1967 wd B40

[Pauldemob]

Hi
fitted a brand new Amal carb all specked by Amal
Ran great for a while and then became hard to start and will not run with choke turned off part way. pops and bangs and general runs rough.
Cleaned out carb bowl as drain plug in bottom of float bowl was full of what looked like Aluminium  swarf from the carb. Maybe debri from being new?Never had a new carb
Ideas please

many thanks Paul

[chaz]

possibly, cant say I had problems with the new Amal's or the Wassell's Ive fitted but in engineering experience of machining ally swarf is a problem we have to deal with for train brake systems.
we give a casual blow out when machined, then after deburring, we now clean them, after this they got to plating where they are blown out again. After this its assembly,  they cant afford stoppages due to blockages as they are on a schedule for assembly and test, a fault will hold up the cell.
I should have thought they would have been cleaned as they are supposed to be machined in India and assembled in England so I would assume tested but they never smell of petrol so maybe not. without knowing the test routine after assembly we cant say.

[Pauldemob]

I guess I am going to strip it and clean it all out with carb cleaner , give it another go,
Cheers

[Greenfield]

Hi
The uneven running is probably due to a partially blocked pilot jet. Have you checked whether your petrol tank is clean and the tap filter is intact? I wouldn't have thought that the carb was the source of the crud but not impossible.

[Pauldemob]

cleaned the carb and filters, surprising nothing in the filter from the tank but fine aluminium  sludge in and around the carb float bowl.
all cleaned out ,, could it be from  wearing in of the carb.
Is it 1 1/4 turns out for mixture screw, forgot to count. just waiting for rain to stop to give it a go
thanks for help guys,.

[Csx355]

Hi Paul. What carb have you fitted? Mono or Concentric. How long did it run well for minutes or miles? What made you fit a new carb in the first place, what was it running like before? Sorry for all the questions just helps to get a picture.

[Pauldemob]

Hi
Yep i think the problem is the pilot jet as suggested, took it out again and it was solid with fine , what looks like aluminium .
Hi csx355    Put new carb on as part of rebuild its a concentric, ran for about 300 miles before it started getting rough and hard to start.

[Mike40M]

Thinking of replacing the worn Monobloc from a T110 on my wd B40.
Did you buy yours as specified by Burlen-AMAL (626/4) for the B40 Australian WD?
Seems to be a good idea to wait ordering one until you've reported yours is running well.

[Pauldemob]

Hi its is the pilot, stripped all carb , more white stuff  in jet, going to fit in line filters in fuel lines as tank is white painted. must be so small its getting past tank filters and filter in float bowl.

[Pauldemob]

Hi mike40m
go to surrey cycles they will set the carb for you.
mines a 626 /14
it has a 130 main jet, 106 needle jet,  and the jet needle is set on the middle setting.
don't get me wrong it ran fine for the first couple of months, I am convinced it all the rubbish in the carb and now I am pretty sure it from the  petrol tank.
I say go the surrey purely because  .Amal  had such poor customer service.