2011 at the Hammond Barn

[Alex Blair (RIP)]

Originally Posted by Bob Carriere

Cylinder balance test.....compression test..... and yes I have a gauge...

Will also re check the plugs to see if one is not firing.... they were very black when we cleaned them up just before Xmas.... and running smooth at the time.....
That would be your timing and bad gas probably..

When I think about it..... it is almost as if one cylinder was dragging... a dead weight........causing the engine to vibrate..... don't think it is a valve but will probably remove the valve cover..... look at it while running.... re-check valve adjustments.... verify all electrical connections.....

Above all will make sure it is warmed up sufficiently...... will cover the rad opening....

Bob..Do your compression test first and it could be a plug or a thousand other things but at least a compression test will give you a general picture of the engine condition..
But a cracked or broken piston skirt is a possible culprit..
Take the valve cover off and roll it over on the starter to see if the push rods aren't changing hole..that will be a start too..and eliminate stuck valves..roll it over by hand with the plugs out when you are doing your compression test.