[RACNRAY]

I now have close to 6000 more miles since the intake fix and the skoot is runnin flawlessly.
Since the map that was in the PCV was the map that was made during the last dyno session and there had to have been some small percentage of vacuum leaks at that time, i ended up having to lean out my idle and the lower throttle percentage/rpm rows as those are areas that were most affected by the vacuum leaks, the skoot was even happier after that.

There have been concerns about why the posts on the t/b's are there. Sticking with the "heat transfer" theory, reducing heat in the t/b assembly may have to do with lowering the operating temp of the servo motor which controls the butterflies. This is an electric motor device so it makes sense that we would want it to have the lowest temp for longevity. Besides the airbox the t/b is the part of the intake system that sits the furthest away from the heat of the engine. If the reduction of heat transfer is why the posts are there, then that consideration in design and manufacure has also compromised a good seal between the t/b and intake manifold. The amount of 0-ring compression on my skoot was nowhere as much as i see on other skoots that utilize an o-ring for sealing. When Mark bolted down my t/b he could, by "feel", sense the amount of o-ring compression was similar to what we feel is the norm. We find vacuum leaks are a problem, specially on bikes older than 5 years, as the o-rings (or the rubber lip molded onto the manifold) flatten out over time, allowing leaks. Most manifolds develop a "warp' in them and are no longer flat, needing surface correction.

I try not to overthink things, my experience in working on Jap skoots for over 35 years has allowed me to kinda "learn" their way of thinking.

Back in 1976 Kawi issued a "factory directed modification" on the KZ400's. They had a defective design in top end gaskets and o-rings that had some of those skoots leaking oil real bad. The replacement gasket kit was real neat in that it had new style gaskets and o-rings that replaced the original stuff. I did many of these kits and never had an oil leak after that. It did take Kawi about a year to come out with this FDM.

The HUGE tolearnces allowed in mass production has many affects on many aspects of our skoots. My dyno has proven that time and again. Being able to dyno stock bikes of the same model i have seen HUGE differences in power. Example: the 1999-2007 Hayabusa's average around 150-152 H.P., with 2 or 3 up around 157-158, and a couple down at 146-147! A 12 H.P. spread! Think of the THOUSANDS of machining operations it takes to make an engine! We do alot of cylinder head porting/polishing and i have seen, just in heads i have had apart, noticeable variations from head to head. I am currently doing a 2009 R1 head, and it's interesting to see how the ports match the valve seats on the #1 cylinder pretty good, but the match of port to seat gets worse on cyl's 2,3&4 being the worse!

I am waiting on Chris to finish the break-in on his Vaquero so we can document his power (and compare it to mine) and since he is having some funky running characteristics i wonder about vacuum leaks on his skoot. We shall see.

RACNRAY