The Knowledge - Velocette Owners Club

L #4164 Does any one have the specifications for ramp height for the engine shock absorber and
sprocket? If assembled without the spring should there be room for the two ramps to turn over the
peaks? mine can and has about 25 thou clearance as well. I believe this unit to be the cause of my
"clutch slip". Everything seems to be in order with other used items I and my friend have to hand. Can
any one shed some light on this assembly? Has anyone had their unit fail. I’ve heard about broken
springs but mine is intact though again I don’t know what the free length should be. I stripped the clutch
down and found the outer friction plate tangs were fouling the clutch cover plate, (new bonded plates
used)I straightened the tangs and reassembled with confidence. Ran the bike without the outer
chaincase and found that it seems to be the shock absorber is spinning at mid revs on full throttle. At
this engine speed you don’t get the machine gun noise which is why the clutch became prime suspect
in the first place. Your experiences will be appreciated.
#4166 I don't believe that the ramps should be able to clear each other. Sounds like your drive side
shaft is pulling out of the flywheel, a common failure corrected by installation of a 'nail head' shaft.
#4167 I'm not sure, but I don't think it matters... if the spring breaks it will still be too wide for the ramps
to pass each other. I had the spring break once on my Thruxton.. at low throttle openings it made an
awful racket and vibrated a lot, but once opened up things smoothed out. Fortunately only 15 miles
from home and I had a spare spring. Had the 'nail head' mod done by Dodkins when my big end went
some years ago as a precaution. Apparently the old shaft had pulled out some 20 thou or so.
#4172 The factory drawing show the ramp height to be 0.250" +/- .010" above the face, or 0.406"
trough to peak. I am referring to the shock absorber - the sprocket from peak to face is 0.375". From
peak to trough on the sprocket is 0.406". The factory drawing show the ramp height to be 0.250" +/-
.010" above the face, or 0.406" trough to peak.
#4168 Can't be that the shaft is pulling out, I had the flanged mainshaft fitted. Checked the free length
against one of the original shafts and it appears about the same, well within a few thou. So does if it
rides over the peaks like mine., is it worn? or has the spring suddenly lost it's temper?
#4179 I have experienced shock absorber clutch slip, the symptoms of which where not so much
machine gun as gear teeth stripping noise. my problem was caused by drive side main shaft slowly
eating its way though n/side flywheel causing extra clearance in shock absorber assy. The engine ran
well still!! the way to check is looking down onto big end, both end of main shafts should be flush with
inside faces of flywheels, my drive side one was 3 to 4mm below.
L #4479 Hello group, is there anybody who has used a carillo rod in a venom/viper engine? I'm
just in the process of lifting a venom engine to it's next tuning level and as the con rod seems to be
damaged after 90k miles of (hard?) service it might be worth a try. However, there is no Velo rod in the
Carillo catalogue but I remember somebody mentioned to use one in his (racing?) engine. Any
information appreciated.
#4480 Still got one in my racing Venom, contact Nick Payton and he can identify/ supply it.
L #4723 Does anyone known what the right size crankshaft oil jet is for a Venom with the early
type crankshaft fitted? There seem to be 2 different bore dia. in my collection of parts. One is bored
approx. 2.3 mm and the other about 3.3 mm. Which one to use?
#4743 0.078" with a tolerance of +0.003
L # 6353 I am in the process of rebuilding an old MOV engine, and needed to replace the main
bearings (Both roller bearings). I removed the inner races by teasing out the rollers, lifting off the cage,
and slotting a large open ended spanner over the roller channel, placing a fulcrum in the form of a 3/8
stud under the spanner as close to the bearing as possible, and whacking the spanner. Both came
straight off a lot quicker and easier than grinding through them as the last time I did this operation. ( I
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