GreginDenver

Yeah, revealing any sort of qualification or expertise in today's online environment is to invite ridicule. But I do it anyway (occasionally). And no, I don't exactly know the particular joke you're referring to. Maybe it's more of my "expertise" getting in the way of what I'm sure is both a very pithy and absolutely hilarious joke (In my Air Force time I was a safety officer and crash investigator so I actually do know what's dangerous).

I'm an Airline Transport Pilot, the highest level of certificate. For 20 years now I've made my living flying your family around. Plus 20 years as a military pilot. I take maintenance seriously. When I discovered that the 42mm gaskets were slightly oversized for the cylinder head exhaust port seats and and saw that under the stress of the install-crush they were undergoing serious deformation: doing things like bulging into "out-of-round" shape at the sections of the front cylinder head exhaust ports where there's no retaining sidewall, and actually being "unrolled" against the retaining sidewall by the force of installation in the rear cylinder head ports, I pulled the plug on using them. I didn't say anything about whether or not you might be able to get lucky with these gaskets and achieve a good seal at all four cylinders. But using a part that doesn't quite fit and depending on some luck to bring it all together isn't my style. So far I've only seen how the 42mm gaskets behaved during my test installation on my '99 5th Gen. Show me some "after" condition pictures of the 42mm gaskets performing flawlessly on other bikes and I'll STFU.

At this point I'm wondering about which type of gaskets you used when you installed the New Header. If you used the 42mm copper gaskets from Delkevic they might be part (or all) of the problem. Did you see the thread (with pictures) that I posted when I was trying them?

Yes, you've made a connection most people just don't get: That for a given fuel injector "pulse width" (commanded by the ECU) any increase in fuel pressure (even just a slight increase, delivered by a slowly mechanically failing FPR or an FPR operating in a vacuum-starved condition) will deliver a richer mixture to the cylinders. My '99 5th Gen has a late-1998 production date on the VIN sticker, which means the bike is now 21 years old. Who knows how long the diaphragm inside the FPR was designed to last? I don't know. Does the spring inside the FPR stay in perfect factory calibration forever, or does it slowly lose that original calibration? I don't know the answer to that either. What I do know is that my '99 5th Gen often gives off a stinky-rich smell when I'm sitting at stoplights and stop signs. Some of the bike's components are considered "consumable items" and are meant to be treated as such. Things like fluids (hydraulic and coolant and engine oil) are the most obvious and often replaced, but other things are consumable on a much longer timeline. The FPR is one of those. As mentioned, I really don't know how many years the VFR800 FPR is intended to last, but I've decided that now, at 21 years, is where I'm making the call. I'm combining this FPR replacement decision with: 1. cleaning the carbon off of the backsides of the intake valves, 2. having the fuel injectors professionally cleaned and evaluated. While at the same time installing the New Header system and replacing the water pump due to a failing/slow-leaking shaft seal.

Well, if the bike has gone all stinky-rich at idle (which you didn't mention in your original post) then you should ignore what I said and instead suspect that perhaps the RB module (or the Honda PGM-FI ECU) is confused by the mixture-ratio that's being induced by the New Header and is overcompensating. Sometimes an O2 sensor that's experiencing an "off-scale" air/fuel ratio will default to a really rich or really lean output reading.

Better exhaust system means more flow, which means (maybe) that installation of the New Header has given you a lean-idle condition. Does your RB module allow you to rich-up the idle fuel supply?

Formula 1 racing is using a 1.6 liter V6 engine in the current formula configuration, but before it was finalized they were also discussing going with a 1.6 liter V4. I wish they had chosen the V4. The rumor was that all of the manufacturers except Ferrari were willing to go with the V4, but what Ferrari says is what goes

You're saying that carbon buildup belongs in the same category as Flat Earth and Sasquatch?

I think the wad of spiral metal is only there the help out when the fuel quantity gets low.

Now that I've posted up the condition pictures of all 8 intake valves here are some evaluation/thoughts… (I think that people who have a lot of experience wrenching on engines might find this interesting so hang in there, I'm going somewhere with this...) First, my main reason for tearing into what I think of as "The Stack" (fuel tank/airbox/throttle body) again was to gain access to the fuel injectors (just saying that cleaning the intake valves wasn't my primary purpose in the tear-down). Backstory: I've owned this bike (a '99 5th Gen) for 2 and 1/2 years now. When I purchased the bike I treated it to a pretty thorough refurbishment because I was really excited about finally owning a 5th Gen VFR and wanted my experience of the bike as be as close to "like-new condition" as I could get. But for some reason (and I can't remember why) I didn't send the injectors out to be professionally cleaned and evaluated. I've been kicking myself about this for a while now. Not long after I posted up this forum thread Grum brought up the intake valve "fuel-washing" effect of the VFR's port injection which should help to keep some of the carbon buildup off of the backside of the intake valves. When Grum reminded me about this effect I realized that the amount of carbon buildup I was observing on the backside of my intake valves was actually telling me good bit of information about the performance of each cylinder's fuel injector. Here are my findings: if you look back up in this thread at the individual intake valve pictures I posted of Cylinder #3 and Cylinder #2 you'll notice these intake valves are very dirty. Then when you look at the pictures of Cylinder #1 and Cylinder #4 you'll notice that these intake valves are pretty clean. Having seen this I'm predicting that when the injector cleaning report comes back to me from the injector specialist later this week it will say that the fuel injectors for #3 and #4 were not spraying very well, and the fuel injectors for #1 and #4 were spraying normally. We'll see how that prediction turns out, but I'm reasoning that the intake valve fuel-washing effect will only protect your VFR's intake valves from carbon buildup if the fuel injectors are spraying the correct amount of fuel with the correct/proper spray pattern. Poor output or a messed up spray pattern will probably result in more carbon buildup.

Here's a "before" pic of the Right Intake Valve of Cylinder #1 Here's an "after" pic of the Right Intake Valve of Cylinder #1 Here's a "before" pic of the Left Intake Valve of Cylinder #1 Here's an "after" pic of the Left Intake Valve of Cylinder #1 Here's a "before" pic of the Right Intake Valve of Cylinder #4 Here's an "after" pic of the Right Intake Valve of Cylinder #4 Here's a "before" pic of the Left Intake Valve of Cylinder #4 Here's an "after" pic of the Left Intake Valve of Cylinder #4

And never, ever drive a car or motorcycle on public roads... average 35,000 deaths per year out there (U.S.).

Yes, agree completely, PEA is great stuff. I'm using it to do the cleaning pictured above in this forum thread. When you're applying it (PEA) directly, as I am in this case, you can see it reacting with the carbon buildup, it instantly foams and bubbles when it contacts the carbon.

My guess is that over the lifetime of a (port injected) vehicle (like the VFR) the intake valves probably build up a certain amount of carbon and once it reaches a certain level of fouling the accumulation stops (or at least slows to almost nothing). There's probably a balance of opposing forces that asserts itself at some point (injector wash vs. oily crankcase gases) and the amount of carbon on the backside of the valves stabilizes (or perhaps it's a better description to say that after the accumulation reaches a certain level the accumulation will then yo-yo back and forth over time between a minimum and maximum). So, yes, I completely agree with you that the 80,000 or 100,000 mile VFR engines are very healthy. I just wanted to experiment with bringing my intake valves back to "as new" clean to feel what that's like (I've also sent the injectors out to be professionally cleaned and evaluated). But as I was discussing with Grum, this "balance of opposing forces" does not occur on Direct Injected engines. It appears that these engines just continue to get worse and worse until their performance drops to a point where the owner can't stand it.

Yeah, sorry, you know how it goes, when you've decided on the solution you're going to use it puts the finish line in sight and you start looking forward to test-riding the bike. I definitely preferred the results I got with the 41mm copper gaskets over what happened when I tested the 42mm copper gaskets. This is still very much a situation that's "in play", it may turn out that another New Header purchase forum member will come up with the discovery of a completely different gasket solution that would be better than the 41mm copper gaskets from Delkevic. But at this point I firmly believe in the 41mm as the best solution I had available. I was very impressed by how neat and easy it was to install my New Header. I used a "spreader" type clamp to ease the header around the center stand crossbar (which is slightly smaller than the center stand leg), this worked great. My New Header matched up to the exhaust ports just as others have described, so I used a couple of Thule Rack cargo straps to put some pull force on where I needed it, like having an extra pair of hands.