Sunday, 5 February 2017

Hundred Quid Hacks: Benelli 250 Roadster


Back in '74 Benelli were trying to grab a share of the lucrative 250 market with a quite neat two stroke twin. The engine design was similar to the Yam or Suzuki 250 twin, with two important differences. The Benelli engine looked far better but it didn't have direct oil injection.

It was back to the good old days of Bantams and Francis Barnetts, with the oil mixed in with the petrol. This hit and miss lubrication led to either large quantities of blue smoke out of the exhaust or an overheated engine that was prone to seizing, depending on just how much oil was thrown in the petrol tank.

Despite the primitive lubrication, the engine produced enough power to get the bike up to a fairly credible 90mph, at a time when a lot of its more sophisticated rivals were hard pressed to get past 80mph. There was even some power at the bottom end of the rev range, although below two and a half grand the engine tended to stall. A little higher up the rev range the bike could potter along between 50 and 70mph without any problems.

Past seven grand the motor really took off and was almost as vicious as an early Kawa 250. Fortunately, it showed none of the handling nastiness of the Kawa triple. The bike had stiff suspension when new, that keeps its precision over the years. Coupled with a rigid frame, the Benelli leads the 250 pack, having more feedback than the SuperDream, although it's not so pleasant over bumpy roads.

Until 1979 a TLS drum took care of the braking with plenty of feel and enough power to make some Jap discs look silly. Front shoes go for 14000 miles, while rear SLS shoes last for around 20000 miles. The later disc brake was also quite useful and even worked well in the wet. Pads lasted for 7500 miles.

Overall, the Benelli had a sharp feel that would have made it class leader if it were not for mechanical and electrical problems.

The electrics suffered from junk switches, dodgy wiring and alternators that like to burn out. The solution is to throw away the stock wires, switches and rectifiers, using better quality stuff from the breakers. Most used bikes should have been modified by now. The indicators either fall off or stop working, the lights would shame a pushbike and the horn is dangerously inadequate. with renovated electrics the alternator stops burning out.

The engine can last for 25000 miles when it needs a rebore and new crankshaft. Engines can expire much earlier if they are thrashed and ignltlon timing is neglected. Clutches are a little dodgy, start slipping or fall apart - but they make a nasty ringing noise just before they expire, so it's easy to check out. Rear tyres last for 12000 miles, front tyres go for 16000 miles. Chains last quite well at fifteen grand for the cheapest variety.

The classic looks can disappear after a couple of years when the paint and chrome decide to leave without permission. Exhausts last for four to five years, there are no expansion chambers available and few tuning goodies. Economy can be quite good, with 60mpg available without very much right hand restraint. Really screwing the bike along will lower that figure to 40mpg.

Spares are rare and more expensive than Jap stuff. The best bet is to try to find a non-runner as a cheap source of spares. There was even a Moto Guzzi version but this was very rare and costs a little more.

Expect to pay between £25 and £50 for a nonrunner, and up to £100 for something that runs reasonably well. Really good bikes are now very rare, they were mostly ridden into the ground and chucked away.

The Benelli has great potential as a cheapo hack - it has a decent chassis. good looks and a powerful motor. It's just a matter of taking care of its two-stroke habits.

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