• Welcome to the forum website of the Vincent H.R.D. Owners Club.

    Should you have any questions relating to the Vincent H.R.D. Owners Club, or Vincent H.R.D. motorcycles in general, please contact Graham Smith, Online Forum Webmaster by calling 07977 001 025 or please CLICK HERE.

    You are unrecognised, and therefore, only have VERY restricted access to the many features of this forum website.

    If you have previously registered to use this forum website, you should log in now. CLICK HERE.

    If you have never registered to use this forum website before, please CLICK HERE.

Carburetor Advice

notap

Well Known and Active Forum Website User
VOC Member
I finally got my bike on the road yesterday and had a lovely 100 mile ride in the beautiful Australian sun. The bike ran okay, though the carbs have been falling apart rather rapidly, in all sorts of ways. Today, the bike hardly started and has been spluttering, and stopping as soon as it sits upright (also missing badly under load). I assume its the carbs (Amal MK1's). Ive tried to fix them but the slides are worn, the body threads are stripped, and they (like me) have seen better days. Ive ripped them apart and cleaned them several times. I think it might be best to buy a new set and keep the old ones for spares. I was hoping to get advice on the best settings for the new MK1 carbs (jets etc). I noticed the MK1 carbs come in a range from 28-32mm (not sure what this refers to and what would be best). The bike is: a 1950, Black Shadow, 8:1 pistons, BTH Mag. I am: a 1956 Average Model in all respects (average rider at average speed). Any advice would be appreciated. Rob Paton
 

john998

Well Known and Active Forum Website User
VOC Member
Hello, as the carbs you have are not the original type I would recommend that you replace them with Mikunis perhaps 30mm.
The correct 1" 1/8 type 29s are available new if you want to be more standard.
The Mk 1 Amal is not a good or long lasting carb, The Mk 2 Amal is a much better instrument if you want to stay with modern Amal.
If you go with the Mikuni can recomend Motorcarb in the UK. They will jet them up for you if you tell them what bike they are for. Regards John.
 

Bill Thomas

Well Known and Active Forum Website User
VOC Member
Hello Rob, 28to32 is the size of the hole ie the bore, 28 is nice for slow road riding, 32 is a bit big,more for speed.I can't see why it should misfire unless it is wetting the plugs, I wonder if the Mag is playing up, Good Luck Bill.
 

notap

Well Known and Active Forum Website User
VOC Member
Thanks for the advice. The MK1's on the bike are a bit of a mess. Someone removed the bowls and with a screwdriver and then repaired the bowl and body with some concoction - looks like liquid steel. They then let loose inside the carb with a what looks like the tip of a high heel shoe. BUT, I did find what had caused the sudden missing/spluttering! The little clip that holds the needle is cracked and the needle was merrily leaping from setting to setting. I only just found this tiny crack after a day of checking everything from sparkplugs to leads to tappets. Anyway, I will buy a new set of carbs as these are always going to be trouble. Perhaps I'll get MK1's, having ripped this pair apart so many times, I could probably repair ant future carb problem in the dark! Again, thanks. Rob
 

Bill Thomas

Well Known and Active Forum Website User
VOC Member
Hello Rob, Be sure to get the new carbs with the new (stay up floats), They are better for the petrol that is now sold and you can adjust the level by bending the tags. All The Best, Bill.
 

Albervin

Well Known and Active Forum Website User
VOC Member
Rob, check to see if the inlets have been enlarged before buying Carbs. The Mark 1s are far easier to tune than Mark 2s. Order some good air filters at the same time if you have not already done so, Aussie roads throw up a lot more than just dust!! You may find a pair of 930s available through the local section as I know some people have been having a play with carbs of late.
 
Warning! This thread is more than 12yrs ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.
Top