The Kneeslider

Doers Builders and Positive People

DIY GSXR1400f – When a 750 is Not Enough

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GSXR1400f by Martin Labonte
GSXR1400f by Martin Labonte – click to enlarge

Martin Labonte had an ’89 GSXR750. Nice enough bike, but, to Martin, as with many of us, there’s no replacement for displacement and an 1100 swap is a somewhat popular engine for the smaller Gixxer. He found one, but it didn’t work out, a “bad deal” he tells me, so he kept looking. The GSX1400 never made it here to the States, but it has quite a following across the pond, and Martin kept thinking the big inline four would be perfect for his soon to be former 750, besides, he didn’t see any 750 to 1400 swaps riding around and being unique was a plus, so the project began.

GSXR1400f by Martin Labonte
GSXR1400f by Martin Labonte

He immediately found the 1400 oilpan was too wide for the framerails so he had to modify the frame, which meant he needed an aluminum welding certification so the bike could pass the German TÜV. He took a welding course to increase his skills and he was ready to get to work. He welded up an aluminum seat, an airbox that looks just like the original, oil cooler covers and a 60mm triple clamp.

GSXR1400f by Martin Labonte
GSXR1400f frame and engine fitment

In the back, he installed a single sided swingarm from a VFR750 plus a Triumph drive and 6×17 inch Triumph wheel. With a new header and DynoJet Power Commander, the big four puts out 125 horsepower and 92 foot pounds of torque.

The swap looks clean and well done and Martin shouldn’t have to worry about seeing another one like it. The extra grunt should make for an interesting riding experience, too. Another great example of, “if they don’t sell what you want, head for the shop.” Very nice work, Martin!

GSXR1400f by Martin Labonte
GSXR1400f by Martin Labonte – work in progress – aluminum tail section

Comments

  2. This is my first comment so first off I have to say I have been checking the site almost daily since the day I came across it and I wanted to say the content and commentary are awesome, thanks for sharing Kneeslider.

    This machine is a perfect example of why this site rocks. A person with knowledge, passion and drive taking what they have and transforming it into something incredible. Who wouldn’t love a huge displacement streetfighter, especially one this unique, man I bet it howls with that pipe setup. Great work!

  3. That looks like it was a well done project and a reminder that some countries care how nicely done your work is. I’m glad I don’t have to deal with a TÜV – not because my work wouldn’t pass muster but because I can’t stand the government being in my business. I guess that’s a better way to weed out the hacks instead of death by faulty weld.

    Man, Martin must be TALL!

    -todd

    • What could I do? I had to make the welding course or it would be only something else for the living room – only show! You can be so happy that you have no TÜV!!!

      • Yes and we will try to fight the Eurocrats in the air and fight them on the beaches to stop them meddlling in our biking. Not be like the poor French who can only have 100bhp max to use.
        And bikes over 7 years old banned from cities.
        Here in England we have the SVA (single vehicle approval) for special new builds -generally unhomogulated cars. Which is nowhere as stingent as your TUV. A normal annual MOT test would suffice for your bike to be ridden here..
        Nice job on the bike!

        • There is no law in France thats says bikes have to be under 7 years to ride in the cities, My K2 GSX 1400 turned ten years old this month

  4. Good find Paul …. As if the bar ws not high enough already?

    Sheesh ………… what a build……

  6. It’s like the Spondon frame – a few years ago was a marketing authorization in Germany still possible. Now with the exhaust gas regulations – strength report (that´s the biggest prob!!!) – it is only possible if at all when you add an engine with fuel injection. Old Bandit or Gixxer engines are no longer allowed because of the carburetor…and the exhaust has to be pretty quiet!
    But you see – everyone has problems in the European Union!
    In Italy, they can only fit a different tire or other exhaust! ;-))

  7. Imagine, here in America, having to take welding courses, get certified and develop fabrication skills before building a bike so it could pass inspection! Hmmm…. maybe we’d see even more better bikes being built. Sure, the regulations in Europe are stringent, but it means there will be no cobble-jobs or backyard bodges on the roads. Personally, I’d like to know the custom bike running up my taillight was built by someone with certificates in welding and fabrication.

  9. Sure doesn’t look like the Japanese manufacturers had to pass any kind of certification tests in the 70’s

  10. WOW! what a beauty… it has the look of an impossibly big engine, like the old rat fink cartoons. Bet it runs like a scalded dog!

  12. Martin, 125 HP doesn’t seem right for a 1400cc GSXR inline 4. Can you comment on the actual HP that you’re getting. My guess would be at least 150HP and quite possibly 175HP without a great deal of effort.

    • That’s what I’ve been wondering. 125hp is no more power than a GSXR750. It must be very mildly tuned.

      • The original GSX 1400 engine has 106 hp!! . With the Devil and Shark Exhaust, Power Commander and K & N now 125 hp. Since she has very mild camshafts – with Yoshimura camshafts were possible
        150 hp/150Nm.You could also use another injection from the GSXR 1000 K1 which has a diameter of 40 currently the GSX 1400 has a diameter of 34.
        It is not a Hayabusa engine!!! Is just designed for torque / big cruiser ..

        • As said 106bhp standard, mines running yoshi cams, power commander, yoshi cyclone exhaust, & pod filters turns out 137 bhp on the dyno, the point of the 14 is the low rev high torque, there are not many sports bikes out there that can beat a well sorted 14 of the line & with a good rider they hold there own in the twisties to.,
          By the way – great build Martin.

    • Hey Andrew!

      It´s not a GSXR engine!! It´s a GSX model.. As far as I know
      not available in the U.S.

      • Thanks Martin,

        I read your comments above about it being a big torque cruiser engine and it all makes sense to me now. That must be a lot of fun to ride with all that bottom end torque! Nice looking build too!

  14. It’s the last of the line of oil air cooled engines, the cam’s are so mild that my own bike hasnt required the shim’s done in 150,000km ! They have been tuned though with high comp pistons (STD 9.5-1) cams, bore (1610) and head work to produce over 160Hp and @ 160Nm torque. The people who tune them recomend keeping the standard throttle body’s to retain the torque. A standard 1400 will beat just about any bike on the road to 100kph (60mph) but then have the competion fly past. In the real world though (not race tracks) a good 1400 rider can keep up with and beat a lot of sports bikes. An Australian super bike champion had one as his personal ride and he used to embarise a lot of sports bike riders with it. Lack of outrite horsepower is made up by fantastic torque.

    • Is torque a special kind of power? If it lacks power, I doubt there are any places on the tach where it makes more power. Max power is exactly that, throttling a motor less or spinning it less will produce less than max power. Using half the throttle of a 125 hp 750 (62.5) is still the same as using half the throttle of a 125 hp 1400 (62.5 hp).

      I’m sure these are pleasant motors and I too have been beaten by better riders on less powerful bikes. This bike is more about the excellent craftsmanship and a 125 hp 1400 is infinitely more powerful than a blown 750.

      -todd

      • Depending on your dyno/engine set up the 14 tops out at 8500 – 9000 whereas most sports bike red line at 13000 or more, fitting yoshi cams /exhaust etc makes a clean power curve right upto 9000 whereas in standard form there is a slight drop at around 4500

      • Torque and hp are mathematically related. A mildly tuned 750 may have 125HP where the OEM GSX 1400 engine has 106HP but the 1400 has probably twice the torque. As far as how that equates to actual race performance depends on the rider. I would suspect with equally talented riders the lighter more powerful bike would prevail.