That is good info for me regarding the rs125's, Interesting thing about the carbs, do the rs125 riders have good results with the use off a 34mm carb or do they all use the 28 or 30mm?
35Hp seems far away for the tzr125 at the moment.
Once, I've read on a technical magazine that a tuning specialist obtained 37,5 hp out of a RS 125 using a 37mm carburetor with handmade reed valve!
The Sport Production Championship in Italy during the 90's obliged all the bikes to have a 28mm carburetor. So the factories developed this solution with excellent results, expecially because on the tracks they are looking for maximum power at the highest RPM. So the 28mm with a perfect carburetion plus a racing exhaust did amazingly the job.
Since there was this limitation, almost nobody brought the 34mm carburetor solution to its limits : so who can tell if a 28mm works better of a 34mm?
The only one remark we can do regarding the Yamaha 3MB/4DL bikes is that the 32mm VHSA is more a "racing" solution than the 34mm VHSB. Another remark is that the TDR 125 R with the same (stock) engine and 28mm carburetor instead of 32mm, has 4hp less than the TZR 125 R. These four hps come straight from the carburetor and the exhaust.
About the V-FORCE 4, this reed valve has twice the useful area for the flux of the air-fuel mixture: reed's stiffness and thickness are calibrated in relation to this peculiarity. The differences using a 34mm versus a 32mm carburetor could be minimal. This is a great upgrade.
By the way, I am preparing my new intake manifold with optimized and revised flows to make the most of the pressure waves and the original reed valve. We'll see how it will go in the first tests, I'm really curious!
As soon as I'm ready, I'll post something more on the forum to get you all involved.