also thought that the leaking oil was probably not normal. So I eventually got around to checking the oil pump to see that the banjo bolts had been stripped to hell, causing oil to leak out. I now understood why the bike was leaking fresh oil all over my parking space, in addition to the black goo coming out the exhaust. Not to mention oil wasn't being delivered properly to the cylinders, causing who knows how many problems.

Leaky Oil Pump

Who would want one of these things? So far I was having nothing but trouble from my vintage two-stroke.

The Plan

One of my favourite builds by Motohangar, based on a Suzuki GT550, also a 2-stroke

And so now we get to the current plan. I started reading as much as I could on Kawasaki triples, and especially vintage two-stroke custom builds. Inspired from some of the work, especially the Motohangar Honduki, I decided to turn my S3 into a modern sportbike with a rebuilt vintage motor and frame. Everything else was to be redone with modern components to create a kind of modern vintage two-stroke.

I have christened the bike "El Citron", in honour of its yellow paint scheme, and due to the fact that most people thought it was a lemon. I hope to prove that El Citron is not a lemon, but rather the basis for a fast fun bike with loads of character.

You can read more about my disassembly of the S3 in my satirical post: Destroying Your Ride. It's a good thing I decided to take everything apart, since most of the parts are in bad shape. Besides having a hard time finding a screw or bolt that hadn't been stripped, the bike had obviously been dropped multiple times on either side; the foot peg mount was bent inward, along with the kickstand mount, and the center stand tabs.

El Citron

What remains of El Citron, sprawled throughout the garage

With the bike disassembled completely, and strewn across the garage floor, I can now start to plan the build and customization of the bike. The plan as of now is:

1. Transplant a modern front end from an SV650 or GSX-R. I already have a front end from an SV650, which will make the swap much cheaper.

2. Perform a modern swingarm swap from a 2001 Suzuki Bandit 600. I decided on this swingarm since the pivot width is only slightly wider than on the current S3. This will require some welding, and is definitely the more challenging part of the build.

3. A solo seat. Noone is going to want to ride on the back of this thing anyway! It sounds menacing, which scares most passengers away. It also occasionally decides to spew oil on the shoes and pants of unsuspecting passengers. At least I'm used to it.

4. I haven't got that far yet. We'll have to see how the suspension modifications turn out.

Stay tuned, as usual, for updates on this build, and on my XS1100. I assure you Big Bertha hasn't been forgotten.

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