Triumph Repair: GT6 spark plugs, shaft bearings, point gap

Question
I removed my spark plugs one at a time to check the gap and found the first 5
looked the same but the 6th was noticeably wet.  Could it be not firing?  The
valves are adjusted properly and the engine seems to run smoothly.  Is this a
problem?  If so have you suggestions on where to look for a solution.

Answer
Hi Garry,
It just means there may be a problem and tests are needed.

First you need to either clean or replace the plugs and run a "Wet" and a "Dry" compression test. (be sure to hold the throttle wide open during the tests and be sure to spin the engine at least 4 or 5 revolutions)

Run the "Dry" test first. You should see about 125 to 160 PSI on each cylinder.

The "Wet" test is for a ring problem. Do the wet test right after the dry test by putting about a tablespoon of engine oil in the plug hole and run a second compression test (throttle open and 4 or 5 revs.) The wet test should not be more than 10% to 15% higher than the dry test.

If the tests show "OK" for all cylinders including #6 then you need to look at #6 plug wire and the distributor cap inside and out especially around #6 position. Also check point gap and any free play in the dist shaft bearings.

If you only cleaned the plugs keep track of the #6 plug and put it in a different cylinder. (A clean good looking plug can still be bad)

let me know,
Howard