Hello JUAN !! i guess i was wrong! it was my understanding that a 1 dot engine was a sport engine. and the the 2 dot engine was the r or race version. what does it say in the manual that indicates that your engine with 1 dot is a R engine?? does the sport engine have no dots. and the r has 1 dot. just would like to KNOW !! THANKS TOM. could you forward the manual to me . as a friend of mine has just bought 3 BVM 91s and a BVM 96. THANKS AGAIN TOM at [email protected]