Nothing is sacrelgio at Casa del Firko. If it fits, its on there.
Actually, the only thing Bultaco about that tank is what's written on it. The tank is a universal model made by Wassell for any number of trials bikes, including my Maico (if it fits, we've yet to do the trial fit.)
And what did you do to make that thing 'trials-worthy' ? Tiny carb, lower exhaust port
Shitloads Tony....but I must confess that I'm not the genius responsible. Les Richters came upon the bike through his Mainly Maico business and knowing my love of the weird and quirky offered it to me. Apparently the bike originated in the Tamworth, NSW area back in the late seventies. A bit of research has uncovered that it appeared at a couple of open trials during that time, caused a bit of interest and then promply disappeared until Les got it from a bloke who'd picked it up at an auction.
I've dismantled the bike down to every last nut and bolt to see what had been done and I found that a lot of thought and some pretty amazing engineering has gone into it. The bike started life as a '73 MC250 motocrosser. The frame has been extensively modified to the point that it's hardly recognisable as a Maico MX unit, The swingarm has been shortened 6", the rake bought in to 25 degrees, and all superflous brackets and gizmos removed. Standard forks and front wheel are used and the rear wheel is an alloy hubbed AW version.
The engine is where the builder of this bike shows his true genius. The barrel has been blue printed and fitted with a welded on reed cage that's so well done it appears standard. A 24mm Mikuni is used along with a special trials style exhaust system to produce more torque. The transmission is fully custom made featuring suitable trials ratios and the primary drive ratio is altered to slow the engine revs down for "plonkability". The clutch is a Yamaha style iten with conventional springs instead of the standard Belville washer setup.
The bike featured a CR250M Honda tank and crappy plastic when I got it O then fitted the narrow fibreglass Maico tank and a Maier rear and Pacifico front fenders. It now has a Pacifico Honda CR125m plastic replica tank, Falk trials front fender and still the Maier rear. I'm still not happy with its looks so I'll now fit the above alloy job. I've cridden the bike a number of times and it works a treat. It took me a while to sort the jetting but now it ticks away on idle like a sewing machine. The grear ratios are well spaced with first second and third being pretty close and a gap to fourth for transport sections. I'm not much of a trials rider but to me the bike handles very well at trials speeds and turns on a zac. It pulls smoothly from the bottom and seems to be able to climb anything you can throw at it. John Boag and a competitive trials rider rode it at CD6 and both reported just how good the bike is. Boagy rode the enduro course and trials course until it ran out of petrol....I couldn't get him off it.
I'd like a serious trials rider to try it out at a twinshock meeting sometime in the near future. I'd like some real feedback on what needs to be done (
if anything) to make it competitive in twinshock trials.
Compare the stock Maico frame to the modified trials frame. 
The bike when I first got it.
