too rich, holding back?

[1mustard]

hi all a quick one traveller 1970, sweet as a nut on idle, drive down the road, 3000rpm starts holding back/hesitating, you can slowly drive through it but i am sure its fuel, carb fault, checked all the basics, vac unit, plugs (black,too rich), points condensor etc, also it has a mechanical fuel pump in the block (new) i can't see this being too much of a problem, correct me if i am wrong, also gutless its got bottom end rumble, mains, ends, but not to bad (yet).
any advice on the fuel, the jet goes up and down smoothly seems ok, i need to get it on the gas tester to set the emissons.
any ideas?
cheers

[bmcecosse]

Is the air filter choked ? Take the element out and try without........ Also check there is some oil in the carb damper. Have you optimised the ignition timing by advancing till it pinks - and then retarding slightly ?

[1mustard]

tried all these except the timing, i am waiting on some points, condensor etc and i was going to do the timing, emissons etc then. hopefully that will sort it, but i'm not convinced it will, i'm sure its fuel, but i won't know till i tune it, i may have a quick look at the float, needle, but to be honest i have rarely had a problem with an su.
be a result if its a dodgy condensor but the points look good so i'm sure its pointing to fuel.

[bmcecosse]

Is the vacuum advance working?

[1mustard]

yes mate, had a suck on the pipe and the plate moved but only with a hard suck, i had it running and couldn't feel a hard sucking on my finger, do you reckon this could be worth a go?, i thought the same but the symptoms are more like it literally won't rev really holds back, foot down coughs and stutters then you can softly accelerate through it, but will rev perfect when stationery, its like when you have a jet blocked on a weber carb.
perhaps under load could be electrical.

[bmcecosse]

Running rich won't cause 'holding back' - quite the reverse! Sounds like advance problem to me - either faulty mech advance (what number is on the cam inside the dizzy?) - and/or vacuum advance - is the vac connection on the manifold clear? Does the piston rise and fall easily in the carb - and try 3 in 1 oil in there. Also maximise the advance till it pinks - then retard slightly.

[1mustard]

i advanced it quite a bit and it improved a little, i got my strobe on it and it is advancing, it revs but is realy flat, it is better when warmed up which makes me think fuel, what do you think?it rises and falls smoothly, i have another dizzy may be worth trying it just to see if it cancels out the dizzy.
cheers bmc to be honest i was going to pm you as you clearly know your stuff and i do respect your opinion, two minds are better than one.
cheers

[bmcecosse]

Try another dizzy by all means.