BUYING APRILIA’S TUONO
Take the RSV Mille, rip off the fairing and add flat bars. Good idea.
SNATCHY FUELLING
Unbalanced throttle bodies can make the transition between shut and open throttle more snatchy. It’s obvious in town. The crank inertia of a twin is much more uneven than an inline four, but balancing the bodies keeps the firing cycle smooth. It’s just an hour’s labour to do the job: £72.
SUSPENSION LINKAGE
Tuono’s suspension linkage is exposed to attack from dirt and water. This means the bearings get thrashed, seize and then break, causing the suspension to collapse and the rear wheel to jam on the undertray. I recommend checking them after 3000 miles. It’s a 15-minute job if you have an Abba stand. There’s no external grease nipple, so dismantle, lube with low melting point (LM) grease and reassemble. We make our own replacement linkages: £99 for the dog bone.
TEETH AND SPROCKETS
Tuonos are overgeared as standard. Gen 1s run 17 teeth on the front sprocket and 42 teeth at the rear. Change that to 1644. Gen 2s run 1640, so change that to 1542. No need to mess with speedo healers – the speed sensor runs from the rear brake disc bolt. 525 is the standard chain pitch, and dropping to 520 drastically reduces chain life. Renthal sprockets take a beating (3000-mile lifespan), so go for Talon instead.
RADIAL TYPE FORK
The 43mm Öhlins radial-type forks fitted to Factorys, Racings, and Limiteds have M6 pinch bolts which have a tightening torque of 812Nm. If you over-tighten them, the fork knuckle holding the axle can crack above the pinch bolts on the front edge of the knuckle. Expect to pay £500 to replace the knuckles but be prepared to wait – Öhlins’ part fulfilment times vary wildly.
SERVICING
Don’t worry about patchy histories, these engines are near bulletproof. Intervals are 5000 miles for Gen 1 bikes and 6200 for Gen 2s. Valve clearances are checked at the initial service instead of the second major. A major service is £435 and a minor is £335, including VAT and parts. Changing valve clearances is tricky – the lines marked on the cam wheels shouldn’t exactly line up and you need crank-locking tools. Fully-synthetic oils make the clutch slip, so stick to a good quality semi.
CRASH DAMAGE
In the a crash frame. gear This and is an brake automatic levers can insurer mark write-off despite that part of the frame being very strong. Owners regularly don’t inform their insure of these marks. It wouldn’t put me off a sale, but it’s a good £500 bargaining point.
CHARGING SYSTEMS
The charging systems on Sept ’05 to ’08 bikes run with a 500 watt generator and flywheel assembly. This is too powerful for the standard shunt-type reg/rec and will burn out the stator. Solution? Retrofit an ’08+ generator and flywheel assembly that’s rated to 370 watts. Retail price: £790. Fitting cost: 3hrs, £150.
CLUTCH JET
Finding neutral at standstill can be difficult on Tuonos. There are two parts to the fix. First, make sure any aftermarket clutch lever doesn’t have excess free play at the master cylinder. nd Second, change the standard 0.60 clutch jet to a 0.40 jet. The smaller 0.40 jet fed with the same oil pressure means it squirts faster onto the clutch pack. It’s simple to change: remove one 5mm Allen bolt (rhs engine above oil filter housing) and replace the jet. It’s £13.50.
COLD CRANKING AMPS
’03-’05 Tuonos came with a battery rated for 90 cold cranking amps (‘cca’). A partcharged battery doesn’t provide enough force to turn over the starter motor which, as a consequence, damages the sprag clutch. Replacing it will cost £350 including labour. Prevent damage by replacing the battery with Yuasa’s £75 TTZ14S. It’s got a 230cca rating.