The Knowledge - Velocette Owners Club

when you swing your boot (and the rest of your body) downwards. My Venom was always a first time
starter, until during an enforced lay of I completely forgot to hold the brake lever, it became a pain to
start. When I remembered to hold the brake lever again it started first kick. Finally flooding, a lot of
individuals drown the carbs rather than flood it. Try lifting your finger off the tickler immediately you see
first signs of petrol emerging
#1645 I too am a first time Velo owner (though unable to claim a bus pass for many years yet!). I have
a 1953 Alloy engined rigid MAC. The best way I have found to start it is to 1. Turn the fuel on. 2. Flood
the carbs. 3. Close the air leaver fully 4. Gently turn the engine over with the Kickstart until it comes
onto compression, 5. Allow the kickstart to return to the top of its stroke 6. Pull the decompressor. 7.
Gently kick the kickstarter until it is at the bottom of its stroke. 8. Let the kickstart return to it upright
position. 9. Kick as hard as you can blipping the throttle as you do it. It usually needs between 1 and 3
kicks to start. For some reason contrary to the other reports I have read here I have never got it to start
without flooding the carbs.
L #1742 After much searching have just acquired 1968 Thruxton with one previous owner from
new, alas now deceased. Only 36K certified miles from new and meticulous documentation. It starts ok
but will not run cleanly without cutting, coughing and refusing to rev properly most of the time. Vibration
also seems excessive. Mag/points are fine, timing is correct and plug (NGK) is new. GP carbs is on
recommended settings for needle/slide although slide does look a little worn. Surely a carbs overhaul is
not warranted at this mileage?. Compression is good and records show recent Seymour bottom end
rebuild. I am using an octane booster. Clearly, consultation with previous owner is not possible, but I
doubt he would have accepted such poor running. I would appreciate guidance on how to proceed
logically, apart from selling it quickly for a profit!
#1743 Obvious things first (as I found with mine when I bought it after it had stood unused for a few
years).
Take the carbs apart and make sure all the jets are clear of evaporated residue. New petrol.
Put on a new HT lead (but not a resistor cap). You say it doesn't run properly "most of the time". If it
runs well sometimes I would think around bad electrical connections. I had a badly crimped LT feed at
the coil which wasn't obvious because it was under an insulated crimp. Misfires/cutting out until I found
it. If it starts well but misfires when hot, what about insulation between the cylinder and the carbs? or
faulty coil? Sorry if these are too obvious and you've tried them, but if it's starting well I wouldn't have
thought it was too serious a problem. The only concern I'd have would be why it had needed a bottom
end rebuild after only 36k miles.
#1752 Resleeve the carbs. GP slides wear at an alarming rate. Mine was consuming a new slide per
year until I took the most recently worn out slide and the carbs to a carbs resleever near Sydney
Australia in 1982 and it came back with what appears to be a SS sleeve on the slide and a good fit in
the body. I then set it up as per the book (except some versions of the book say No3 slide and it
definitely has to be No4 to run crisp and clean on the midrange) and didn't have to touch it until last
year when I couldn't get a sensible static float level after an engine overhaul. That problem is being
addressed using a Keihin float needle and seat conversion screwed into the original matchbox float
chamber seat (as written up by VOCNA Pres Cory Padula in a recent FTW article). One other problem I
now have, which doesn't appear to be implicated with your VMT, is excessive wear of the cam ring
housing of the K1FC mag. There is so much slop after many years trouble free running, that poor Ol'
Faithful ended the Cape to Cape Grape Rally here in Western Australia with the cam ring supported
between a couple of beer can shims to provide some semblance of a consistent points gap and hence
a steady advance setting. Tried another cam ring but it was just as sloppy so the wear is definitely in
the housing, as you would expect. Took some tracking down but eventually got to the crux of the
problem. However two months later, the beer can remedy lives on. So, don't give up in despair, don't
sell it for a profit, just keep tinkering and using the beast until you develop a deep and meaningful
understanding and you should find it becomes the easiest starting of Velos which defies the Classic
motorcycle press generated image of being only suitable for hairy chested musclemen. If it won't fire by
the second kick after a generous tickle (very hard to get at unless you can lift the rear of the tank
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