motoguzznix

I think this will always be the case as the rear of a Guzzi is very heavy because of the rear drive unit. Unsprung masses are in a very bad relation to the rear axle weight compared to a modern chain driven sports bike. The front can be made as good as any machine using the right components. I put' in some effort in the Marzocchi fork with sag adjustment, but the results didn't encourage me to go further forward in this direction. The ride height was ok then, but the suspension is not sensible when going over short bumps. So I bought Öhlins front and rear from HMB, but could not yet afford the time to convert my 2000 V11. I agree with Gary cheek as the short wheel base V11 is much more fun to ride than the later model, so I hope to get the most out of it with the addition of Öhlins.

I did not read the complete thread, but I will tell you my solution of the problem: Simply install 2 further relays for the high and low beam. There are sockets available to be added to the front section of the original relay block. The seat has to get a cutout for the 2 relays. + for the beam is taken from the starter relay input, 2 wires from the light switch will activate the relays, 2 x 2,5mm wires from the relays will lead to the high and low beam. A ground wire for each relay is needed, ready. The most effort is the installation of 4 wires from the relay block to the beam connector with the connectors necessary. The advantages are: This subtracts the current of the beam from the starter and light relay. the beam will still go off when starting the beam current is not in the light switch (big advantage) therefore highest possible tension on the beam contacts A horn and flasher relay is not necessary, as the switch and the relays involved will withstand the very occsional activation. Another possiblity for the + would be to use the free fuse in the fuse block with a fat 2,5 mm wire to the beam relays.

Almost good; So, with a chamber diameter of 81 mm and a bore of 92 mm we get 22,4 % squish area....

Mike This sketch is the stock head before I did any mods. At the time of dismounting the heads, I removed only 0,5 mm from the heads as this was enough to get the target CR. When removing further 0,5 mm from the head and using a thinner 1,2 mm head gasket as intended (instead of the then unsed 1,6 mm), the valve pockets for the intake valves should be deeper to have enough clearence. The time for the engine assembly was limited, so I put it together at this state. This will be done when the heads come off next time when I replace valves and guides. Even with the ring area too small for effective squish, there might be reduced pinging as the ring around the periphery with then only 1 mm height will contain a too small amount of gas to burn from itself. 30 % of the diameter would be a ring of 13,8 mm around the bore. This is hardly possible with the Guzzi engine. In case you really would find some engineering drawings of the V11 Engine, I would not trust in the fact that the really produced engines will follow these drawings.

Ratchet Here is the sketch with my measurements from the head/piston design: Again, this is a scetch, not an engineering drawing! There is only 1 mm of possible squish with the original head. When you milll off 1 mm from the head, the squish band will increase to 5.5mm, which makes a noticable difference. Hubert, the engineers at Guzzi aren't holy people. They make faults like everyone of us. You have to take into account that the engineering department at Guzzi worked for many years on a very reduced scale. I remember the Lario design, where the valve train/cam/spring calculations were actually wrong. Together with the poor material quality the heads and cams failed in almost every bike. A development like the Breva/Griso engine/drivetrain would never have been possible at that level of engineering manpower. Only the collaboration with the Aprilia people could create an engine that meets the Euro3 homologation. The V11 design is a good working design, when everything is assembled perfect, which not always occurs at the Guzzi factory. So pinging is a problem on many of these bikes, mine pings, Davids pings an others too. This is what I try to get right on my own engine. Maybe there was a piston design like the MR piston intended for these heads, but not realised in the production due to availability. Who knows?

Ratchet I took some measurement from the head design when they were off, I will post this soon. Mike, Hubert, Skeeve The combustion chamber shape resulting from that head design is not favorable, as shown in the following sketch: These big pockets let me doubt about the serious work in the factory on the combustion chamber shape. Previous Guzzi heads were not of that design and used a large squish area.

Ratchet The shape of the V11 cylinder head is different to that on the picture sent by brucev11. I tried to draw that into the picture above. As you can see, the breva has the classic hemi with squish again. The V11 heads have a conical shape in the area from the cylinder bore to the hemispherical chamber. So there is only a small area of approx. 1 - 2 mm squish remaining on the ouside of the combustion chamber. Squish on my V11 was at 1,7 mm. You have to mill approx. 1mm off the heads to make the conical area disappear. Then the hemi area blends into the then larger squish area, which at my opinion makes a better combustion chamber design. When you further machine approx. 0,5 mm from the cylinders to bring the pistons to the top, you are 1,5 mm shorter with head and cylinders, so the pushrods should be shortened by the same amount, to prevent the valve train geometry getting asymmetric. Furthermore, the compression ratio raises and the valves come nearer to the pistons. Valve clearence has to be taken into account and the pockets in the pistons might have to be deeper. I would look for a CR not too much above 10:1 without twin spark. Unfortunately I am only half that way with my V11, but when I pull off my heads next time, all that will be done.

Pete setting the squish correctly is always a good idea. When I put' new cylinders on my good old Le Mans 2, the pistons in the new gilardonis were 0,7 mm below the top. Add now an aftermarket gasket with approx 1,5mm when compressed, the squish thickness is 2.2 mm! Thats very far from the truth. The example stated before won't cause any damage on the engine, but this is one of the reasons why "straight bolt ons" do not exist any more in my book. When something does not work in my engine that was "Bolt on" then I am responsible for that, not the manufacturer!

Ratchet Unfortunately, at the time of assembling the engine, I could only get some gaskets with 1,7 mm thickness, so I can't tell you the truth. With the right 1.2 mm gaskets the CR will raise from now 9.6 to 10.0 which was my target when I started all that work. I had to complete my bike for a 4day trip to Italy with some friends which was fixed a long time ago, so I didn't want to wait any longer. The guys with the japanbikes shall see that a Guzzi always runs.... So I drove the bike since then for 5500 km with no complaints. I will rectify this when I dismount the heads next time. At the same time I will drop in new valves of better (carbon coated) quality and guides. The valve seats are of good quality and will only get a very slight rework. So far my intentions. Due to the fact that I have to build a new house for my family (with a big workshop for me) this and next year, the progress on my Guzzis is minor these days. P.S.: Squish clearence should be in the area of 1 mm according the book "schnelle Motoren seziert und frisiert" written by Helmut Hütten" which is the only source I could find in a Book. A 1.2 mm stock gasket with the pistons decked on the cylinder gasket surface seems the only way to come near that.

That was really new for me, thanks for rectifieing that. I really thought of the old Fiat... am I that old??

Ratchet I am one of the guys who posted about the poor quality of the cylinder head machining and valves. Quoted a post of mine on the subject: The reason for disassembling my (almost) perfect running 9000 km engine and the work done ist documented here: Unpacking the cans I am sure my engine would have lasted 50 - 100 000 km with the cylinder heads in that condition. The only concern with some risk of failure is the excentrically drilled valve guide that brings some side load on the valve stem and a bending force on the valve disk with the possible cracking of the disk. But this occurs only on rare occasions on the big block Guzzis, while very common on the small blocks V35 - V75. Fixing that sealing problem of the valves reequiered a lot of valve-seat-grinding by hand. If you assemble the engine with new gaskets, pay attention on the thickness of the gaskets: I have seen gaskets from 1,2 to 1,7 mm, being the original ones the thinnest. With thicker gaskets the squeeze area of the combustion chamber gets wider with the risk of increased pinging. Machining the cylinders to get the pistons comletely to the top of the bore at TDC is also a good idea (smaller squish area). Raises the CR as a bonus. Mine were 0,45 mm below the gasket surface. And check valve clearence before reassembling. I like the things to be good but not necessarily perfect as I'm an experienced mechanic and I drive Guzzis since 23 years now. But I wouldn't have disassembled my engine if the engine vibrations would not have been so severe. I balanced the crankshaft and reassembled the engine with all my knowledge and care. Almost everything on the V11 was fine but the head quality was really diappointing for me, as you can read above. I do not recommend everyone to disassemble a good running motorcycle, but when oil consumption and valve train noise begin to increase, a look to the heads is never wrong, and the effort on a Guzzi to fix these things isn't too big....

guzzista Coils from an old Fiat won't work with the V11 Marelli 1.5M ECU. These only work with an ignition system controlled by contact breakers. You need to have the correct resistance in the primary circuit of the coils. Otherwise the spark will be poor to zero or the ECU ignition circuit will give up, which would be the end of your ECU. Additionnally the spark map has to be remapped to keep the ignition advance below approx. 28°.

HMB has also a range of uprated cams for Guzzis. If you buy one of these, do not use the Kit with springs and valve spring retainers, as the V11 has good parts built in in the factory. Use 8206 for more torque ore 7906 for more power.

I read the ECU ID code from my 2000 and my friends 2003 V11 naked (no catalyst) by using the ultimap software Its definitely the same: 3D02VS9F I suppose all models prior to the catalyst equipped bikes have the same mapping. I also believe that setting the fuel trim will adress the the lean off-idle condition. A dealer with the Axone tester or a tuner with the Ultimap software are able to do the adjustment. Go for 3 - 3,5 % CO at idle, that should work well for a near standard bike.

Very interesting topic The frame topic is focused on ride height now, so I will contribute a input to that: My KR fork seems to be in line with Huberts and Nocs: I always found the front too hard (75 kg rider). I do not remember exactly the sag numbers I took some years ago, but on the front my figures were less than mentioned above. So I shortened the spacer tubes slightly to get the right numbers. But that was not the main problem with the fork: The damping tube inside the left leg (compression) showed three holes drilled in the lower area, two of them drilled in opposed position. So the damping piston travels down half of its way and every damping effect of the damping valve is bypassed via the 3 holes. When you go over a hard bump, the fork moves down undamped very rapidly until the piston has passed the holes and then full damping occurs due to the high speed movement of the fork. This behavior makes a very harsh and unpleasant ride. I ended up by closing the holes with a sleeve. The adjustment srews are completely open on both sides. Now the fork works much better, but still not perfect. Especially when braking the front moves down in a more controlled manner. Not perfect is the reaction of the fork on small bumps, it feels not sensible. The rebound damping also works sightly during the compression stroke, thats not desirable. With a more sensible front, a lot of influences would not be transmitted into the frame contributing to an unstable driving behavior of the vehicle. I am thinking about Öhlins on the front......

Martin did you already check the AC-voltage at the 2 yellow cables out of the alternator? Should be in the area of 40 to 80 V with the engine running, climbing with rising engine rpm. When you measure some AC-voltage here, your alternator is ok and the problem seems to be the regulator. If necessary, I would not pay an original regulator as this seems to be of inferior quality an elevated cost. Dlaing has a source for an aftermarket one in US. In Germany, Bike Affairs Bredenbek are a good source for an Aftermarket regulator at 82 €. EMail jaeger-volk@t-online.de This regulator can be trimmed to the correct voltage by using a very small screwdriver, which is a good detail. I still used there regulator and it works fine. Good luck

Hello David I measured mine and got also 10 V at F1. The current along the fuse was 0,0075 A which is one tenth of yours. Drawing 0,072 A out of the battery sums up to 12 Ah in one week, so the battery should be completely empty. According to this, my bikes battery should be empty within ten weeks, which really occurs. Better than yours, but still not good. There is some fault in the electrics to be detected. Does this current flow via the ECU ground cable? Then a possible solution would be to switch the ground cable by a relay that is activated by the plus at the ignition switch. Does not cure the problem but prevents the draining of the battery.

Hello Pierre I would not bother with the Breva ignition map! This bike is able to meet the emission requierements of Euro 3 what a V11 will never. And your tuned one at least. So the ignition advance of the Breva is taylored for very different requierements. I would start with a stock advance curve and reduce the maximum advance at full throttle to 26 to 28 degrees. At part throttle, where the advance is even bigger, I would also reduce by 10 to 15 Percents. This should allow you to start on the dyno, where the timing can be optimized.

I think this is really bad! I agree with James the Dyno guy. This bike lost about 10 HP in the middle of the rev range where you really can use it! I wouldn't accept a result like this performing a tuning modification. I also like the looks of such a center box exhaust, but this dyno result moves it from my list! The V11 isn't really overpowered, so spending a lot of money to loose considerable power and torque is not the route to go! Is there nobody out who can make the QuatD silencer work?

good idea the carillos... The piston kit in the link seems not to be serious as they fit to Calis and V11s. This is not possible as the combustion chamber shape is different on these bikes. Ernst

Hello Tell me one reason why this 2*35W HID light with 2 very small reflectors should put out a brighter light like the 55/60 W with an almost 8" reflector on a 2000 V11? Putting in a 90/100 W bulb is a bad idea without additionnal relays for the beam. The switchgear will soon be smoking.... The relays also help keeping the voltage in the 14 V range. I mounted two relays by using the stock sockets added at the front of the relay block. The underside of the seat needs a small cutout for relay clearance. From the relays to the headlight I used 2*2,5 sqmm wire. Ernst

Hello you all modifiers had anyone of you taken the weight of the new pistons? The stock pistons of my MY 2000 weighted 500 g with the rings on + 106,5 g the pin which is both very heavy. The piston weight has big influence on the crank balancing. A perfectly balanced engine will run worse with a different pistón weight. Best would be a lighter piston with the crank balanced to match. I would be interested in the weight as this might give me the opportunity to choose a lighter piston. Ernst

Hello Pierre I think it is a good idea to swap to the Centauro throttle bodies at your state of tune. I would use the complete centauro setup - intake manifold, rubber and throttle body and the connecting parts to the air filter. When all that fits into the cantauro in the same frame, the swap sould be straightforward. Modifying the intake manifolds of the V11 should not be possible as these have too thin walls.

Milling 20 grams out of a piston seems to me a lethal dose. A max of 5 g to bring the pistons on the same weight is practical, but 20 g will kill most pistons (ecxcept cast iron ones from pre WW1). And as I understood in this case, the new pistons are lighter, so you should add 20 g to every piston to get the same balancing factor as before. To balance the crank, you have to calculate which master weight you have to apply to the crank pin to get it right. For a 90° V-engine you take the complete bottom weight of the rods (you have to weigh bottom and top of the rod) which represent the rotating mass of the engine parts. The reciproating mass ist represented by the Piston with rings and pin and the top of the rod. The theoretical ideal is to take 50% of these masses and add it to the rotating mass. This is the amount of weight to be applied on the crank pin. Balancing then can be done on an expansive machine or statically like a tire is balanced. I removed the material with a small angle grinder with grinding paper. You have to be bloody careful not to distroy the main bearings. Why in practice the balancing factor is above the 50 % depends on the oil which is on the crank while the engine is running, and there is oil inside the crank pin too. This condition is not when the crank is outside the engine to balance it. When you take care of this, the balancing factor gets higher. And the amount of oil on the crank depends on the rpm too, this explains for me the different balancing factors like Pierre explained for engines with different rpm targets. On my V11 the crankshaft lost approx 50 g to get the 52,5 % balancing factor. This does not mean the the imbalance of the crank was 50 g, as you often cannot take away material where it is needed. Mostly you have to take away from the crank pin side and not the opposite side where the counterweight is located. And the balancing was pretty successsfol as the engine now runs a lot smoother than before.

Pierre When the crankshaft was balanced with the heavier stock pistons, a decrease in weight would change the balancing of the engine. Vibrations will increase, despite the fact the pistons are lighter. A 90 ° V engine has theoretically a very ideal balancing when 50 % of the oscillating weight is calculated for the master weight. In this case only horizontal forces remain. As more the balancing gets away from ideal, the more horizontal and vertical forces occur. I was balancing the crankshaft of my 2000 V11 a year ago due to the very severe engine vibrations. I calculated the master weight for the 500g piston + 106,5 g pin to 1832 g (balancing 52,5 % of the piston weight). If I would reduce the piston weight by 20 g, the master weight on the crank pin would be reduced to 1811 g. This is a difference of 1,2 % in the weight, hard to say how much this would worsen the engine vibration behavior. Normally reduced weight is always a goal for oscillating parts in an engine, thus the best solution would be to change the crankshaft balancing for the lihgter pistons. If the engine is already out of the frame, this would be my route to go.