The Honda PCX / Forza / ADV150 / SH Forums

I noticed my fuel millage was tracking down after about 7000 miles of ownership. I thought it was the belt wearing away and I'd have to suffer with low mpg numbers until replacement. I made sure everything on the PCX was correct, in spec, and functioning properly.

Then, on a whim, I decided to pull the spark plug. Sure enough, the gap had expanded to over .054 inches (1.37 mm). Which is much too big, and out of spec per the manual. I replaced the plug a 600 miles to an NGK iridium. After 8500 miles on the plug, it looked great! Just the gap widened.

Reset to middle of spec .033 inches, and then tracked fuelly fuel milage. I'm happy to report I've increased MPG on the last 3 tanks by over 6mpg! I'm back to where my scooter averages out.

And before you ask, yes I set the gap correctly before I originally put in the new plug at the 600 mile mark.

I'm going to pull the plug every other oil change now and check the gap.

Strange that your plug is wearing so quickly. I see Bosch platinum plugs that are still running fine and are just replaced on principle at 100,000 miles in the Mercedes I work on.

I have another plug identical to the current one in use. I did t see any wear. Compared to the new plug Just the gap had widened. That is the strange part.

sendler2112 wrote:Strange that your plug is wearing so quickly. I see Bosch platinum plugs that are still running fine and are just replaced on principle at 100,000 miles in the Mercedes I work on.

Are you a tech? I'm in the main dealer in Edinburgh (Scotland).

32 years MB tech.

You beat me slightly. 29 years for me.