im not sure about the a3 bbut ive had many engine problems after new front engine crank bearing os #8 ive got rid of all my problems and i only got it up to 300 degrees with alot of hig hpeed runs and before the top speed advertised was not able to be reached but today it sure looked like 50 so my adcice seal the back plate with rtv sealent loosen the carb push it down tightly with your thumb and re tightem if that dosent work replace the front bearing and expirement with diff glow plugs it says in big bold letters in my manual do not run the #8 but icant get over the preformance


the stock plug med long #50017 not sure about that number but the package saya for .12 engines