Sorry this is not about 50s or even 4-strokes but thought some of you guys might be able to help with this problem im having.
My 00 KTM 250sx is running a little rich and i thought i was fouling plugs until i realised that the spark plug gap is closing. my bike stops like the plug has fouled but as soon as i get a screwdriver in there and bend the electrode back out she is sweet and off i go again. takes about an hour of riding for it to close. it isn't running too rich to be a problem as the plug is often a little wet but is still a nice brown colour. Ive examined the head and piston and cant see any signs of wear. i installed a new piston and rings about 6 months ago and have ridden about 30 hours on it. this problem has occured in the last 3 rides. any ideas??? please?
the only way that the pug gap is closing on you if you are hitting it check to see if it the right plug not to long dont over tighten it and make sure you are using the crush washer on the plug
we raced ktm for years and the past couple of years we have factory support rides, the plug should be a br8ecm at 18-24 on the gap. if gap is closing like the other person said something is hitting, either crank or extreme carbon buildup.they come rich usally go one leaner on the pilot and 2 on the main jets.