As mentioned in other threads last day or so a recording of my "stage 4" on the dyno in march last year.
When he was taking about it dyno man said that early on the raw fuel was spitting out the exhaust at times.
I had been riding it for quite a while like this and riders told me it was very fumey to ride behind.
The head job that Patrick racing do is pretty good. Make sure you dissemble it to clean though when you get it.
2mm bigger valves, high lift and porting that enlarges the inlet port a lot.
So the 43mm inlet manifold and throttle bodies used on Stratoliners and others do the job. They are identical to standard, just scaled up. Its easy to grind a bit of material away to fit them up.
The head job is what doesnt get touched in the ordinary stage 3 system. The difference this work makes is dramatic and finishing it off by improving the inlet (which just couldnt manage first time round) is perfect. I,m sure you could go bigger with lots of new hardware. The cam Patrick use is not much different to the stage 3 yam one but think lift is greater.
So before the extra inlet work was done it had about 115hp at the wheel. After, it has 120. It feels a lot sharper. It also runs approx 75mm velocity stacks which is about what the stage 3 ones are. Mine are silcone hose inside large pods. They dont have flared or even rounded edges but I think still work. I like to think that being inside a large pod gives them a "still air situation" like an airbox does.
The dyno man said the rear wheel was spinning up a little bit.
Link to the sound file i took with the phone in the shed.
https://sndup.net/7h4t
