Lumpy engine after crank & flywheel balance

[SambaS]

My MK3 XR3 has had some pennies spent on an engine rebuild, its a 1.6 CVH with a webber carb. Has been rebored, new pistons, lightened and balanced crank assembly and flywheel. At low speeds it always ran lumpy, like as if it was wanting to stall, that kind of feeling. I was told this was normal, after the recent head rebuild this seems to have got worse. I assume its either, the compression has effected it, or the oil I've used, certainly when the engine is cold it is less noticeable. Once the engine is warm it is quite apparent. Should I maybe use some better oil?

The car incidentally is absolutely fine flat out, but no use through towns and villages =)

[OldSkoolRS]

Going back to my Mk3 Escort days I'd also suggest checking the following:

The cambelt/timing (should be a marker on the top pulley under the cover and the pulley at the bottom has markings on it for ignition timing and one is for TDC). One 'tooth' out can make quite a difference to the running.

I'd also check the distributor is in the correct position (again there should be a small mark on the clamp/body and a 'dot' on the cylinder head to line it up to.

If all this checks out, then apart from checking the condition of the plug leads, distributor cap, rotor arm and spark plugs/gaps then as said above might be worth taking it to a carb expert for tuning/adjustment.

[Cerberus90]

How much has the flywheel been lightened?

The lighter it is the less smooth the idle will be.....isn't it?

[SambaS]

I'm unsure how light but always put the lumpy engine down to that work having been done, it's a very responsive engine, could the wrong oil not be causing this problem? its worse since the head rebuild when the head had to be skimmed. guess i will have to live with it, only became a problem this year as i drive it every day because the Talbot needed so much work for the MOT!!