I had a dead stick on my H9 260 with the MVVS45. No damage as I was up high doing a flat spin and we have a long runway here in Kuwait. The problem was the Aluminium plug holder came broke loose, this allowed the HT lead to come loose. The plug itself remained in place. I have attached two pictures of the plug and one of the holder.

Q1) Am I running too lean? >> 8 & a bit LT's through this engine.

Q2) Who has ever had the plug holder break off like this one? Should this be covered by the guarantee?
On the RT is the 45's that came "loose" , on the LT is a replacement.

Mike

You might be a tad richer on both idle a high speed.
How many hours have you been running? I have never seen a plug boot break, but it is a part that sticks out and sits on an engine that vibrates depending on the way an engine is fitted. I would call it plain replacement parts, just like a spark plug.

Pe, my local model shop replaced the plug boot. Take a look at the crack in this picture.
I will richen both of the needles a bit. I'm not sure how many hours, but I just started on the 3rd tank, I mix 4 LT gas at a time, when the engine cut out.
I'm running a Mejzlik 22x10 prop, with the MVVS 45 INT cannister and a 25mm stainless steel custom made header.

It is always good to have a LHS that gives good service. A crack like this after just 3 tanks of fuel indeed is quick. I have yet to break my first one.