Skeeve

Thanks, that's the info I was lacking that's relevant to size/placement of the holes... That's because you don't need any compression damping unless you take a >50% of stroke hit... Compression damping interferes with the suspension's ability to react to small bumps... Yep. The "little or no money" part is the bit I like. As I like to say: "If it's for free then it's for me!" See, that's the real problem: the compression damping coming into play shouldn't be an "all or nothing" scenario, it should gradually have more play, so that it is more seamless in operation. Let's say the fork has 5" [125mm] of stroke: the escape holes [since that's what they are] for oil in the tube outer wall can be divided into zones. Since the 1st 1" [25mm] is lost to sag, there won't be any holes for the 1st 2" [50mm] of stroke length; that's so the 1st inch lost to sag and the 1st inch of actual stroke used have the maximum play without any compression damping f/x [in this range of small bumps, rebound damping is all that's needed, & not very much of that, lest the forks "pack down."] So, at the 2" mark, there would be the max amount of open wall space [how one determines that will come up later.] Once the piston moves past the holes & occludes them at the 2" mark, some compression damping will come into play, but it will still need to be mild, so to appear more seamless in action and not upset the handling mid-stroke. At the 3" mark, as the piston move down, it will occlude the next set of holes, and move into the "deep stroke" range where compression damping is beginning to become a real need. At the 4" [100mm] point, the piston is moving into the last 1" of travel, and covers the last holes in the outer walls, so that any remaining oil is forced thru the piston damper(s), for maximum effect [hydraulic bump stop time.] Now, how to decide about the sizing of the holes? Basically, it's time for phi. Nature loves phi, & therefore, so should you. The holes in the sidewall should progress in a 1.6x ratio. What is the area of the holes in the pistons? Use 1.6x that for the hole(s) at the 4" stroke point. At the 3" stroke point, use 1.6x the area of the holes at the 4" stroke point. For the 2" stroke point, use 1.6x the area of the holes at the 3" stroke point. Chamfer all the holes after drilling them, btw: not only do we not want any burrs left behind to screw up any seals, etc., but we want to minimize any shear f/x and get the damping medium [fork oil] to flow smoothly thru the holes when it needs to. Adjust the viscosity of the fork oil to suit. Ride on! PS: Did some [literally] back of envelope figuring, and an all-drilling, no welding option using the existing holes in the tube and basing the size & placement on an approximation of a phi-progression would be to use a #1 machinist's drill at a point .925" up from the bottom of stroke [adding in the 2.13" ref from bottom of tube, that would be ~3.06" up from the bottom of the tube], and the same drill at another .925" up from there, or at ~3.98" [heck, let's call it 4"] from the bottom. Then, use a letter N drill at ~4.9" up from the bottom. All these holes would only be thru one side of the tube; I'd space them out so none of them are in line w/ other holes, for strength. Remember, you'd be adding some void space, so you'd likely need to increase the fork oil viscosity slightly. Don't forget to de-burr & chamfer all the holes for smoother operation. Sorry for the 90% of the rest of humanity, but I don't have any metric drills & don't feel like looking up what the metric equivalents to my SAE machinist & letter drill sizes would be. ["That will left as an exercise for the reader..."]

The small valve Guzzis have better charge velocity & hence better combustion. Your Breva has Guzzi's dual-plug band-aid and redesigned piston, along w/ slightly smaller intake valve & decidely smaller intake ports to bring the charge velocity & mileage up, but it makes less total power than a V11. Go read the threads on Mike Rich pistons, combustion chamber design & other stuff that's all about 2 site redesigns old now for the real low-down. Don't forget the less than stellar factory fuel mapping [not entirely their fault, smog regs lead to a bunch of nonsense for a/c motors] for V11s as well. But to keep things in perspective, my old '79 Yamaha XS11 never got any better than about 30mpg, and that had a state of the art combustion chamber for back in its day, not the roughly 60 y.o. combustion chamber design on the V11... Carbs work great on kick-start, magneto-ignition dirt bikes where you need stone ax reliability 'cause you don't want it breaking down 100mi out in the bush. On a street bike, the performance potential of EFI and computerized ignition & timing make up significantly for the potential of having to haul the bike to a shop if anything should go wrong.

Nice blueprint, but since I'm not that familiar w/ the insides of forks in general, & USD forks at all, is the piston stroking up from the bottom or down from the top relative to the tubes as displayed in the bp? I'm assuming the holes thru the tube wall function like the holes in the damper rod in conventional forks, and the piston is solid, forcing oil thru the holes? It would seem that rather than bothering with filling the "B" holes, that just adding additional appropriately sized holes in the 2nd wall & maybe going up to 10wt fork oil from 5wt would be easier for most folks [since adding metal is harder than removing it.] Unfortunately, I haven't a clear idea of how the separate leg/circuits [rebound & compression] work at all in the 'zocchi's, but have read several times over the years here on V11LM that supposedly expert sources have said the Marzocchi's chosen by MG for our V11s aren't really very good, & not worth playing with for "serious" [ie, track] use, but what V11 owner fools themself that they're going to go out there & whip up on the J-brand crotch rockets? If there's something the shed tinkerer can do to signficantly improve the stock forks with little cost but the time invested, I'm all for it!

Maybe I missed it, but isn't the 1st thing to do whenever a bike equipped w/ a PCIII starts running funny is remove the PCIII & see if that cures the problem? PCIIIs are nifty solutions to jailbreaking the efi, but they seem to suffer more than their fair share of electrical gremlins...

The devil is in the details: while someone may have thrown $$ at a motor & not really dealt with getting everything to work together well, the guy who "just put on a pipe & dyno-tuned PCIII" may have in fact done a lot of blueprinting, or just gotten lucky and gotten an engine that had everything just right from the factory [it could happen! ] The fact of the matter is, stacking of tolerances & parts mismatches can go a long way toward reducing the efficiency of a motor: this is why Mike Rich can sell his pistons for so much money, because Guzzi redesigned the heads for the V11, but never put in the matching pistons to take advantage of proper squish, etc. Dual-plugging is a band-aid for poor combustion chamber topography; look at what efficiencies Harley-Davidson was able to achieve Shovel->Evo->Twin Cam, all with better combustion chamber design: those motors were all 2v & air-cooled, but the Shovel was lucky to get 25mpg, the Evo would regularly do 40, and the TC is up around 50, despite big increases in displacement w/ each generation. The 2v Guzzi mill is like a slice off the end of a ohv V8, only w/ air-cooling instead of liquid, and will respond to the same sort of attention to detail and performance niggles that have been laboriously worked out in racing those engines over generations: 1) Fill the cylinder efficiently. 2) Burn the mixture as quickly & completely as possible. 3) Get the exhaust out of the cylinder. 4) Eliminate parasitic drag. Intake restrictions are 1 & 4. Exhaust pipes are 3. Porting the intake is 1 & 4; porting the exhaust is 3 & 4. Sloppage sheets are primarily a reliability issue, but also help w/ #4. Keeping your tires properly inflated is 4. Using no more of the correct wt. of oil than necessary is 4. Dialing in the efi is 2. Servicing the water pump is 4 [oh wait, that's already been done for us by Ing. Carcano! ] & so on... Ride on!

Not AFAIK; it was a one-time deal [which is why we needed to preorder, to get an accurate estimate of the # to produce so the lead wouldn't be out of pocket for a ton of shims nobody would buy.] Since the only reason the stock units fail is because they get cranked down hard enough to keep the front x-over from flopping about & crushed to death from the added pressure, it may be the easiest thing to do to take a piece of stainless wire & weld it at each end to one of the headers and the x-over, so that you only have to crank down the connection btw the two enough to get a good seal, & the wire [fairly heavy gauge, obviously] can do the job of stabilizing the x-over's positioning. Someone else suggested just welding the x-over to the header on one side, but that would be pretty tough to undo if you ever needed to, whereas a heavy wire could be cut & redone when needed w/o too much hassle. It might even have sufficient flexibility to prevent cracking of the header(s), & if done on the back side btw the headers & the engine, wouldn't even be very visible should you need to cut the wire & grind off the stubs at some future date. Ride on!

I seem to recall it was one of the FIAT Pandas ['97-2k1?] We know it was a 4cyl [the WM15 can only support four injectors] & a FIAT. What would be really funny is if the FIAT that used the WM15 was the same model Guzzi stole the air filter element from!

The WM15m that was used on the last Nevadas & Cali cruisers had a lambda but that was only for keeping the engine super lean at idle [since vehicles sitting at stop lights produce a lot of exhaust for no fwd motion]; basically, at anything over 2.5k rpm or thereabouts, the ecu goes into normal open-circuit alpha-N mode. So yes, you'd need a much more modern ecu system if you want to operate in closed-loop efi. Full time closed-loop efi isn't really necessary; if you go w/ something like the MY15, you can run it w/ a wide-band sensor & one of his utilities [sorry, I don't have one & can't remember the entire process as described] to get all the fueling points dialed in, & then it runs off the custom map generated BY your bike, FOR your bike. Seems like the best of both worlds, as long as there isn't a sudden shift in fuel quality or the ratios of atmospheric gases...

Like fotoguzzi said, all LeMans models are long-frame [black]. The color of the frame isn't the key, as Rosso Mandellos had black frames w/ that lovely red finish on the rest of the bike, but they were short-frame models. First V11LM is officially a '02 model, regardless of whether produced/sold in '01 [Dumb motorsports manfs. w/ their model years starting in September... ]

Since they're installed underneath the twist grip, there's no f/x on the wiring: it's all stationary. The left grip will be hotter than the right, naturally, since it only has to x-mit the heat thru one layer of rubber grip, vs. the situation on the right grip, where there is a small air gap, a layer of hard plastic (the throttle's twisty bit), and a layer of rubber grip. The OCD set tend to solder in a small resistor on the left side to balance everything out; I'm sure if you snoop around on the net you'll find someone's opinion on what ohm value is best. The man'f. may have gotten around to making the two sides in different resistances by now to balance things out w/o any external bodging required, but I don't know about that.

Yep, that sounds like Mark! That reminds me, now that I've moved 1/2 hour north of where I was, I should get on up the road to tha LBC to visit old friends & stop by MGC just to say "Hi" & let that stinkin' bird try to eat my fingers again... [seriously unfriendly shop parrot to keep the tire kickers away]

What Foto said... only, it looks like Mark is done being the low price leader for unusual Guzzi bits on eBay; his BIN price on the parts from the V11 are quite a bit higher than the pricing he used to quote. Not that they're unreasonable, I'm just saying that I think he finally caught on to the fact that he was charging too little. Sure wish I could have picked up some of the spare V11 cases when he had them, but I didn't have the money nor space to store them. Would have been cheap ins. against ever holing one of mine tho'!..

Well, yes,they would be, since a slight improvement to the rod ratio isn't going to affect the valve or ignition timing; this isn't a 2smoke, after all! Sorry, I wish I had numbers, I just remember reading the text that went with the nifty cutaway engine fotos of the new square sump engine when the Brevona was announced. That the factory had improved the rod ratio was about all that was said; more attention was paid to the dual-plugged heads [which admittedly, is a more noticeable change than some slightly improved high-rpm power characteristics on an engine w/ a milder cam than the previous generation V11 motor, and moreover wasn't known for turning high rpm to begin with...] It's probably mentioned in Guzziology, but my older edition is in a box somewhere [i've been moving] and I haven't plunked down for the latest ed. of G'ogy 'cause I'm too poor at the moment. I'm very interested in what's listed for the Nuovo HiCam motors, as the newest ed. of G'ogy is supposed to cover them, but since I don't own one [yet] and have no immediate prospects of doing so, my older ed. will still serve my needs [when I unbox it again.]

I doubt it: the 5spd 1100 Spot/Sporti had a different shaft/swingarm length than the later V11 w/ its 6spd box. [Part of the reason Guzzi redesigned the box & went with the unusual design was to get a longer shaft length to reduce the angle on the U-joint and move it outboard so wider tires could be fitted.]

It's the most beautiful bike ever made, followed closely by the '97 Sporti and then by the v11 LeMans for which this sight is named. There were only something like 100 of them brought to the US, so they're rare birds, even tho' they aren't considered a "limited production boutique builder machine" (but should be.) 10 years ago you could still pick them up pretty cheaply [ie, less than their original MSRP], but their prices have been rising sharply the last few years. Sorry, not much else to offer right now, as I'm in the middle of a move and all my Guzzi books are packed away. No, I haven't sold my copy of Greg Field's Guzzi Big Twins yet, altho' if the OOP asking price keeps going higher on Amazon, I may be forced to just on principle that I'm too poor to afford to keep any book that sells for over $100... Good luck on your quest, don't be surprised if you wake up w/ a bump on your head and no memory of what happened to the Daytona RS you'd stumbled onto if you get in the way of my getting one! ;-)

I personally think this falls into the picking the fly sh*t out of the pepper area.. I doubt that these ditch pumps notice a miniscule difference in back pressure from one cylinder to the other. Of course, YMMV, and I've been wrong before. Esp. as the stock crossover is really a pre-muffler, and the "flow restriction" is probably not even measurable. This might be of concern in a real xover like the Stucchi, but the stock box has so much volume that the flow is likely not affected in the least. JMNSHO

Actually, a low-mileage Centauro is likely to be more or less "unmolested," which explains the low mileage per your observation above about how poorly they ran stock. I have memories of an unrelenting series of complaints from an original owner back in the late 90s. He gave up on it after a couple of years; this was before options like a PCIII or Cliff's MyECU became available; I'm sure he wishes he had it back now. The secret is pretty much punting the original P11? ecu and fitting up something modern that can be tinkered with: even the last reflashed eprom by [whassname, his chips were the only ones that came close to getting the Centauros running right] is just a bodge compared to fitting a better ECU, from reports. Best use for a Centauro I can imagine is dumping the execrable body work on ebay & using the funds to buy Airtech Sporti plastic to make up an ersatz Daytona RS. I've only heard of one person doing this, but they were rapturously happy in the end because they didn't have the too tall 1st gear from the Daytona close ratio gearbox, which wasted on that torque monster of a motor anyway... Still love the brutish good looks of the HiCam motor, even if the Nuovo HiCam that Piaggio is putting out now is a much better engineered donk...

Yup, definitely. The distance from the grudge on to the deck of the piston is shorter and I *think* that although the bore remained the same the stoke may of been lengthened but I may of got that wrong. Certainly on the 1100's/1200's the rods are several mm longer than on the V11's and other 1068 motors. Pete When Guzzi announced the updated 2v in the Breva, one of the claims was that it had a revised (improved) rod ratio. Nice to have someone w/ 1st hand experience confirming the rod lengths and piston deck heights are different... The irony being, of course, that the V11 motor was fitted with a cam that would have benefited more from the high rpm properties of a better rod ratio than the one that came in the Breva/Griso mills [softened for later smog regs.]

It happened because you bought an Italian spring of unknown origin. For some reason, only a few countries seem to turn out decent springs that last.

I do understand the logic and how this all happens. My comment was more to the fact that MG is such a small community that I have a bike that (depending on the criteria) reflex three possible model years. I have a friend who works on Lotus 7's and their clones and he can tell you what year the car was built by the welding on the chassis (I have no idea how)it's all such a change from the huge really mass produced bike world Rich No, you have an '02. When it was shipped from the factory, when it was sold, doesn't matter: it's the early model which ended in '02. Get over it. As for your friend being able to tell the difference in Lotusi from the welds, it probably has to do with knowing when the factory changed from stick to MIG to automated welding or something like that. I've seen some perfectly glorious TIG welds that were done manually that looked like they were automated welding, but virtuosos like that are few & far between...

4v valve covers; don't think those would fit on 2v heads. Ad copy says it equates to a 350 ImolaII which is one of the 4v 350s, iirc. Likely just a 1mm overbore cylinder or ? to bring it up to the 400cc "not quite a big bike" cutoff for Japanese licensing regs [do they still do that, or have they changed? The driving test for a bike over 400cc used to be rather insane, something out of a police motor training gymkhana here in the States...]

Dri-Slide. Oily lubricants attract dirt and cause the lock internals to wear. Dri-Slide is moly-graphite in an evaporative carrier solvent. Be careful, anything it touches *will* get stained black.

What a great shot! One of the prettiest bikes ever next to a candidate for one of the ugliest, with a pit cutie keeping score!

Gears need to have smoooth surfaces to mesh & xfer power properly. 3D printing doesn't really get that fine until you're talking megabucks. Wait for it, Weedhoppa: it'll come, it'll come. Maybe not soon, but someday...

Aw crap... Slavomir was one of the people who really made this forum feel like a local hangout full of friends, not some bedlam nuthouse full of strangers like so much of the rest of the interweb... He will be missed.