Lumpy idle?

After suspecting my valve clearances were off because it sounded really tappy i adjusted them and it now runs much better but I had to adjust the idle screw on the carb because it idled too low and it now stalls really easily and jumps around on idle a bit and needs choke till its fully warmed up to idle at the correct rpm

What could cause this lumpy idle?

Cheers,
Matt

the mixture on the carb might need to be adjusted (if haven't done already) as well if the idle on there has been adjusted? when doing my timing I had to adjust both together until it idled and ran correctly

Yeah I made it leaner because there is some carbon build up on the spark plugs but have never been good at adjusting the carb, it has also always done this thing where on idle every minute or so it would drop idle and not stall but almost stall which ive never managed to find a cause to!

yeah make sure it's not too lean though! does the exhaust pop at all when under load going down a hill or anything? I've never been good at it either, luckily got a mate who's pretty good with carbs so he helped with mine, lumpy idles are often caused by air leaks too tho, common places being under the carb and vacuum lines (but I'm guessing you know all that), or a fuel pump that's on it's way out? or maybe something electrical, your ht leads alright not arching anywhere?

I had a right nightmare with mine, couldn't get the timing right, then noticed whoever last did the cam timing had done it a notch out so sorted all that and eventually (after a lot of head scratching) got it running alright, then couple weeks later gets written off by some jack a**…   

Yeah it seems to run fine if not great when driving it's just when it's not quite up to temp it doesn't like idling which coincided with the valve yiming , I've check all vacuum lines for leaks and the carb flange is fairly new and not leaking, the fuel pump is quite old but last time I tried to change it the new line was worse than the original!

Might try the timing as I had some expensive engine work done last summer and they supposedly set the vavle clearances but they have been noisey ever since until last weekend when I set them properly! So who knows what they forgot to do if a simple job like that wasn't done right  
Oh no    I use mine daily so my chances of someone writing it off a high and I couldn't ythink of anything worse  

I did some more adjustment of the valves yesterday and put the idle up a bit more and it seems to be better but it still stalls fairly easily and occasionally dips on idle every now-and-then