Honestly, there isn't even that much skill involved in tuning a glow engine. Assuming you have a good one with no air leaks, it's very straightforward. Set the high speed needle, then go to idle and set the low speed needle. Get a good idle, then get a good transition, then reset the high speed. Then you are done! A tachometer makes it really easy; I can do one in about 2 minutes. A tach is handy in a lot of other ways too. It can give you an early alert that something is wrong, and it can show you the effect of different props and fuels.