Securing the Axle
A loose axle is probably the single most
common cause of the chain coming off or breaking. The ‘trick’ is to
tighten the grub screws 3 times. The grubs screws have a
hardened knurl on the inner face, which will cut into the axle,
cutting an indent to secure the bearing tightly to the axle.
Tighten the grub screw, back it off, tighten again, unscrew the
grub screw and put on a blob of blue Loctite. Tighten it a final
Cleaning the Pilot Jet
A blocked pilot jet is the single most common
cause of carburettor problems on the Max. We once had a blockage
that one could apparently see through (translucent). So now
every meeting the carb cleaning procedure includes poking the top
guitar string from an electric guitar (0.27 mm) through the
pilot jets, as well as blowing them out with an air line.
Back Bleeding Brakes
This is the standard system used on a
motocross bike front brake, which has many loops in the brake line that tend to trap air.
Remove the top of the master cylinder. Fill a syringe (c.25ml
or 60ml) with brake fluid and attach it to the nipple on the
brake calliper with a 2cm length of clear silicone tubing.
Initially pull back on the plunger a couple of times to ensure
that there are no air bubbles in the silicone tubing. Open
the bleed nipple, and press the plunger on the syringe. This
forces liquid back up the system with sufficient volume and
velocity to carry any air trapped in loops right through the
Gear Oil on Rotax
Another use for a Syringe (60ml). After each
meeting, drain the oil from the timing gears. (If none comes out
of the drain plug, or it has bits in it you know you need to
check the gears). Fill a syringe with 40ml of light gear oil,
and squirt in through the breather at the top.
Paint Your Spanners
There are few things worse than not being able to find the
right spanner or allen key in an emergency. Colour coded
spanners make things a lot easier e.g. 8mm white, 10mm red, 13mm
blue, 17mm orange and so on.
Tom Robinson - Red Stripe Racing