villiers mk20

[hybridv8]

Hi all,I am in need of some help with my villiers mk20 engine,I have recently aquired this fitted to a mayfield and managed to get it running but running quite rough and would not idle,when I checked the plug it was very sooted after only a short time running so I thought I would clean the carb out, now it will start but will only run for a short time and will still not idle I have set the jet screw all the way in then backed out 2.5 turns,is there anything else I can do it seems such a simple carb I am at a loss,any help greatly appreciated.

[wristpin]

As ever, start with valves – faces, seats and gaps, then the ignition – points faces and gap, and then the carburettor. No amount of fiddling with the carb will achieve satisfactory running until the basics are right.

[andyfrost]

From your description I would be inclined to look towards your ignition/timing set-up.

Andy.

[hybridv8]

Thanks for the replies,I have had the mag off and replaced the ign lead with new and I took the points apart and cleaned them up with emery I put the mag back on and set the points to 16 thou and checked and double checked then took the head off and set the timing 3/16ths btdc and checked this twice by turning the engine over and checking when the points were just opening and replaced the spark plug with new.I havent touched the valves yet so I will go back to them and start again.

[wristpin]

I would question the wisdom of setting the points to 16thou, the top end of the recommendation of 12 to 16. I would always aim for the middle of the range as quite often the final tightening of the clamping screw will move them a fraction. If the aiming point was 14thou and they do move, you are still likely to be within range without the need for further fiddling about.

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