Racing F3 & Pre 89 on the cheap. NT650 story..

**NSR143** · 31st October 2010, 10:38

In the interests of racing I got a bike for racing, the rider of this is Tyler Firn of Firn Brothers Racing.

I bought a crashed NT650 Bros bike off Trade Me for $1300, fitted a race pipe after a bit of farbrication (was booked for Trade Me but whatever!), fitted a new clutch pack (I had one hanging off a hook in the shed off a NT650 Deauville thing I used to own), got some good 2nd hand race tyres off Geoff Booth (Pro-Twin geezer of Dannevrke Suzuki), changed the oil and filter to remove particulates from the smoked clutch. We have borrowed a rear rim off Daniel and Sam de Malmanche (also racing an NT) The rear rim was a 18 and they lent a 17, strangely the bikes with the 18 rear have a 3.5inch front and the bikes with a 17 rear have a 2.5 front so worked well for us to fit a 160/120 combination. The main issue relates to the speedo being damaged causing a misfire over 5000rpm due to the anti tampering speed limiter fitted to some Jap market bikes. I searched the net for answers for this problem.

Hastings Honda have helped out with some sponsorship by the way of some discounts on parts and fitting and balancing some tyres for us.

The bike did about an hour track time yesterday and all went well. I fitted the resistor as discribed in the wiring to fix the speedo problem. Someone said it blows fuses using this method but did not explain further as to what degree of regularity so I was nervous and had a panic every time the bike came in early off the track during Saturday practice.

It's hard to race on the cheap but this is not bad so far, pity there are not more bikes like this around.

The bike is being raced today at Round 1 of the Pacific Summer Series so hopefully all will be sweet.

**puddytat** · 31st October 2010, 10:49

Awesome wee bikes mate, had one for a few years & it was doing trackdays on it that made me see the light & got me into racing.
As you'd probably know in the states theres an outfit (Hord Racing) that does everything to them that can be done & I think if I remember correctly, wring 70 odd h.p outta them. Not cheap though

Go BRO(S)

**Grumph** · 31st October 2010, 18:27

I've done several of the 650's a few years back. cams reground at Kelfords, tidy the heads, better springs on the single exhaust valve - ex Kelford again. Proper tailpipe and straight through muffler and they go like a proper bike.
For out and out race use they're limited by valve guide length as to how much lift you can use. Did a set of cams for Jim Landrebe's one which traded lift for duration.
This worked well but he used Keihin flatslides - the CV's were way outside their comfort zone...
Jim rigged up 2 calipers onto the single disc to get it to stop...another guy here dropped in an NC30 front end which is the better answer. Both bikes are still somewhere around ChCh. The NC30 front end one was out to about 700cc with 2 brothers pistons & big valves. Very nice bike.

**NSR143** · 31st October 2010, 18:39

Originally Posted by Grumph

I've done several of the 650's a few years back. cams reground at Kelfords, tidy the heads, better springs on the single exhaust valve - ex Kelford again. Proper tailpipe and straight through muffler and they go like a proper bike.
For out and out race use they're limited by valve guide length as to how much lift you can use. Did a set of cams for Jim Landrebe's one which traded lift for duration.
This worked well but he used Keihin flatslides - the CV's were way outside their comfort zone...
Jim rigged up 2 calipers onto the single disc to get it to stop...another guy here dropped in an NC30 front end which is the better answer. Both bikes are still somewhere around ChCh. The NC30 front end one was out to about 700cc with 2 brothers pistons & big valves. Very nice bike.

Thanks for that, we are limited in two ways, running F3 we cannot change the carbs and in pre 89 we can't mess with the bikes profile to much... as a fairing would be nice. Head and cam work will come at some stage hopefully.