HI AS A BEGINNER OS EASE OF OPERATION IS A MUST UNTIL YOU GET TO KNOW THE VERY UNIQUE QUALITIES OF GLO ENGINE OPERATION OS KEEPS IT SIMPLE AS IS POSSIBLE AS THE BREAK IN PROCEEDURE WITH MOST OTHER ENGINES IS A BIG LEARING CURVETAKES A GOOD DEAL OF TIME TO MASTERAND CAN PUT YOU INVESTMENT IN YOUR AIRPLANE AT RISK IF NOT TOTALLY UNDERSTOOD-OS'S BASICLY RUN OUT OF THE BOX AND KEEP YOU RUNNING IN THE AIR-DEAD STICKS TO A BEGINNER CAN COST AN AIRPLANE-THAT GETS EXPENSIVE-DO WORK WITH A GOOD INSTRUCTOREVEN AFTER YOU SOLOA LITTLE MORE POWER THAN YOU NEED IS ALWAYS BEST AS IT HELPS STABILISE THE PLANES FLIGHT-MARGINAL POWER WILL ALWAYS MAKE AN AIRPLANE HARDER TO FLY-NOT GOOD-FOR A 40 SIZE AIRFRAME GO WITH A 46AX OR A 55AX YOU CAN ALWAYS THROTTLE BACK GOOD LUCK IN THIS VERY GREAT HOBBY ENJOY REGARDS TONY-RC- 20 YEARS

Ihave found the Thunder Tiger GP42 to be as easy to tune and break in as any other engine. Mine will turn a Master Airscrew 10X6 to 13,500 out of the box on 10% . That should be plenty of power for the average trainer unless you are learning 3D.

Kudos for JPMacG on his very clear advise!
Regards

bigedmustafa. Do you have any more information from that post from Dr Nitro? Im' curious when were those tests done? Where is the original posting?

There should be a member list here somewhere. I suggest using it and PMing Dr. Nitro.

http://www.rcuniverse.com/forum/m_48...tm.htm#4892802
Interesting peeling issues article that might shed light on "reliability" carried over from earlier OS model engines.

He's got 50 posts listed right here.

http://www.rcuniverse.com/forum/sear...20Nitro&top=50

I'll put my 2 cents in for the TT Pro .46. I still have my first one that I got around 13 years ago (give or take) and it still runs great! Now to be fair it doesen't have the legs it used to but it will still pull my Tower Trainer around no problem. It has about 25 gallons of fuel through at this point with the original bearings. I am also a fan of OS engines and have had great luck with them over the years, both 4 stroke and 2. But to be honest my absolute favorite 40 size mototr is the Thunder Tiger. It is so easy to tune and doesen't really care what you put it in. Another great thing about using it in a trainer is the fuel economy. I had my throttle linkage come off in flight one day (stupid easy conectors) at half throttle and the dang thing ran for almost 30 minutes before it died! I was worried about my receiver battery dying and was about to plant it into the dirt to prevent a runaway. There has been alot of good suggestions here and do what works for you. The TT Pro 46 is a great engine and you will get years of service from it without a doubt. Good luck!!!

Sooooo, have you made a decision yet?  Looks like a coin toss to me.

He has not logged in since 2007. I wonder if he is still on this earth?

He probably went electric and posts for advice to stop burning up those speed controllers. Just kidding.

Hey just came across this post about the tt pro39 engine, i have just posted a similair problem with the conrods breaking with these engines.

Avoid tt pro 39 engines i reckon.

Have had the exact same problem with my tt pro39 engine, two conrods broke on me too.

Been modeling now for about 6 years and never had this happen to me before so what does that tell you.

I think their crap, will get OS.