Having firmly decided to build a racing Katana for 2014’s Spa 4hour classic endurance event, I now faced the difficult bit; Thanks to 28 years of not paying any attention to the big Suzuki, I didn’t actually have a clue what I was doing!
On the other hand, I’m resourceful, have a bunch of mates that do have a clue and I’m connected to the internet. It’ll be fine. Really.
So, brilliantly, at this stage I did what everyone that wants to build a Katana wouldn’t normally do; I bought a donor bike that wasn’t a Katana.
Scottie Redmond (ex-CMM contributor) was actually on my go-to list as soon as I was back from Spa, as he’s not only akin to a cake-fuelled version of an 80’s bike Wikipedia, but also a very efficient quartermaster for a project like this; mention you’re looking for something specific bike-wise (as I had) and more often than not he’ll be back at you smartly with a way of fulfilling it.
The Newark jumble had thrown a very tidy and complete GS1100ES in his direction, which is an overseas market model the UK called the GSX1100EZ.
2 good-looking mobile phone pics and Scottie’s description of it as “sweet running” made me sit up and take notice (worth noting at this point that a bike-breakers “sweet running” and a racer’s “sweet running” are 2 entirely different things…)
Although it looks nothing like a Katana, the EZ was in the model range at the same time and shared enough of the important stuff with the Kat to be a really good donor bike. Key parts; frame and exhaust are slightly different but usable, the engine, carbs, black boxes are identical. The bike wore 2 trinkets of loveliness that made my eyes twinkle – a period Yoshimura exhaust system and an aftermarket Lockhart Oil cooler – both parts that the race bike will put to good use.
For £1,050 I didn’t think for too long and the wrong bike to start the project was purchased.
I collected it a few days later direct from the guy who’d shown it at the Jumble (Scottie is smart you see, he sells it before he’s even collected it – leaving you with the job instead…!)
Anyway, I walked around the bike, which at a brisk pace took at least several minutes; it’s a BIG motorcycle – bigger than I expected. It was so heavy I couldn’t even get it on the centre stand. I liked it, but I wasn’t seeing a racebike at this point; work to do!
The EZ started on the button, but there was a problem; it ran like a bag of shit. The tickover was all over the place, it was running on 2 or 3, and sometimes when the revs dropped, the clutch rattled so badly it sounded like the engine was about to fall apart. Being consoled with “they all do that” by the seller didn’t really cheer me up.
My enthusiasm for the purchase needed some propping up. I recycled Scottie’s words over and over in my head “sweet running” – I comforted myself with the idea that it was just having a randomly bad day after being laid up for too long, loaded it up and kept my fingers crossed.
The guys at MSG Racing in Aylesbury tune and prepare all my race bikes and are Suzuki fanatics. They usually specialise in GSX-R’s so it’s fair to say they displayed “arms-folded” curiosity as the big red bus was wheeled into the workshop. I don’t think they were thinking “race bike” either at this point.
A few litres of a top-brand’s Super-unleaded was added as much for it’s detergent properties as it’s 98 octane. I’m keen on it for cleaning up old carbs as you run the bike, which my seat of the pants feelings tell me I have managed on at least 2 bikes, including my current FZ750 road bike.
Restarting the bike was again easy, and once settled down the running was much improved. In fact, I’d even say it ran “sweetly”; I forgave Scott and booked a slot on MSG’s Dyno. Fresh fuel for the win! Interestingly, the full Yoshimura period system on the EZ looked like it was going to bark the engines tune pretty loudly, but it was actually pleasantly quiet – Spa has a 101dB static test limit, and I reckon it’ll sail through.
Now before we get up to our necks in talking bhp it’s always worth mentioning that Dynos are best used as a comparative tool for improvements made and tested by the same dyno. The numbers different ones produce do vary wildly – up to 10% is known, more is suspected in some cases.
Looking to guideline power figures I had 2 references; firstly Suzuki had claimed 111hp in 1982, and secondly Scottie had a bit of previous with “the Runt” GSX1100ET race bike a few years back. That made 100bhp in lightly breathed on trim.
Allowing for manufacturers overblown power figures, 32 years of use, an unknown amount of time of being laid up and the aforementioned dyno variability, I reckoned anything between 90 and 100bhp would suggest good things for the engine in the big red bus. Anything just under 90 I’d have to consider as ok, anything under 80 and I’d have been looking into the bottom of a beer bottle for my comfort.
2 days later and MSG rang me up with the joyous news of 94.92 bhp. Bang on target! A small glitch in the run showed up an ignition issue, possibly a coil breaking down. Every man and his dog swap out the standard items for Dyna ignition coils and Taylor leads on the big GSX, so perhaps this just proved why that’s a good idea? Anyway, that was good news, really good news.
Along with the suspect coils, the bits I didn’t expect to be using from the big red EZ were quite extensive; bodywork, wheels, forks, clocks, loom, shocks, seat, footrests; in other words, I was using the frame, the newly dyno-ratified engine, swinging arm, the oil cooler and the exhaust.
This meant I still needed lots of Katana stuff; tank, seat, bodywork for starters, plus maybe bits like clocks, fairing frames and other ancillaries.
That’s how I found myself on a popular Internet auction site looking for Katana stuff and ended up with a 750 Katana frame, tank, seat, tailpiece, forks, swingarm, shocks, rear wheel and footrests. I got all that for £149 – with Katana seats on their own going for over £100 a pop, this was that scarcest kind of deal that makes you want to run into the street and hug a stranger.
The bike had been imported as an unfinished project from New Zealand when an expat came home. Nothing was in good nick, but it was solid enough. No need to worry about the 750 frame for the 1100 engine – the difference to the 1100 is limited to just the engine mounts on the lower frame rail, which don’t even need modifying, it just needs an alternative set of engine plates made up which Steve Adams at Lucky7 just happened to have on the shelf as I mentioned it. How very nice of him!
I liked the idea of using a genuine Katana frame, so I decided I’d leave the big red bus in one piece for the moment, and that I’d use the 750 Katana frame as the starting point for the project.
So, with 1.5 bikes to now call on and lots of positive stuff relating to the parts we need from them, it was a good few weeks and not too budget busting.
We were now ready for the next stage – cutting and bracing the frame up, starting to choose some of the race parts to replace the road running gear and planning the engine tune – it needs to be spiced up into something about 20 to 30% fruitier, which has been done many times before to these big GSX motors.
Let’s have some fun!
It’s confusing; I’m building an Endurance Katana to race and yet I have found myself looking at Brake calipers from a Pan European, wheels from a Triumph Speedmaster and even headlights from an FZ750 when searching for parts. Well, I haven’t gone potty; it’s all to do with the rules.