BSA Owners' Club Forum

The BSA Workshop => Singles => Topic started by: Pauldemob on 15 May, 2017, 22:06:18

Title: WD B40 New Amal carb
Post by: Pauldemob on 15 May, 2017, 22:06:18
Hi I am new to site, but could really do with any help
I have rebuilt my 1967 WD B40.
purchased a new premier Amal 626 carb, which was set and jetted by Amal, along with one of their cone air filters
The bike starts well on the choke and warms up so choke is off.
The problem is once the bike gets hot it will not tick over, stalls and is hard to start.
Trying to reset the pilot jet and tick over ends up with the engine racing and cutting out.
I have tried running the bike stopping and adjusting pilot and tick numerous times
I have checked timing and valves several times, new points and condenser, bike has new coil and wiring, battery . It runs on a power box instead of rectifier and zenor.
I am not new to classic bikes , but first time with the  new Amal carb.
Contacted Amal, they suggested bigger pilot,  this did not help the problem
My day bike is a 1987 R100Rt BMW and I can get that ticking over down to 800rpm without any problem.

Advice please before I send it back to Amal and rebuild the old tired one it ran on before.
Title: Re: WD B40 New Amal carb
Post by: hubcap on 15 May, 2017, 22:48:37
hi paul try the air screw it should be one & a halve turns out..bert..
Title: Re: WD B40 New Amal carb
Post by: Pauldemob on 05 June, 2017, 13:39:09
Hi just an update on my new amal carb issues
Returned it to Amal only to find they had supplied it with 2 stroke needle and jets.
Just got it back, bike starts first kick and tick over lovely until bike gets hot . then it will not tickover and hard to start.
anyone had experiance of carb over heating and causing problems like this 
Its a new coil , but could it be that when it gets hot, as I have had one fail in the passed when it got hot.
Any help please
Title: Re: WD B40 New Amal carb
Post by: TIGER on 06 June, 2017, 10:10:55
Hi Although you have replaced the condenser I have experienced a number of faulty NEW condensers.
Because your bike is giving same fault on two carb. Set ups it points to electrical problem !
I would try another condenser.
You could use a non standard external condenser for a static trial.
Title: Re: WD B40 New Amal carb
Post by: Pauldemob on 13 June, 2017, 12:53:59
Hi all just as a final
I sorted the problem.
The carb was overheating and boiling the fuel, spacer I made from aluminium was transmitting the heat from the head.
Purchased a 12 mm fiber spacer from surrey cycles. Took bike out  last night, runs a treat and finally I can set the carb up for tick over.
 The moral to my problem is so don't use nice shiny aluminium spacers on your carb without a heat proof spacer
thanks for your help