Cutting the CDI will alow you to get higher rpm. Up to 9000. This should only be done after you've removed your restriction in the CVT, or if youre very careful not to let the rpm get too high. Double the rpm and you've quadrupled the wear om the engine, give or take, so no reason to drive high rpm, if you can get higher speed simply by making the CVT better.
When you've removed the restrictions, you will go further per revolution of the engine and therefore you can increase rpm without significantly lowering the life of your engine, measured in distance driven.
9000 rpm won't give you imidiate engine failure. I've had the 1 spring per valve version up to 9000 rpm a lot of times without failure and with the 2 springs per valve version i have had the original engine at 12.500 rpm.
When this is said, the force acting on the connecting rod is a function of the mass of the piston times the speed it moves at squared. Double the speed (the rpm) and you'll quadruple the force on the engine parts, so a minor flaw in the metal will become critical. I know a guy whose connecting rod broke after he derestricted it and Kymco wouldn't give him a new engine because he derestricted it which put more stress on the engine parts.
But that's the only guy i've heard of.
I have not done the calculations, so i do not know how much stress the connecting rod are exposed to. I will need the weight of the pushrod and some measurements of the diamentions. I already have measurements of the weight of the piston. If someone can supply me with this, i will be able to tell you the stress of the rod. To precisely tell you what the rod sould be able to cope with and what is material flaws in the production, i will need to know the material, which i will possibly roughly be able to estimate if someone can supply me with a sample. Broken or not, as long as there are more than 4 square mm free plane surface, so i can check the hardness and crosscheck it with CES Edupack material library.