Rotax Sparkplugs

I have heard of this from a couple of owners, but I have never personally seen one unless it was dropped or someone tweaked it when torquing it in or removing it.

Torleif,

Were there any spark plugs where a chunk of the porcelain was missing?  If so, it might be worth looking in those cylinders with a bore scope to make sure there is no damage.  I’ve not seen it, but it would seem that porcelain is hard enough to scratch the cylinder wall.  

Installed 2 new 912s engines on my Aircam. For 2 months I struggled to make them run properly (thought it was fuel delivery). Turns out the Rotax plugs were defective. Started okay but when rpm was run up to 3,500 they started missing . When I replaced the plugs with my old NGK's they ran fine. Having great difficulty getting dealer or Rotax to respond. 

Ron Lowery

There are counterfeit NGK spark plugs out there being sold as "genuine" -- beware.  NGK recommends only buying their plugs through known legitimate factory-authorized NGK dealers.  I have had good luck purchasing through our local auto parts dealer (O'Reilly's) and AMAZON. 

Dear Torleif,

see the Discussion "Experiences - Comparison "new" Rotax spark plugs vs NGK" in the archive. Broken porcelaine i never see it but i heard about this from my certified service shop - with serios consequences - no responibility from ROTAX - maybe any yeas ago. My personally problem was rough running cased by sooty spark plugs. Maybe there are some spark plugs in your dealers stock from the first series of ROTAX spark plugs. Hope the next generations will be free of this faults (production faults). Nevertheless, there are no "miracles" spark plugs on the market, that means spark plugs who are suitable for any kind of engines, including the entire ROTAX family, unless ROTAX want this, this is unrealistic. Also you can forget the fairytale of detonations which destroy the porcelain. Have any body heard about counterfeit cheap NGK plugs for 3 to 4 dollars (cheap and good), is it not more realistic to counterfeit the 25 Dollar ROTAX spark plugs?

See my comparsion about different kind of spark plugs at https://www.hkk-edv.de - change language and go to Microlight - ignition or downlod this article direct at https://www.hkk-edv.de/content/Comparsion-Spark-Plug.pdf

Greetings