Hello Everyone.

Could you please tell me which spark plug is supposed to be used for converting a 120 size Webra Engine to Gas.

- CM6 Plug (10mm x 1 thread)
- Regular Champion Weedwacker spark plug (Anyone nows which thread they are?
- The new 1/4 x 32 spark plugs (such as the one used by NGH GT 9cc)

For me living in MĂ©xico city it would be much easier to have acces to Regular champion ones, but need to know which ones fits correctly for doing this conversions.

If anyone could tell me how to measure or adjust how deep the spark plug needs to be in the engine as some of this spark plugs are longer than regular glow plugs ....that would be really helpfull.

By the way Im going to be testing this weekend and OS MAX 61 SF with constant heat to the glow plug and regular premium gasoline with 5:1 oil (20% synthetic MOTUL oil) ...

In advance thanks everyone.

VĂ*ctor Arreola.

The little 1/4x32 spark plugs screw right in and replace a glow plug, no problem. You would have to get someone to redrill and tap the engine head for a CM6 spark plug.  But the CM6 may be too big for some engine heads, as you have to machine the fins a little to clear the plug and spark plug cap. You need to determine if you have room for it in the head.  There are several brands of Chinese made 1/4x32 plugs that work OK, RimFire makes  a 1/4x32 plug too, NGK also has a 1/4x32 plug.