spark plugs uneven burn

[timberlite]

Originally posted by Ungas
It could be possible that the valves don't fully close with respect to its clearances. Or valves in 1 & 3 chambers don't fully open to let the air or fuel in.

Have you checked on air and fuel delivery?

thanks Ungas,
so i'll have the valve tappets corrected? could this be related: sometimes when i pop the hood, i hear a slight "tst-tsk-tsk" sound under the engine cover.

did a check on the air & fuel delivery. saw the stock paper filter looks clean enough; used carb cleaner spray on the carburetor's mouth (some sludge/dust removed from the choke)

Originally posted by Jackaroo

Also check hi tension cable resistance, your spark may be weak on 1&3.

thanks Jackaroo,
i'll also look into this. high resistance, weak spark? anyway, i'll compare the wires 1&3 to 2&4, they should be equal right?

i'll get back to this thread once check-ups are made over the weekend. thanks again!