mhavlena

This exact issue happened to me on my Nova Flash Special 0.21.

In my case, the car ran flawlessly until I stopped it. At the next attempt to start, the plug was found warped/distorted.

I added a 1mm shim and problem NEVER re-occurred.

Also, it wouldn't hurt to double check the health of your bearings. Debris could be destroying your plugs (this is only valide if you find your plugs distorted and/or with missing coil.

keavze

i assume you meant 0.1mm shim?

by the way, which is a better method/way to retard the timing? adding 0.1mm head shim or using a colder plug? and why?

mhavlena

Yes, I meant 0.1mm shim.

For the issue that I experienced, changing the plug to a colder one (in my case a 7 to 8) didn't help at all, in fact made the situation worse. Increasing the head clearance with the shim did the trick. Now my plugs seem to last forever.

JDOM111

iTrader: (6)

The plug looks fine when it comes out.No peppering on top of piston.