Misc: Ignition/Mag-Dynos Series A Comet recommissioning

[AndrewM]

I'm in the process of recommissioning my new (to me) 1936 Series A Comet, previously owned by Paul and Alex Champion. It has a Miller Mag-Dyno. I have a few simple questions.

1. The Series A 1935 Manual specifies a timing value of 42 degrees or 7/16", as does "Back to A". Is this the right value for use with modern fuels, or can it be set to a lower value?

2. A lot of the rubber components have hardened up or perished. Most of these I can replace easily, but I'm not sure where top find replacement tank mounting rubbers. Can anyone suggest a suitable supplier of the rubber mounting discs?

3. I've done a good Google search but haven't found a supplier for a suitable throttle cable (approx 32" outer, with ends suitable for an AMAL type 16 throttle and an AMAL 89/11 carburettor). Any suggestions, or should I get a custom one from JJcables?

4. Are there any alternatives to the Avon Speedmaster 20 x 3.00 front tyre, which seem to be in very short supply in Australia?

5. How far should I fill the oil tank from the top? I've filled it up to the bottom of the oil filter so far.

6. The handlebars on the bike are 24 1/2" long, which seems short. Have they been cut down or is this the original length?

7. I have some pre-war HRD logos for the tank sides (i.e. no white outline) from Classic Transfers, however these are vinyls rather than traditional transfers. Are there any sources for the correct pre-war logos as transfers rather than vinyl?

 

[chankly bore]

A couple of suggestions: Although my experience is with "C" series machines, similar pre-war designs such as Velocettes now retard their ignition about 2 or 3 degrees. Rubber, except for tyres, can be restored with Wintergreen oil- search for You-tube clips online. Franc. Trento at Eurobrit usually has 3.00 x 20 tyres. Drain the crankcases into a clean container before checking the oil level! 3 1/2 pints then go in the tank. The machine will always "wet sump" without regular use. It sounds as if your handlebars are a bit short, perhaps an "A" owner can get a tape measure out. You might have a go at making your own cables; a lot of information on doing this is on various Forums.

 

[bmetcalf]

I thought gear pumps were better with sumping.

 

[chankly bore]

Certainly good when new, Bruce. But I have a friend in Yorkshire who checked his oil tank (nearly empty) then wondered why his bike wouldn't kick over. His was an "A" single. Even my Honda GB500 wet sumps a bit.

 

[AndrewM]

I've already drained and replenished engine and chaincase oil. When the bike arrived in Australia after a 4 month trip from the UK, the oil tank was completely empty and the sump was full, probably about 3 1/2 pints!

Thanks for the suggestion about wintergreen oil, I've ordered some and have had a look at some of the YouTube videos, pretty impressive results, particularly this one:

I'm very keen to try this on the tank kneepads which are very hard and inflexible.

I've also ordered some new tank mount rubbers from the AJS/Matchless owners club, these are very close to the right diameter for the Series A and just need to be bored out a bit to fit the larger Series A tank bolts.

Simon Dinsdale has already mentioned to me that his handlebars measure 27" on the bike, so I will work to that figure unless someone can give me a definitive measurement for the bare bars.

 

[rapide049]

A couple of suggestions: Although my experience is with "C" series machines, similar pre-war designs such as Velocettes now retard their ignition about 2 or 3 degrees. Rubber, except for tyres, can be restored with Wintergreen oil- search for You-tube clips online. Franc. Trento at Eurobrit usually has 3.00 x 20 tyres. Drain the crankcases into a clean container before checking the oil level! 3 1/2 pints then go in the tank. The machine will always "wet sump" without regular use. It sounds as if your handlebars are a bit short, perhaps an "A" owner can get a tape measure out. You might have a go at making your own cables; a lot of information on doing this is on various Forums.

Check on the Tyre that it is for Highway use , most I've seen say Not for Hway use , and the tread separating , Have a Crash and the Insurance company , gives you a wide birth

 

[Flyinglow]

Hi,
I measured my Handlebars last night and they are also 24 1/2" in width.

"6. The handlebars on the bike are 24 1/2" long, which seems short. Have they been cut down or is this the original length?"

 

[AndrewM]

Hi,
I measured my Handlebars last night and they are also 24 1/2" in width.

"6. The handlebars on the bike are 24 1/2" long, which seems short. Have they been cut down or is this the original length?"

Thanks for measuring. Which year is your bike?

 

[Flyinglow]

Andrew,
1936
Colin

 

[Marvel]

Andrew,
1936
Colin

That’s an early one.