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That's not really satisfying, is it? Hubert

I assume you have to change the spark advance a bit in this area. This is the best solution I think. The last carburetor cars, already suffering the oncoming environmental laws, were eliminating this low load poping by retarding the spark advance a bit. To go at constant speed you had to open the throttle a bit more so the engine came out of this difficult to tune area. Using the proper tools you can do this yourself, without sending it to TLM (and you can get some money for your PCIII by the way). What I found working also is to give more advance, albeit this can lead to some anoying to'n fro what sometimes must be interrupted with a short clutch feathering. Changing the advance gives "instant action", the attempt to drown every possible fault easily leads into frustration. Times are a'changing Hubert

Mike, that's a bit of what I meant in one of my previous posts talking about this so generously enlarged S/A wich can be seen on the Mike Rich pistons. I think that what you've written above together with the fact that a however perfectly balanced squish gap is effective only for a very small amount of crank degrees could lead to more problems instead of gain remarkable advantages. At least if you consider what efforts have to be made (milling the cylinders, buy expensive pistons, time and so on). My concern is that the MR-pistons may give a perfectly compact combustion chamber, but only exactly at TDC. The crankshaft moves on and "suddenly" all around this perfect chamber deep and relatively cold "slots" or pockets are being opened and they possibly spoil a lot of what has begun so promissingly. Hubert

Paranoia?!? Hubert

The two forks at the center or connecting shaft must lay in the same plane. That's all you have to look for. You must be able to "bend" the shaft to a flat Z-like pattern, no 3D-object must occure, then you have done it right. Isn't there any engraved marking on yours' Hubert

Every BMW until the don't know what last models had only one single U-Joint in the drive train. They probably just didn't care about the sinusoidal downsides of this concept and the bikes are running happy 'till today. Anyway, here one should align properly the two halves, of course. On mine are no white markings left, but the facory (whichever) was so friendly to engrave an arrow in each part. Could be that this marking is hidden under the white sign. Hubert

I was always asking me why all the US Guzzis seem to be so prone to pinging. Now, what if they haven't sold you any squish area at all? Hubert

Regardless what in the end may come up as the reason for your actual problems: if your TPS now is set correctly according to the description Moto Guzzi gives and wich Jeff has proofen to be correct, then let your fingers off from the TPS. That's not written in bolt because I think I should tell exactly you what to do or not. It's because this is an adjustment done "once", comparable to the (fixed) adjustment of the camshaft, valve clearance or if you want the chassis geometrie. Everything else may sound in a certain way "technical sophisticated" but is, well, not really common technical sense. If you feel there may be something wrong with your TPS or its setting then check it according to what Jeff was so friendly to post on the mentioned site. Never just loosen the screws and turn the TPS 'till you think your engine runs better. Else you'll loose every solid ground this way and in the end possibly end up with the third TPS. Fiddling with the TPS and selling this as a "secret solution" is unprofessional. ----------------------------------- According to your last post it seems as if you are either already well supported or you personally know well what to do and how things work. As Dave already has mentioned: why don't you just modify the specific area where the hickups appears? While working on my map I found that using an O2 probe/target to solve such transition problems is not 100% satisfying. Opening throttle is such a transition problem. I'd probably not so much enrichen the cells the engine passes but more those where the transition starts, in order to underlay some food for the trip where carbs relay on the acceleration pump. If the PCIII allows it to overlay its own temperature correction map above the ECU one, than probably this is a point where your work could start also. If the overall behaviour of the Guzzi is satisfying then a sensor is probably not the reason for the coughing. Also, the engine is new, so the timing chain and the shafts should not already suffer excessive wear what also could be a reason for such things. Finally, to come to an end now (as the hollydays do also), have you compared it with another bike? That's not my daily business, so please take it as my Hubert

Ratchet, what shall I say? I think I'll just beleave it this way. Funny enough, indeed. Probably the -/00 stands for the two US-wholes. Hubert

Yeah somehow, but what about his funny radiators under the chin? Does Papa know all about her what he should know? Hubert

When I remember right then the proper idle setting is 550, at least for the Titanium ecu. At 475 you are running it too lean then. How many miles do you have on your Coppa Italia? The TPS might be cheap, but its an industrialy manufactured product, manufactured and sold by well known and reputated companies in large quantities. I think it's quite unlikely that you can get 2 of them in such a short period and both are already corrupt when new! I suppose it's more a problem on your dealer's side. You may have noticed, I have 60000 km plus on the clock now, that's around 40000 miles. I'm not amused about the TPS failure, but still it's quite a distance for a leisure product. A motorcycle nowadays is technically spoken just a leisure product. Built for quick fun, colorfull and cheap. I feel sorry about that, but it seems to be a fact. There is a cartoon from MotoMania: One fellow kneeing besides his opened Laverda engine, the other one standing besides him. "I have never had my knee down to the street. And you?" "Me? Always!" Hubert

The most challenging thing for a potentiometric TPS is the so called Ditter-Test. Very small movements for a long time. This kills most products actually available. I never had a problem while autotuning the map. The software is so smooth that it always works, regardless whether I make minor "mini-twists" or not. Trying to keep the throttle rock steady for some time can lead to a damned dumb feeling in the right hand. And it prevents me from making suitable outlines for my cornering. Hubert

Only on first sight. The TPS is of course sealed! What you saw is just the opening for the throttle shaft. To others I'd strongly recommend not to 'seal' the mentioned gap. Water, cleaning fluids, gasolin e.a. will find their way inside, they have time for this, but they will never again find a way out! Hubert

Jeff, thank you for this very clearly and understandable written statement. Right on the spot. I think starting at 3% is important to keep the output above zero. The PF4C graph shows the tolerances. 1% is already lost for manufacturing tolerances, then there are of course tolerances applied to the input voltage, tolerances in the total assembly TPS to shaft and so on. I'd say 3% is already right on the edge. These potentiometric sensors normaly dont have probems with linearity because of being used at the end or beginning of their range. The resistance should be a function of homogeneity, thickness and width of the printed resistive paste. What you have said about the coherence between the steep output curve and the narrow TP steps in the map at low opening angles makes absolutely sense. I'd take this as a forward pass and herefrom deduce an urgent need to adjust the TPS exactly to the values the book tells us. Otherwise there is a very good chance that the ECU might not fall back in idle mode for instance or do other unexpected things. The TP rows are staggered like this: 2° - 3.67° - 4.18° - 5.18° - 6.77° - 8.16° ... I think this could lead back to where the topic started: a slight glitch while adjusting the TPS could quite easily lead to glitches while slowly opening the throttle. Hubert

Here is a picture from the worn track: If you follow the leads you can also recognise at wich point the slope changes. And you can see the "510" of course. Hubert

Thanks for outcoming, Jeff. This picture is most interesting for me, as my TPS is dead (resistor layer rubbed through) and I'm actually using a DIY version based on a GM pot. I still hesitate to buy a new one. It costs just too much. You have the electrical spec from Marelli. This shows what they purchase from CTS, not that MM would make it itself. Also Harley for sure is buying it there (albeit I've never seen one, but if the housing is the same...). An angled output line is quite seldom when used as a TPS. The reason is probably that normaly a TPS is based on a redundand system because of safety reasons. A car TPS nowadays is in most cases combined with a throttle actuator, so a failure in the sensor can have surprising effects. What I meant with ridiculous specification was for the mechanical part of it. One million cycles as guaranteed by CTS is a b'y joke. 14 millions should be the minimum. I don't want to blame CTS for that, they are producing for higher standards as well. Its more the fact that Guzzi (and Harley) uses such a cheap version. Thanks again Hubert PS: Recently I found these lines on an Italian site: "Adesso lo so venderò questa merda di moto, manderò a fanculo questa fabbrica di Mandello che vende illusioni e rottami e fa pagare un pezzettino di plastica 200 euro, per lo meno la parte di me che ha sopportato i soprusi e l'arroganza di certi stronzi sarà libera e felice per sempre..."

I thought the speed-o-meter looks as if it must get also opened sooner or later because of the missaligned digits. Then this pointer will get its new coat. If I do it this winter I have a good chance that the colors will match. While I was at it I changed the bulbs to green ones (laquered them) to add some more color. The all black times I let behind me. On my previous bikes everything looking a bit rotten got a black repaint, but now, getting older, at least the bike should keep as much as possible of it's shinyness. Hubert

A picture of the above mentioned engine: Also the sump shows some interesting details. Don't get me wrong: that's the brand I'd buy only in fourth or fifth place. Not that it was of nonsufficient quality, it's just a bit to chilling. Hubert

That's how a freshly painted needle looks:

Some might have been waiting for the promissed pictures. Here they come: The conductor springs. The coil PCB Back of PCB PCB roughly laid onto the mechanic unit By turning the small poti one can adjust the tach. Maybe that a drilled hole will give access to it. You see, really nothing that should brake or go wrong besides the springs that are looking to be quite prone to vibration induced damage. Hubert

Your Mom in law is ok then? At least one sorrow less... Hubert

That's why they make sense mostly above 50/60 mph. Hubert

As I said, these pictures may lie, but to me it seems as if the idea of MR was to follow the head contour as close as possible, so giving him the chance to reach a high CR and a well cut down dome. That's nothing more but a greatly increased squish area. What is better or worse? What we call squish area is in fact just a result of the attempt to rise the CR. It somehow blows the gas away from the cylinder walls, but without any resulting swirl to fasten the burning front, without any target as for instance the spark plug could be one. Consider also that, as Pete already has said, the direction of inlet and outlet ducts are everything else but optimal and then you will hopefully not expect too much of all this squish fiddling. That's why I mentioned the 4V BMW. It's just the different system that makes the advantage possible. And even they have recognised that 122 HP is already right on the edge, just because they suffer the same restrictions as Guzzi when it comes to optimising the porting directions. It looks identical to the Guzzi 4V engines. Two high camshafts, chain driven here. Could it be that Guzzi had this solution first? A serious dealer/mechanic should tell his customers that of all this very expensive stuff and time max. 30% will be effective, compared to every 08/15 4V-Jap bike, the rest is just for the good feeling to have well supported him and to have well expensive parts built in. And what about the difference between static/theoretical and dynamic/effective CR? Did anyone mention it already? What if someone says that such an expensive high CR piston reduces the effective CR by reducing the delivered amount of fresh gas under certain conditions? Hubert

Thanks Dave. I meant pin, of course. The Mike Rich version I do like better than the FBFs, but all the pictures are taken from a different angle, so it's hard to tell. And you know, I like the Guzzis most! The cut dome of the MRs surely is a good idea, but I don't think that the so greatly enlarged squish area is an idea as good as the one before. Assumed that I interpret the picture right. I'm not sure about it, but I expect that this causes a very sharp pin in a thought compression over stroke curve. The ignition happens before TDC, then this CR peak is added (when the squish area closes) and immediately after that the CR again shows a significant drop when the squish area opens again. BTW, the actual BMW R1200S 4-V engine has a CR of 12.5! Without any piston dome. 122 HP straight out of the factory. Hubert

Interesting! Thank you for the pictures. Do you have any numbers about the weight of these beauties? What is the recommended play between piston and bore in comparison to the OEM part? Do they come complete with the bolt? The bolt will probably fit 1/1 into the upper end of the rod, won't it? Thanks for any answers Hubert