Should I change the carb slide?

[Greybeard]

Since my recent engine work, including fitting a RR cam the engine is not quite right. At small throttle position the engine sounds like it's hunting. Full throttle is good. When stopping, at say a junction the engine has been stopping a few times. I've usually been able to drop the clutch before I come to a complete stop and got the engine to start again. I have a feeling that the throttle cut-out may be the problem. Does this sportier cam require more air?

[RoyC]

Ask Amal.

[Flashgreubon]

Hi from Cork
Well, Greybeard, i dont know if my story is relevant to yours but here it goes:

 After a full (and eventful) engine rebuilt by SRM ,my engine would idle perfectly and pull very well from 1/4 throttle upwards but would stutter mad from idle to 1/4 throttle ,making town riding a nightmare.

 Logic would suggest too small an idle jet or a smaller slide : tried a no3, no improvement and  a no4 with same result,
 Anyway after evenings of frustration, reordering of  slides, new needle and jets ,still no joy.
 Points were ok and sparks were good.

Just before heading for the sledge (but after being driven to plenty of strong drink ) I rang Chaterlea 25 in desperation, he told me of his woes with his A10 when he got it first and how it turned out to be poor quality pick up brushes.

 My top brush was perfect,and when lifted the bottom one I found a smidgeon of carbon still hanging on the  spring despite the fact that the mag had been overhauled less than a 1000 miles ago.

 Don't they say that 99 % of carburettion troubles are ignition related ?...

[duTch]

 My first thought was 'can you not just twiddle the idle mixture/slide screws' ? ..and I'm sure you have...Then I read FlashGordons final comment.....

[muskrat]

G'day GB.
Surging is usually attributed to lean mixture. Air leak at the flange, sloppy slide and air being sucked in through the top cap/cable entries. Start the bike and spray WD around the flange and top to see if it alters the idle.
The 356 cam shouldn't make much/any difference to mixture strength.
Cheers.

Ps: yep, 2:30am can't sleep!

[Greybeard]

I should have said, it's a 276, pre-monobloc carb.

[Greybeard]

5 days later and I still have not had a chance to play with the A10!

[muskrat]

G'day GB.
An old trick is to get the bike warm/hot then smear silastic around the flange and top cap/cable entry. Start bike for a minute or two then wipe off the silastic and allow to cool (overnight preferably). The silastic will be sucked in where the leak is and seal it.
Cheers