13-06-2022, 10:23 PM
Ivor, Rebuilt my A10/4 engine and refurbished its Zenith 26VA, new plugs and had the same result as you are getting now.
The short story after redoing carb and distributor again was that plugs 2,3 and 4 had very low internal resistance. should be close to infinity. Brand new NGK's so took them back to supplier and got a new set. engine ran fine for about 30 minutes then no pick up on the throttle. checked the plugs and same problem. got my money back and purchased another brand.
my advice is to put back your old NGK's and see if that fixes the problem.
With NGK's in our neck of the woods in Aus/NZ, rumours of Chinese knock offs are rife. Maybe the same thing is occurring with Champions where you are.?
The simple test I did was to run the engine at idle speeds and use a long screwdriver and short out each plug to the adjacent head stud nut and see what effect it had on the engine.
For me, shorting out #1 killed the engine, where shorting out 2,3,and 4 did nothing.
Holding each HT lead to get a spark to the plug terminal doesn't show if the plug has low resistance.
The short story after redoing carb and distributor again was that plugs 2,3 and 4 had very low internal resistance. should be close to infinity. Brand new NGK's so took them back to supplier and got a new set. engine ran fine for about 30 minutes then no pick up on the throttle. checked the plugs and same problem. got my money back and purchased another brand.
my advice is to put back your old NGK's and see if that fixes the problem.
With NGK's in our neck of the woods in Aus/NZ, rumours of Chinese knock offs are rife. Maybe the same thing is occurring with Champions where you are.?
The simple test I did was to run the engine at idle speeds and use a long screwdriver and short out each plug to the adjacent head stud nut and see what effect it had on the engine.
For me, shorting out #1 killed the engine, where shorting out 2,3,and 4 did nothing.
Holding each HT lead to get a spark to the plug terminal doesn't show if the plug has low resistance.