Thread: Try and work this one out

Have you tried a new distributer cap? My old 2A many years ago developed a miss and the cap had tracked. The NRMA serviceman got me going by carving out the track on the inside of the cap with a pocket knife and then painting the track with acetone and drying it. Worked like a treat and although I bought a new cap I never fitted it as the old one never gave any more trouble. Hope this helps. Jim

All the ignition parts look fairly new. Had already checked the cap for cracks, so sorry it is not that.

CC

valve issue, check the clearances, overfuelling from the carby (which may mean you also have a manifold leak that blending #1+2 down the the right mix) and plug break down.

swap the leads and plug positions and combos and see what that does for you...

you should also try rotating the cap 180 to make sure that its not tracking on the cap.

For what it costs I would be changing the condensor on the dizzy too.

Several suggestions -

Air cleaner - take the top off and see how blocked up the pipe down the centre is - this does not often get cleaned and can build up thick deposits if operated in dusty conditions. Removing the aircleaner should not make a perceptible difference - if it does, it suggests you are already running too rich.

Spark plug leads - for 3& 4 in particular, remove the leads and inspect the ends - try swapping to different cylinders to see if the problem moves. I think this is the most likely problem, even if they look new. (the extra spark gap, as you found, can often compensate for other faults)

Carburetter - assuming it is a Zenith, check that the top casting is not warped. If it is, it can be ground flat using fine wet & dry on plate glass or other flat surface.

As suggested, the condenser is a potential culprit, particularly if the points needed attention. Note that you should NEVER use wet and dry on points as it will greatly shorten their life. Always use a steel file. (actually, it is usually better to replace them)

John

Originally Posted by JDNSW

Several suggestions -

Spark plug leads - for 3& 4 in particular, remove the leads and inspect the ends - try swapping to different cylinders to see if the problem moves. I think this is the most likely problem, even if they look new. (the extra spark gap, as you found, can often compensate for other faults)

John

Did this and no change to which cyinders were firing

Originally Posted by Blknight.aus

valve issue, check the clearances, overfuelling from the carby (which may mean you also have a manifold leak that blending #1+2 down the the right mix) and plug break down.

swap the leads and plug positions and combos and see what that does for you...

you should also try rotating the cap 180 to make sure that its not tracking on the cap.

Can't rotate the cap as it has a semicircular cutout on one side where the ground wire from the coil attatches.

When i swapped the plugs from 1 & 2 to 3 & 4 the problem moved. So it seems that both the 3&4 plugs where the problem.

Will have to fit some new ones to confirm this.

CC

Reminds me of a problem I've had. What it ended up being in my case was the bush that held the main shaft in the distributer was worn. Tended to make the dwell erratic as the shaft wobbled instead of spinning true. Took a long time to figure out as some days it ran great and some days not.

Put 4 new Bosch WR7DC plugs in and problem solvered. Seems strange to me though for 2 plugs to go simultaniously. 1 I could reason, but 2 together is a little odd. I will update further if any problems crop up.

Thank-you all for your help. It may not have been the problem this time, but the reference is now there to check those things in the future.

CC