Engine back firing and running poorly..

[Canuk]

In a previous topic, "Valve Guide Stuck" I had the head rebuilt, new guides, valves re-seated and the head skimmed. I also rebuilt the 1.25 carbs..."M" neddles and red springs, new jets etc..

I put everything back and the car started OK...I tuned the carbs as per the "Book"...on taking the car for a run, it runs aweful..lack of power, back firing...

I pulled the air filters and went thru the tune again and still the car runs bad...I lookede at the plugs and very sooty, I leaned the jets but made no difference...any ideas would be helpful..

Prior to the valve sticking the car ran fine, so I assume the timing is OK...

[Dean]

as i always been told start with the basics

most simplish and easy bit to forget

stupid question , did you reset the tappets

[Canuk]

I reset the tappets as per the BMC manual...I believe 12 thou...I just did a compression test and hitting 17oLB on all cylinders,,,Interesting Cylinder 1 and 4 had lean plugs and 2&3 had sooty plugs???

[2ramp3]

sounds like air leak get a tin of wd 40 and spray around manifold gasket and carb gaskets whilst engine is ticking over if there is an air leak when the spray is sucked in there will be a notice able rise in the engines rpm

[Canuk]

Thanks, I will try that in the morning...

[Canuk]

Well it morning and I slept on things...

It turned out the the problem was related to the distributor cap, rotor arm and 1 bad lead...I replaced the new with the old (back tracking) and found when I drove the car it ran better but still was hesitant...I pulled the plugs, I had 3 good plugs and 1 sooted up...I checked the lead and found the copper connector had broken away from the lead...Ordered a new set of leads so should be fine...I did try the WD40 but made no difference...Thanks for the help...