The SK engines are so good and the design is about everything I was looking for in A two stroke I have given up using anything else. This engine is designed to be A high torque engine with lower RPMs so it is about perfect for that laser you have. DON"T TRY TO FLY THAT PLANE BY YOURSELF!!!!! There was A bit of A miss print in the instructions about props. The 90 requires a 15X6 or larger, A 15X6 is A good one to start out with then you can start that magic search for the perfect prop for YOU. I say you because there is no perfect prop, it's the prop that keeps the engine in it's working RPM range and will fly the plane the way YOU like the plane to fly. I have had the SK .90s in A 60 size Aeromaster bipe, A 60 size Kaos and A rather big for A 60 size Extra 260, sort of like your Laser. A 15X6 or 15X8 is my prop of choice. The 16X6 and 16X4 were also good. I keep the engine around 11,000 rpm or there about. It's A stump puller and at 100 bucks I found it the best engine on the market. That is the best two stroke engine for me, there are A lot of other choices out there that fit other people A lot better. That 13 inch prop will make your engine run lean and you will never get it in tune. I have never run the stock muffler on any of mine but that is just because of the planes I have had them in.
About the plane itself!! No sim is ever going to be anything like the real deal!! Etch that in stone. You can fly the computer tell dooms day and never be up to that Laser. The sims are A big help and put you ahead of the learning curve bvut they are not real!! I use the sim for learning new stunts only. It gets me brain and hands working so I don't have to do A lot of thinking. That works for me pretty well but I have been flying RC for A while.
If you want to know more about your SK then contact RC Report magazine and buy the Janurary 2007 issue. Ed Moorman did A pretty in depth write up on the SK 90. I think highly enough of Ed to have gone ahead and bought one to give it A try. It was everything Ed said. After using them A lot I have never had ond dead stick?? I can't say that about any of my other glow engines. Mater of fact, if you call RC Report just buy that back order and subscribe, you won't be sorry!!!
Gene