G'day I have 11 Saitos ranging in size from the diminutive 30 to a upper mid size 120. They are all great engines but they do need some running in and familiarization to give their best. They almost always come with the LSN set very rich and they do need about an hour of running before you can get them to idle properly. I would suggest that if you are going to invest such a lot of time, cash and effort in building the B25 that you also buy a cheap 60 size trainer to get the engines some air time and to help you to become familiar with them. I use a large 60 size trainer called the Boomerang 60 which is solid and does this well. I have had engines up to 91 size in it and it makes a great platform for getting to know my larger Saitos. I do the same with the smaller ones by putting them in a Sig Kadet Senior. I am currently fitting a Saito 72 to one Kadet for just this purpose. I found with a previous 72 that it took about an hour and a half of flying for the engine to give its best. You can see the improvement in each day's flying. Enjoy your Saitos. I do.