CARBURETTORS: T he twin carb tuning does not go far enough! To ensure both sides lift together at
precisely the same time use a mirror placed against the air filter, in place of the rubber unions. l hen by
looking back from near the handlebars you can clearly see the sides. Yet another way to ensure that the
slides lift together, once you have each carb set to give even tickover, is to remove the float bowls and
main jets and watch the needles rise and fall. A much better tuning sequence is: --- (l used this on all my
racers and it is 100 per cent effective):
1.
As per booklet.
2.
Ensure that both slides totally disappear into the carb body at exactly the same time. This
ensures that "full-bore" is truly what it means. (It is possibly to do the tuning as on page? I and
yet for one slide to lag behind the other.)
3.
Close throttle and ensure that both slides lift off their stops at exactly the same time. Adjust using
the throttle stop screws. Ensure that there is cable slack at the twist grip. We now have the
situation where the sliders are in exact unison.
4.
Go for a ride and warm up the engine.
5.
Adjust the air screws to get an even tickover irrespective of the rpm.
6.
If the rpm is too high, lower both throttle stop screws the same amount, a little at a time until the
correct rpm is achieved. If the rpm is too low reverse the process.
7.
Go for another ride to cool off the engine (it would have got hotter whilst making the adjustments)
and
recheck.
I adjusted my carbs by removing the float howls and watching the needles and later had them checked
with vacuum gauges and they were dead right-so it is accurate.
The prize winning Mk Ill Roadster of Bob Slater, featured at club rally and record cover
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Summary of Contents for 850 Mk 1 1974
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