The 125 engine uses just the
front cylinder of Franco Lambertini's modular design. It started off
with a capacity of 119.75cc later getting a slightly longer stoke,
increasing the capacity to 123cc.
The engine was fitted into
two styles of machines; the 125H, with styling similar to a Strada
and the 125KJ, which is in effect a baby Kanguru.
Producing a claimed 13.75bhp
@ 9000rpm it was above the old UK 12 bhp (9Kw) learner category power
limit for 125cc machines. As such they're quite rare bikes in the UK;
not that many people want to ride a 125 except on 'L' plates. However
a few years ago the power limit was revised to bring the UK into line
with Europe and is now 11 Kw (14.7 bhp).
As a single the engine is not
terribly well balanced, but in 125 form it doesn't so much vibrate as
tingle. It's certainly a willing performer and provides a cheap
introduction to Morinis. It has the same six speed gear cluster as
the 250, 350, and later 500 twins and apart from the lack of
provision for a rear cylinder the crankcases are the same. The major
differences are a wet clutch and that the ignition trigger is mounted
on the alternator stator plate (and is therefore a wasted spark system).
