Hello. I have a .48 glow 2 stroke MDS engine. I bought it used but it feels good compression and looks like new. They sold it because it didn't develop in high speed. He's got a very good ralentํ speed. I've tried everything so I can carburete it, but it shuts down high. I've done all the possible combinations with the 2 squeezing, but it's off high. Low works very well. Will he be haunted? For 50 years I use 10% nitro and do not think the solution is to increase it to 15% nitro. What's your suggestion. Thank you in advance.