Originally Posted by Sideshow Bob

i broke in two B5 pros this week for our upcoming nationals..the one with a 2057 and the other with a 2058 and i have to admit the smooth power delivery of the 2057 was VERY impressive. Both were in mugen mbx6R buggies,25% nitro with p3 plugs. The one with the 2058 felt very aggresive. like stated above the runtime in effect was the same. on a side note though...I always silcon seal my engines. the b5 pro on the 2057 was sealed by the owner and the one of the 2058 not. breaking in was easy on the sealed one, like clockwork...the other one, well lets just say i was ready to throw it in the bin..but coulnt...because it wasnt mine after chasing a stable idle and whatever was causing this tuning issue, I decided to suck it up and seal his motor for him. Problem solved, so it had to be an air leak. if i ever needed proof that it is an absolutely necessary preparation then this was it. Two identical motors. Both of them are now running and tuning the same and could probably idle for days lol. Good engine.

PS, i use the break in/tuning method on the first page of this thread on all my motors, even my O.S's and it really made the wholebusiness make sense to me for the first time ever..foolproof, thanks again Ron