After my friend bought his Ferret There was no power the previous owner had fitted a new carburetor, fuel tank etc so they must have had a problem and could not sort it
For example we road ran it up a long road with a small incline it would only drive in 1st gear, the traffic was backed up and I were desperate for a place to turn and finally found one to get back to his home. After the usual points, plugs condenser. I started looking further . I then checked the inlet valve clearances .Some muppet had got them totally wrong raging 0.0015 to 25 oversise and one at ).0001 barley opening. AHA road test .
Boy it had some power for a ferret . On my last ferret I came upon the same problem but the clearance was over 0.5 " over adjusted
When looking at the rockers under the rocker cover NOTE that they are INLET valves only and need to be correctly adjusted
I am sure this often happens on other military vehicles when they are messed about by unskilled people
Laurence