Stage 2 Mojo GT 50 Getting the GT ready for more power Brendon Watson Time to get the little Mojo GT 50 ready for some more power. The handling side of things are often the last thing addressed when people modify any wheeled mechanical device. To us it often the first item to be addressed as grip, braking, handling keep you safe & comfortable. If you are going to make it go you should also make sure it can cope with any extra accelleration, speed & fuel demands.
To be honest I've got a soft spot for the little GT50, running this one has given me an appreciation of how much scoot you are getting for under 2 grand rideaway. It's certainly not perfect but I'm happy with what I got for the money. While you can throw a whole heap of money on parts totally rebuilding the Mojo, we are concentrating on value for money or bang for buck.
Best thing you can do to just about any scooter is to replace the OEM tyres with something a bit better. Tyres are a key factor in keeping you upright so it's usually our first upgrade. The factory CST or Cheng Shin Tyres are best described as "black rubber round things to keep your rims off the road" or "rim protectors". Don't blame Mojo for this one it's quite a common tyre that even the European manufacturers commonly use to keep costs down. I went for Schwalbe Racemans as replacements which have been fitted to my Derbi GP1 250 for a few months now. Immediate improvements are in grip providing better braking and feel while braking, wet weather riding is no longer a religious experience and despite being the same sizes have a larger circumference which helps corrects the optimistic speedo a little. This extra also gives you a slighly higher top speed. Continental Twist, Pirelli Diablo & Michelin PilotSport are options if you can't get Schwalbe.
Out of the box the front & rear disc brakes do a more than adequate job of pulling up the GT50. Again it is no SR50 Aprilia but it stops very well for a budget scoot with discs bigger than those fitted to quite a few budget 125's. The stopping power is there but it can be improved by simply flushing the existing brake fluid with a high quality DOT4 brake fluid. In most budget scooters this provides much better feel & a bit more resistance to fade. Original brake pads work fine and aftermaket options are available if you want to head down that path. We haven't bothered at this stage but will go aftermarket when the originals require replacement.
One thing limiting the build of our Mojo is the existing 4.7 ltr fuel tank which is ample enough for a stock or a lightly modded 50 but once this thing is 70cc it's going to want to use more fuel meaning less range. Making a fuel tank is too expensive so we went to our parts bin, a 6.2ltr fuel tank dropped straight it and is readily available for $105 new (we have a couple of used ones too $44). Range extended.
After the fuel tank experience we became a little curious to what other parts would fit. Since this is a project scoot we thought now would be a good time to customise the look of the Mojo, a genuine fake carbon fibre front guard was mounted to the existing Mojo guard mounts to add that little bit of individuality. A Speedo with a top speed of 140km/h has also been sourced. We also added a flatter seat for better rider tuck in capability.
The rear guard was trimmed down for reduced wind drag, which combined with the removal of the rear rack made the rear end look pretty smart except for the rear indicators sticking out. Again we turned to the manufacturers of high quality genuine fake carbon fibre accessories and a set of Carbon look indicators sourced & fitted.
Actual Spent
- Schwalbe Raceman Tyres 120/70/12 front $86 & 130/70/12 Rear $90
- Used 6.2ltr Fuel Tank $44 - New $105
- Used Genuine Fake Carbon Fibre Front Guard $22 - New $66
- Used Speedo $66 - New $160
- Used Seat $55 - New $105 retrim approx 100-200
- Indicators $52
From the pictures you can readily see we are well into stage three or the engine tuning aspect. It has Gianelli Shot exhaust fitted in these photos, we've also tried the Reverse, Next & standard systems. We're also playing with the standard variator, aftermarket variators, 70cc kits, carbies (look hard you can see the choke mechanism on the 19mm Dellorto carb).
The key with tuning budget scooters is balancing performance gains with reliability. While many scooters run a variant of well known engine designs they differ greatly in quality of internal components. Just about anyone can build you a fast engine, it's doing it reliably that takes not only skill but experience. We are going to share some of this with you in part three.
published 29/10/2009 |