cuoccimix

Thank you to all for the punctual replies and analysis. I have a (partial) update. I have tested the bike on a short distance. That did not allow me to fully accelerate in 6th gear, but i have noted that the clutch DOES NOT SLIP anymore in 6th. That must be confirmed with a faster (and longer) trip, but apparently the slipping has disappeared. Not sure, but the clutch works way better, This leads to what i was thinking long before purchasing the Oberon slave (and to what Sebspeed said). I live in a very warm area (South Italy) and during summer it happens often to ride in a quite chaotic traffic. Once the coolant reached a temperature of 100 C, the clutch was struggling - not a lot, but in quite noticeable way. That was a red flag. Blame to me for not spotting the problem, but i'm not a mechanic. Probably the original slave was already half-cooked. Less than two years ago, the original clutch began slipping in 6th gear at 7000 rpm (just at first, then it stopped after some other accelerations). Diagnosis by the workshop, "replace clutch plates". I bought a complete set by Newfren, a good quality brand in Italy. They did not say anything about the slave. Clutch replaced, master cylinder serviced, springs preloaded with spacers. Worked fine for some time, then my hand began to hurt, and after some time the clutch began to slip again, The response - "you're driving too hard". I drive fast, but i don't use my VFR for drag races... The Oberon cylinder did not fix my hand problem -on the contrary, it fixed the slipping problem. And the gearshift works MUCH better now - it was working like sh*te lately. So, as alternative spare part, the Oberon slave makes much more sense. Conclusion: probably i have burnt 2 clutches because the original slave did not work well, and the workshop did not said to replace it. Not bad, uhuh? First of all, i will change workshop. It's an Harley workshop and probably they have no time and will to fix an old viffer - big HD bikes make big HD money. Would be the same with a BMW or Ducati workshop of course. Second, i will make remove the preloading spacers from the clutch springs (if the springs are still good). That should improve the effort on the lever. About the riding position, levers and switches are already aligned in the best possible way for the current stock setup. I would like to move the clutch lever/pump 1 cm to obtain a better leverage, but the bar does not allow that, being thicker near the fork stanchion. Step by step i will fix the situation.

Thank you for the wise and balanced suggestions. Yeah, i have thought to various solutions for driving position. But i discarded them all for various reasons. Variobars are damn expensive. ABM kits are practical but aesthetically horrible from my point of view (i hate tubular handlebars on VFR). Spacers/risers under the original clipons are almost useless. I did not trim the locator tabs because more "open" clipons would paradoxically make the position heavier on the front. As only viable option, i was thinking to get clipons with different shape from another bike, i.e. VF 1000 F or something other to allow a further back position. Currently i'm using an heavily padded left glove. No problem (almost) on the right hand, no problem in braking. About the clutch, master cylinder was serviced one year ago with new gaskets and everything. Still has some squeaking noise though - not very sure if the workshop did a good job, also because i replaced clutch plates 2 years ago (with spring spacers that i will remove) and now they slip again in 6th gear. So there is still some work to do. Braided line is also a good advice. Sure there are still lot of things to do, but the basic fact is that the Oberon slave alone is not resolutive, and with a negligible difference other things being equal. Mine is CLU-3038 specific for my bike. Radial master would be nice, but it would alter the originality of the bike (yes , i'm a bit conservative about that...supercharger is cool though 😉 ). And more €€€ on the way. First thing to do will be to fix the slipping problem, so i will remove the useless preloader spacers installed on the original clutch springs. And then....well, i will try with more cortisone and more hyaluronic acid!

Travel is not important. I just need a lighter action on the lever. A lighter clutch needs a wider range of leverage though. So i need something with a long travel (more leverage) but still able to disengage the clutch safely. I have read that 14 mm (the size of the 5th gen master cylinder) is already the smaller one among Honda master cylinders...

What could be an adaptable master cylinder? I would prefer something that doesn't alter the look of the bike, possibly from other old Hondas. Something that allows me to take advantage of almost all the travel of the lever, without compromising its functioning.

As said, i have a problem on my left hand. So i needed something to ease the effort a bit. Also i have noted that 00-01 5th gens have a slightly lighter clutch. I'm even thinking to replace the whole clutch basket and plates with a 00-01 one, if possible. It seems they are smoother and also more resistant (i have slipping problems in 6th gear).

After much hesitation, I purchased and installed an Oberon slave cylinder for my '98 5th gen. It costed over 200 euros including purchase, shipping, customs fees and installation. I was expecting a decent improvement, but as soon as i picked up the bike from the workshop, the disappointment was almost total. The load required to operate the clutch has decreased by 10% - 15% in my opinion. Not more. Pretty much a negligible gain. The only advantage is that the lever is smoother, but that probably comes from the fact that the old slave was 25 years and 75,000 km old. The effort to pull the clutch is almost the same. I am so disappointed that I would be tempted to take it apart and resell it, but it would not be worth it. The most irritating thing is that the point of engagement has remained almost the same, a sign that the leverage ratio has not changed much. In my opinion it could have been increased slightly (there is still a lot of travel) but evidently in the design phase the leverage ratio was not increased further to avoid problems. Surely my rhizarthrosis is quite demanding, but ultimately a bigger slave is useful only in combination with other interventions (clutch springs, clutch lever, master cylinder, physiotherapy, etc.). Not that it's useless, but I don't agree with the people that review it as a definitive solution. Probably it's a decent gain for their needs, but not for me. Just my 2 cents. Question: Is it possible to install another master cylinder or another lever to increase the leverage? Assuming of course that disengagement is not made impossible at that point.

Hi everyone, I have a 5gen ('98) and I love it madly. I wouldn't trade my VFR for anything in the world! Unfortunately I have some problems, driving position and clutch are making it more and more difficult for me to use it for long journeys. I would like to know if the Oberon slave cylinder can make the clutch of my '98 really lighter, or if the gain is negligible. Thank you!

I have installed a Power Commander unit on my bike....but it's not a modern one. It's quite a old piece of vintage electronic, being a PC II, made in 1999-2000 (found a new old stock one, still with sealed box, for one hundreds euros). The box itself is quite self-explaining about the age of the item: The installation is very easy - just unplug the original harness, and plug the PC II betweem ECU and original connector (no additional plugs are present on this old device). It sits quite well under the seat, but it was not possible to hide the connectors in a less invasive position. The plastic hooks under the seat are perfect to fit the wire properly. After a bit of struggling with adapters (the thing has a serial port!) and with unusable software, i finally managed to install the proper files and to connect the PC II to my notebook. I have installed a map previously tested by a member of the Italian VFR club, and now the bike can run for almost 280 km until the res light - that's a gain of 40 km. Performances are almost unchanged, just a slight loss of stamina and smoothness at low rpm. Now the bike stays in the range of 16 km/l (almost 38 mpg), and that's an acceptable mileage, albeit not impressive for sure. Now it's a VFR-BNSO (Very Frequent refuelling, But Not So Often).

As said, it seems that every '98 owner in Italy gets bad mileage, regardless of the injectors conditions or the speed. Y2K catalyzed models are known for having a MUCH lower fuel consumption. The bike runs great anyway.

I'm going to replace my original headlight bulbs with whiter Osram Night Breaker bulbs, and i have seen this beautiful mod: The mod is visible in this video Now i just want to know if those LED bulbs may cause problem in the long term. I want to stick to halogen in the headlight, exactly for this reason. I would like to use LED just for the turn indicators and for the parking light. Am i doing right?

Hi, sorry for not replying immediately to this interesting debate. Well, what can i say...When i did the flapper mod, i got an immediate advantage at very low rpms (under 3500 rpm, so to say). The V4 is not the smoothest engine at those rpms anyway, but now it's much better. Don't know why it behaves in this way, it should be the opposite (open flapper valve = roughest behavior at low rpm), but currently i will keep the flapper mod. Snorkel mod - just a matter of better noise 😉 Gas mileage? It's always the same - bad. You go slow, you go fast, it seems that the injection system was originally set to always squirt as much gas as possible in the cylinders, regardless of the conditions. I drove my bike for half tank at hilarious city speed (3000-4000 rpm) and the result was always the same , a miserable 235 km (146 miles) from a full tank, excluding reserve. Just yesterday i heard another 800 Fi owner - he had one non-catalyzed (1998) and one with catalyzer (2001). Well , he said exactly the same things - the '98 has a better punch at midrange but has crap mileage and runs always quite rich (the exhaust is always a bit blackened after some hundreds of km). Fuelly mainly shows results from US bikes, the few non-US bikes have worse result about gas mileage. Exactly for this reason, i would like to know if there is some differences between the 1998-1999 Italian-European ECU and the USA one.

eheh, that's a good question....I'm a big guy, but my weight was the same on my previous ZZR 600. As Thtanner said, i'm chasing ghosts...i can't really cope with the fact that there are other bikes from the same years that have an higher mileage. I bought the viffer also for long travels and that fuel hunger really pisses me off, actually it prevents me from embarking more often in long journeys. You know, average price in Italy is 1.60 Euro per liter. Yesterday i checked out the average 5th gen mileage on Fuelly, and apparently US bikes have a lower consumption than EU bikes. I even thought to install a US/California ECU. Apparently i got 10 km more after pouring a can of injector cleaner in the tank. Will try to buy another can and/or to manually clean the injector. Wow, if only we had lower gas prices, i could live with that.

Thank you. I had also another '98 under my eye, in total black, but it was impossible to resist to this red beauty 🙂

Hi, air filter has been replaced, no dragging brakes, the bike works well but i never checked the fuel pressure regulator. I had some FI issues caused by bad connectors and/or ground connector. Now it' OK and i have also poured a whole can of injector cleaner in the tank. The gas mileage was always the same - never seen a real improvement. JZH, i live in Bari, South Italy. Quite far from the classic "motor valleys" in the North, but we have nice roads here too 🙂

Hi, this is my '98 5th gen VFR 800 FI. I bought this bike one year ago with 27500 km on the clock. The bike was like new - not a single scratch or rust spot. Went through a very long series of small issues (R/R, connectors, etc) caused by the long inactivity of the bike. Now they are all solved, except one - the gas mileage! It is pretty bad, around 14 km/l (33 mpg) riding in "mixed" mode (around 5000 rpm with some high speed launch). The exhaust always smell a bit rich, the bike runs well though. I did the usual snorkel / flapper mods, went through a lot of discussions, somebody says it's a normal mileage for a pre-cat bike, somebody other says i should clean / synchronize the injectors, but my mechanic says that everything is OK on my bike. I would like to know if the bike mileage is normal and if it can be improved without buying a Power Commander. BTW, it is true that US bikes from the same year have a different ECU? Maybe they have a better gas mileage? Thanks!