Carburettor choices

vibrac

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VOC Member
WOW! a paraffin pump still available (For the name of the pink paraffin man..etc.) Do you still have two stroke mixing pumps on the forecourt? :)
 

Roslyn

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Non-VOC Member
WOW! a paraffin pump still available (For the name of the pink paraffin man..etc.) Do you still have two stroke mixing pumps on the forecourt? :)
not any more it all come in expensive 1 0o 2 litres plastic bottle and i do car boots and look out to by them cheap as with ATM (used in forks and primary drives on my bikes and if i have do take the cover off for any reason it is nice and clean no sticky oil any where), gear oil etc for and 50p to £2 depends on the amount and size in the plastic bottle and paraffin is no longer pink is blue
 

Martin Conachey

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VOC Member
During a long and tiring search to get my 1950 Rapide to start, over the past few years (20 odd!) I have:-
Had Dave Lindsley rebuild the Lucas mag. Tried - no change.
Bought and fitted a BT-H electronic may. Tried- no change, reverted to Lucas mag.
Replaced with new, carburettor needles, slides and jets to original spec.
Fitted a brand new old stock advance/retard unit.
Checked and re-checked valve and ignition timing.
It occasionally does start after ten or more kicks, going off to recover and having another kick. It may then just fire up and runs perfectly!
It's just that it is totally unreliable when it comes to starting.
I will just mention that I have a Vellocette Venom and very rarely have problems starting that.
Any suggestions please?? Perhaps different carbs?
I have recently fitted a pair of Amal Concentric 928 supplied by Burlen and modified the Feed Nozzle, What a difference. Starts first kick. Pulls like a freight train
Martin Conachey. Mem. No 22010AB
 

Hicam

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Non-VOC Member
I have recently fitted a pair of Amal Concentric 928 supplied by Burlen and modified the Feed Nozzle, What a difference. Starts first kick. Pulls like a freight train
Martin Conachey. Mem. No 22010AB
Sounds like a good solution which I may have to carry out.
I have been working on two interelated problems:-
1/ original worn carbs.
2/ crap Magneto's.
Having replaced slides, needles and jets on the carbs they are much better.
The renovated Lucas mag provides second or third kick starting from cold and the bike performs well but when the mag is hot it will not start.
A local club member is going to loan me his spare mag which will help.
I am now sorting the oil leak from beneath the dynamo where it butts up against the primary chaincase!
 

Martin Conachey

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VOC Member
Some Mags have been rebuilt using Indian made parts , the previous owner of my Rapide had spent a ton of money on his mag. When Bob Culver who built my engine a few years ago , saw it he was not at all impressed with the quality of the parts, He rebuilt mine using premium parts,
Re the carbs, a friend had carb problems with a BSA A10, He went thru all the hassle of parts changing . After a lot of time he discovered that the inner body of the Monobloc was very very worn, Solution i gave him a good monobloc of my Rapide
We sometimes forget that Carbs like Tyres are consumables , We don’t half beat ourselves up. Just spend a little money. And ride the WHEELS of it
 

Roslyn

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Non-VOC Member
Some Mags have been rebuilt using Indian made parts , the previous owner of my Rapide had spent a ton of money on his mag. When Bob Culver who built my engine a few years ago , saw it he was not at all impressed with the quality of the parts, He rebuilt mine using premium parts,
Re the carbs, a friend had carb problems with a BSA A10, He went thru all the hassle of parts changing . After a lot of time he discovered that the inner body of the Monobloc was very very worn, Solution i gave him a good monobloc of my Rapide
We sometimes forget that Carbs like Tyres are consumables , We don’t half beat ourselves up. Just spend a little money. And ride the WHEELS of it
Had same problem but a worn out pre monobloc on one of my bike so gave in and replaced it with a new monobloc as is was the cheaper option as new pre monoblocs are a lot more expensive
 

Hicam

Forum User
Non-VOC Member
Had same problem but a worn out pre monobloc on one of my bike so gave in and replaced it with a new monobloc as is was the cheaper option as new pre monoblocs are a lot more expensive
Dave Lindsley did my mag as he had rebuilt a couple more of mine which have been ok but this one isn't, unfortunately. He did it about ten years ago but I have only just fitted it. He has agreed to have a look at it for me.
I agree that the carbs are consumables and have a limited life as do many components on any motorcycle. Unfortunately, I like my bike to look original and replacing as many of the worn parts as possible on the carbs will improve them. Over £800 to replace them with new 376's isn't as attractive as just over £300 for a pair of 928 concentrics but then you have to modify the carb stubs to flange mounting. I will report back on the performance of my carbs (they may still have to be replaced!).
 

Roslyn

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Non-VOC Member
£800? more like £420 for two 376 carbs depend were you go to buy them? as for stubs I have set of Roy Harper stubs and was told by my late father and have not used them as you have move the battery carrier to fit 376 carbs
 

Roslyn

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Non-VOC Member
£800? more like £420 for two 376 carbs depend were you go to buy them? as for stubs I have set of Roy Harper stubs and was told by my late father and have not used them as you have move the battery carrier to fit 376 carbs
376 flange mounting stubs
 
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