5 replies to this topic

[wulbo]

I see the cmr7h is the favoured spark plug. Is there diffrent types of cmr7h's for 23, 26 and 29cc engines. I assume the depth's the spark plugs go, should all be the same as it's the width of the piston that changes? Any help appreciated

Who offers decent deals on these types, thanks.

[Spriggan]

Most engines take the same plug. One thing you do have to watch for is the length of the plug outside the engine, some plugs are longer than others, so if you have an upright engine the plug can hit the top of the bodyshell or rollcage and even get broken off easier.

[hebby]

Spriggan, on 02 February 2012 - 10:44 PM, said:

Most engines take the same plug. One thing you do have to watch for is the length of the plug outside the engine, some plugs are longer than others, so if you have an upright engine the plug can hit the top of the bodyshell or rollcage and even get broken off easier.

I have broke loads on my balckout   blackouts roll cage is rather flimsy

[Tamiyacowboy]

spark plugs are numbered. this means that they fit certain depth heads.

they also have different heat range and sizes. both in bottom thread length and the overall size of the plug.

some are compact versions of the same plug. some look the same but have a longer or shorted threaded base, and even then they have different heat/temp ranges.

only one name comes to mind for sparkplugs NGK

[Mike1970]

L&S Engineers in the West mids, a box of 10 CMR7H for £22.50

In the touring cars we use the CMR8HSA, some of the top drivers use the irridium ones.

[wulbo]

thanks guy's. I'v always been a fan of NGK but at £22 for 10 i think i'll give them a bash