Been so good till now

[spyke]

no, camring slot is around pegs and not moving, points centre nut tight?

Sure i must be doing somthing dumb I timed this before when i built the engine and it was spot on for last 14 months?

[bsa-bill]

.Then run motor, not good so check again gone back to firing at tdc?

 forgive me if this is silly but many of us will have done this (me included) you are stetting the timing with the A/R unit wedged in advance are you re-checking the timing with the A/R unit advanced, if not tdc is about right for the timing when retarded as when the A/R unit is NOT wedged in advance

[metalflake11]

Good call Bill, Spike, manually advance the timing using the points plate bolt with the piston 5/16"btdc and let us know. The points should just be letting go of the fag paper.

[spyke]

Well i just had 8 goes on the trot at timing! and the closest i can get when all tightened is about 12/32 close but not good enough I know but will have another go when patience is restored tommorow     Buuuuuuut it still runs very poorly at tickover like its way way too rich only gets better when pilot screw is right in tight but still rich so again removed carb , squirted wd 40 with long nozzle  through pilot valve oriface and comes out of the two micro holes in carb body adjacent to slide so still clear there.
If I knew it was definately carb id go and buy one, but dont see whats happened to change the one ive had and cant afford to waste £150 .Oh for a reference carb in the toolbox

Um

[morris]

A bit of a wild shot, but have you tried to lower the main jet needle a notch (or two)?
Some time ago I was also having sooty plugs and irratic running, which improved very much when I lowered the needle.

[Motoanimal]

I keep saying it, and I'll say it again- don't forget Orabanda's excellent tip for getting timing spot on:
http://www.a7a10.net/forum/index.php/topic,6264.0.html#msg43175

[chaterlea25]

Hi Spyke,
Remove the A/R unit completely and clean both tapers with some thinners,
Set the mag and pistons ase you are doing it, assemble up theA/R unit and almost tighten the nut with your fingers, check the mag and pistons again, fit a socket or tube spanner  over the A/R nut and give the A/R unit a tap inwards, this should lock it onto the taper, then tighten the nut
Oil has probably gotton onto the tapers since you first did the timing

Have you tried the fresh petrol???

HTH
John

[muskrat]

Ah that's what I forgot to say John. The tap on the A/R before tightening the nut. I remember now mine was a bugga to get on without turning the shaft.
Cheers

[spyke]

Stuck with me 12/32 btdc which was best i can get at moment (in the week im gonna take off mag and slot the holes and retime.)

Routed around in the garage and found an old really knackered 376,  threads gone on top, snapped off idle screw, and small hole corroded in side of carb body? plus a very worn slide for good measure ,so not so good.

Botched it on the bike holding the carb top on with one hand, blanking the mystery hole with another , adjusting the pilot with another and holding the twist grip with another hang on thats 4 hands? Anyway even with all that it ran much much better than my other best carb.

So 3 last questions as i expect your all getting bored with this post although its driving me nuts.

1-Can a carb body become defective as ive transfered all the same fittings onto the other carb.
2-Has any one got a known 376 i could try before i spend my £169
3-When you slot the mag do you slot sort of horizontally or do you have to sort of slot an arc shape

Cheers Spyke

[Motoanimal]

3-When you slot the mag do you slot sort of horizontally or do you have to sort of slot an arc shape

You need to slot the mag case in a arc shape, keeping the same distance from the spindle otherwise the studs will jam in the slots as you turn it. Don't forget some stout washers to cover those slots!

[A10Boy]

Not getting bored with this at all! 

We've all been here, but one bit of advice, make sure you have set the timing correctly and are happy with it before you go making other changes or buying a carb. If you change more than one thing at a time and it still dont work you wont know where you are.