Recommissioning a '48 Rapide

[Bill Thomas]

Thanks Gary, Must admit I have never thought about it, I know what works and how it works,
I know it likes a lot of free play,
I have always worried about using too much strength on any cable, Including Brake Cables.
Cheers Bill.

 

[BigEd]

If you think about it, the exhaust valve only needs to be just cracked open to release the compression so you slacken the cable so it only just operates the mechanism.

 

[Bill Thomas]

Also if used to stop the engine, Try and get the rev's as low as poss', Just to keep everything safe.

 

[Bill Thomas]

Thanks for your replies guys. I did read the recommissioning thread, freaked out and then asked a few local bike shops but they didn't want to know. I guess there is a first time for everything and no better way to get to know the beast. It has a coil fitted so assume modified from the original magneto. I'm hoping its true that love conquers all and where there's a will there's a way.

When I was 15 I worked in a small Motor Bike shop,
The Boss told me NEVER let a Vincent in the Shop !!, He knew my Brother Ron had HRDs.
And yet after I had left His place to work on BMW BIkes in London, He phoned me up to say a Bloke had been in the shop wanting to sell a load of BITS !!
That was a GOOD day !, One and a half Bikes for I think £25 , The cases needed welding bad !,
But it was to be my L/ning rep' .

 

[PaulC]

Thanks Bill, yet to tackle that one but another question if I may. My monobloc carbs (unknown model) are each fed from the tank independently with no feed pipe between the two, hence no reserve! They have 340 main jets. Also, neither carb has a choke cable or levers. Would you have any idea why and if this could be contributing to the starting issue, alongside the sticking lifter?

 

[Bill Thomas]

Hello Paul, These are funny old bikes, No two the same !, Us old sods can't leave things alone .
Can't see why He hasn't linked the carbs with pipes, Only if He didn't have enough bits.
Easy fix, They did the Carb' outlets with twin pipes coming out, Or you can use a "T" junction, Or 2 , But will need more piping, Make sure the pipe you buy is good with this new petrol, Might be an idea to change what you have if the Bike has been laid up for years, I had an old type pipe break up once = not good , Petrol all over the rear tyre, Wondered why the Bike was going sideways, My lucky day, Stayed on !.
"Surrey cycles" have all the bit's, Or the club Spares.
I think 340 main jet is Ok, Bit big but it might be a fast Bike ?.
We did a Twin a few years ago which had Mk2 Cams in it, I think it Makes a difference , But not everybody agrees, All my Bikes have race Cams and open exhausts, I raced them and have left them the same.
Monoblocs use bigger main jet size than later Concentrics.
In the old days we all left the chokes out, Less cables and junk on the handle bars, Just tickle the carbs
for cold start, it's much safer to run a bit rich overall , So once started it's fine.
Vincents can get a bit HOT when thrashed, Or even on a Hot day, With a long uphill etc, We had a lot of trouble with low clearance pistons, Still do !!,
That's why I have always used the old Specialloids with 10 thou clearance ie racing clearance, But again other people won't agree.
I am building a bike now and I have a barrel and piston which is NOT Specialloid, Not sure I want to fit it,
Can't make up my mind ??.
Sorry, What I am trying to say is if it's a bit rich, It helps to keep it cooler.
We are also retarding the ignition a few degrees to help with this petrol.
Can you just make up a bolt or something to put in the hole where the choke cable goes ??,
So it's not sucking in air, Don't think it's a problem, But would be nice ?.
Starting from cold give them a good flooding, Till you know what it needs.
You might have trouble getting to the pilot screw on one of the carbs, They made handed ones later .
Did yu get the lifter cable off OK ?.

We run on the left tap on the tank, Right one reserve, Sitting on the Bike, More petrol that side, But there is NOT much,
So put 2 gallons in the tank and you should be OK for 100 miles, But check till you know the Bike.

 

[Bill Thomas]

https://www.vincentownersclub.co.uk/resources/1-3-16-monobloc-settings.2212/

https://www.vincentownersclub.co.uk/resources/a-modification-to-the-monobloc-pilot-adjusting-screw.2266/

https://www.vincentownersclub.co.uk/resources/setting-up-new-monobloc-carburettors.2267/

 

[Bill Thomas]

Paul, Just found my Amal book,
Monobloc 1. 1/16. main jet 240.
1. 1/8 280.
I think they are a bit on the small side, I would go up at least 2 sizes.
And I have heard of the 1. 3/16 up to 340, Like you have. What size is your Carb' ??.

Any "D" men out there, Can give us a clue ????.
Cheers Bill.

 

[Bill Thomas]

Just thinking out loud, We sometimes have trouble with the Kickstart jamming ??,
And also it can slip on the ratchet ??.
Some people have trouble for a long time, But once fixed, No trouble.

 

[PaulC]

Just thinking out loud, We sometimes have trouble with the Kickstart jamming ??,
And also it can slip on the ratchet ??.
Some people have trouble for a long time, But once fixed, No trouble.

Hi Bill,
Took off the lifter cable, oiled it well and it is a bit easier to use. I think the bike was set up as a racer but don't know the monobloc model size and suspect it is 389. They have extended end plates to make the petrol reservoirs bigger. Both carbs are on the right side of the bike. Anyway I have reconfigured the pipe lines with a "T" and hopefully it won't starve them of petrol. I think the choke cable holes have been blocked already. I think I'm getting there but yet to do my first test run, tomorrow hopefully. Thank you for your advice (I might be back, tell me if I'm becoming a pain).