We will try to give some basic answers to the most frequently asked questions about these motorcycles and using them but please note our knowledge is not gospel, just a guide and help from our own personal experiences with the bikes.
Starting a Velocette is always something that we hear people say is such a massive problem, yes it can be if they are not set up correctly like any bike, however we often see people kicking these bikes like a Triumph, BSA etc and they just don’t like that. The Velocette kickstart is such a short crank, you only really get one chance at starting it from the correct position.
The way to go about it is as follows
There is a set way of adjusting the clutch and we have found that you must stick to this procedure in order to get the correct slip and drag needed for a Velocette clutch. Don’t listen to the people who say ‘the Velocette clutch is a nightmare’ I have done over 8000 miles on my MSS and there has been no need to adjust the clutch from when we first fitted it, although it has been checked it on a regular basis.
The clutch is not like the more usual single thrust rod like on most other bikes, instead it is operated by a thrust cup carrying a thrust bearing. The operation of this type of clutch is by the outward movement of this thrust through the bearing and three thrust pins against the adjustable clutch spring holder. For the clutch to become fully disengaged the plates have to complete one revolution, after which the spherically seated, self-aligning thrust bearing (There is a much more improved roller thrust bearing now which is better than the original ball bearing item) seating in the thrust cup levels the plates and frees them from the friction plates. Understandably, this is taking into account that all the moving parts are not worn and are free to move and do what they were designed for, so this following procedure is bases upon your clutch and operating parts being in good working order.
The sequence of operation
The timing figures given in the service manuals are the factory recommended settings when petrol didn’t have so much ethanol in it, so we have found that taking 1 or 2 degrees off these figures works well for our bikes, using the standard carbs for each model. Here we will give both figures for the OHV engines – all at fully advanced
MOV – Factory setting : 40 Degs BTDC. My setting : 36 Degs BTDC
MAC(IRON & ALLOY) – Factory Setting : 40 Degs BTDC. My setting : 38 Degs BTDC
MSS(IRON) – Factory Setting : 40 Degs BTDC. My setting : 38 Degs BTDC
MSS(ALLOY) – Factory Setting : 36 Degs BTDC. My setting : 35 Degs BTDC
VIPER/VENOM/SCRAMBLER – Factory Setting : 38 Degs BTDC. My setting : 37 Degs BTDC
Running Clearance : INLET – 0.006” EXHUAST – 0.008”
For Checking the valve timing : INLET – 0.053” EXHAUST – 0.052”
Now there is a vast difference in opinion regarding what oil to run in these bikes, however we would always recommend that you only use a classics type oil, i.e NOT semi-synthetic or fully synthetic modern oil. The reason being is that modern oil holds all the detritus (I love that word!) in suspension so that it can be filtered out by the cartridge filter system. But seeing as these old bikes don’t filter the oil that way, the mono grade or classics 20/40 oils let the detritus sink, therefore it gathers at the bottom of the oil tank or crankcase, so that you can clean this out when you are servicing your bike. We would also recommend fitting magnetic drain plugs, see part number B38MS in our shop, to the oil tank, crankcase, gearbox and even the primary chaincase, which again helps gather any un-wanted metal particles that might be in the lubrication system. Again these are easily cleaned when changing the oil.
We always run good quality engine oil in our bikes and when we build bikes for people, what is the point in going cheap on the only thing that keeps our engines healthy? When you balance this cost against what the bike is worth, it’s a no brainer to me, for the sake of saving £10 a year is it worth it? We change the oil in our bikes every 500 miles or so, but certainly at least once a year.
When building a wheel, whether you have the cotton reel hub or the full width hub, the off set for both the front and back wheel should be 9/16”. This is from the machined edge of the rear hub(where the brake drum bolts to) and the machined edge of the brake drum on the front hub, to the outside of the rim
Series 11 and 14 - These were found on all the MAC models and the MSS from 1955 onwards
Series 12 – These were found on the first run of swing arm MSS models until 1955 and all the Vipers, Venoms, Scramblers, and Endurance models. They were also an option on the Clubman.
Series 12R – There are two sets of gear ratios in these boxes, the close ratio and the TT ratio. These were normally fitted to the Clubman and Thruxton model but you could choose which ration you wanted. From the end of 1960 the TT ratios were fitted to the Clubman as standard.
For better information about the exact gear ratios for these boxes, see Dai Gibbinson’s excellent Velocette Technical website at
A rough guide to what carb was fitted to each model through the years
|MSS & ENDURANCE||1955-67||376/49|
|VENOM,CLUBMAN,ENDURANCE & MSS||1967-69||R930/15|
Tanks Classics now has the majority of parts needed for the swing-arm models of Velocette but also some parts for the earlier rigid and OHC models, including the following Velocette motorcycles, MSS, MAC, KSS, KTS. KTT, GTP, MOV, Venom, Viper. Thruxton, Clubman, and LE on our on-line shop. We also stock genuine Amal parts. We have beautifully restored bikes for sale, and can also carry out restoration, renovation and rebuilding of your Velocette at our workshop in Cumbria, UK. Use our Contact Us page to get in touch.