Metal Mule Bash Plate

From: Metal Mule
Price: £94.00
Contact: 01273 842094
Web: www.metalmule.com

This thick aluminium plate could well be called a 'sump-guard',
if it weren't for the fact the XT660R is a dry-sump, oil-in-
the-frame design... so I'll call it a 'bash plate' because it gets
bashed instead of the underside of the engine. Just as with
the exhaust system from the same company, this was an
indispensable modification for our bikes and the plate and
pipe should be seen as an essential pairing for off-roaders.

Many, many times we ran out of ground clearance when
riding through rock fields in the Himalaya and when hacking
through Romanian forests. There have been some huge,
gut-churning bashes and my plate now pretty much
conforms to the underside of the engine it's been
protecting. There is no chance the engine cases - and
especially the water pump-housing - would have survived
without this modification.

The plate now has several fractures (it should be understood
these were prototypes and Metal Mule say they'll use thicker
material for future production), but considering all the vibes',
miles, crashes and bashes, it has done very well to still be
there and doing its job. Without these we would still be
sitting in Romania somewhere, waiting for new engine cases
to arrive, before beginning a huge engine-rebuilding job.
Damon

Metal Mule Two-Into-One Exhaust

From: Metal Mule
Price: £319.99
Contact: 01273 842094
Web: www.metalmule.com

To do any kind of serious off-roading with the Yamaha
XT660R's standard exhaust system in place is pretty much
impossible. Running under the engine, the pipes severely
limit ground clearance and would simply be torn asunder by
rocks and major potholes. The answer to giving the XT
some serious off-road credibility is to fit this exhaust made
by Scorpion in conjunction with Metal Mule, who also
supplied our luggage systems.

On the rolling road dynamometer the change from the
standard twin-exhaust/catalyser set-up meant the loss of a
horsepower or two at certain revs and a little less crisp pick-
up at the bottom of the rev-range, even when the fuel
injection was tuned using a Dynojet Power Commander and
Lambda sensor. I'm sure this could have been regained if
we'd detached the silencer's baffle (removable with an Allen
key), but we didn't want the extra noise this would entail.
Even with the baffle in, this exhaust sounds way fruitier than
standard, but does pop and bang a lot on the overrun.

The slight loss of poke and missfires are, however, more than offset by the
fact we simply could not have done this trip, or scaled the
high mountains, without fitting this exhaust. No way. And a
saving of nearly 10kg from the extremities of the bikes'
chassis has also greatly improved manoeuvrability.

Looks-wise the stainless pipe has also turned the bike from
a road softy to a mug-plugging thug. The finish has stood
up really well and we are hugely chuffed with the overall
performance. If you're fitting this pipe for road use, then it's
a simple, 20-minute job to change; if you're going to use
the XT on the rough, however, then you're also going to
need another 20 minutes to bung on a bash plate...
Damon