GuzziMoto

Dan M, so when you said "An open to the atmosphere thermistor can read the surrounding air immediately" you did in fact mean the sensor was vented to outside air? (as in the atmosphere we breathe?). I don't think that is what you meant, but if in fact you "did not misspeak. I said what I meant" then so be it. Not a normal use of the word, but I guess in your world the responsibility is on the reader to understand what you meant and not the speaker to pick the most appropriate words. The reference to the body of the stock sensor was in response to statements made by people to the effect that the stock sensor body acted like some sort of magical heat trap (heat goes in but it don't come out) that actually causes the sensor to heat up higher then the temp of the engine (those with superior grasps of thermodynamics no doubt). Due to the fact that the sensor tip is actually connected to the sensor body, yes some heat that goes into the sensor tip would end up in the sensor body.Some of that heat may end up flowing back into the sensor tip if it ends up being cooler then the sensor body but the rest of it would just radiate out the exposed part of the sensor body to the atmosphere ( that's the outside atmosphere, not the inside atmosphere). I do not feel this is an important aspect of the stock sensor, but to those who think the mass of the stock sensor is an issue it is relevant. dlaing has actually been fairly interested in RH's concept, and while he does question things when they don't add up he is clearly not against the idea completely. But to me it comes down to this. If you want to do it fine. But if you want to convince me that air transfers heat better then metal, you're going to have to do a better job of choosing your words then you have done so far. In fact, why don't we both hold our fingers 1 inch from a blow torch flame. I will fill that 1 inch with air and you can fill it with metal and no air. Yes air can change temp faster then metal, but no it does not conduct heat even remotely as well. Any 3rd grader could tell you that. You and RH act like people who don't agree with you are morons or something. But then you two make assumptions based on opinion, treat it like fact, and wrap it in B.S. If your bike ran lean when it got hot, got worse when you put heat transfer paste in between the sensor tip and the head, and that went away when you used an air temp sensor to measure the air gap temp instead of the head temp, well if you can't figure that one out I guess it is not my job to help you understand (because in all likelyhood you do not want to understand).

I have NEVER said the stock sensor reads temp from the exposed brass part of it. I did say that part of the sensor was exposed to the outside air and could (does) radiate heat to the outside air. But you did imply the sensor RH was using was vented to outside air so that it could better measure the temp of the air. I would guess that you just misspoke and that it was not what you meant. But since you accuse me of contradicting myself and slammed dlaing for having "a strong opinion about a device you don't know much about", I have no sympathy for you. You posted incorrect information and then slammed people when you were called on it instead of manning up and clarifying what you meant to say in a polite manor. Everybody makes mistakes, what says a lot about you is how you act when YOU make mistakes. Not only do I have a decent grasp of how thermistors work ( I actually work with them), but I have two Guzzis with the stock sensors (the new Guzzis use the same "bad" sensor as the V11s) and both bikes work quite well. This does not make me unique or special, quite the contrary, many Guzzis with the stock sensors work fine. Again, if RH or you or anybody else chooses to alter the stock cylider head temp signal (or you could do the same with the air temp sensor signal, or TPS, whatever) that is fine. Just please don't try to pass it off as anything other then what it is. You are not improving the accuracy. Everything that has been posted says you are decreasing the accuracy in an attempt to richen up the fuel mixture. Knock yourself out, but be honest about it.

So, Dan M. When you said "An open to the atmosphere thermistor can read the surrounding air immediately without having to heat and cool the brass encasement" you didn't mean "atmosphere" you meant the air inside the sensor set up, which sounds a lot like "atmosphere" but is spelled slightly differently.

And I thought we were trying to measure cylinder head temp accurately. Strange though. In the pics he posted I recall seeing a black plastic piece with three holes, one in each end connecting somewhere in the middle and one for a set screw for the metal rod that was supposed to transfer heat from the cylinder to air inside the plastic piece. If it is vented to outside air it makes even less sense, but I don't think that is the case.

The tip of the sensor is inside the plastic housing. The body of the sensor is exposed to air and easily visable. It is the brass part at the end of the plastic part. Yes it was designed to measure coolant temp and not air temp. But since we are measuring cylinder head temp and not air temp that is somewhat beside the point. There is an air gap between the sensor tip and the head stock. Any gap here will cause lag in the reading and lower the reading. But the stock gap is very small. None the less, some people experience that their bike runs rich for too long after starting and consequently gets poor mileage. It has been suggested that the gap can cause this and that a fix is to put some sort of heat transfer goo in the gap. This will decrease the lag IN BOTH DIRECTIONS and reduce the gap between measured temp and actual temp. If your bike does not have this issue there is no reason to add the goo and doing so could spoil the way your bike runs if it is already border line lean. As far as "All major manufacturers use a plastic body, open thermistor when reading air temp.", this is probably true but since we are trying to measure cylinder head temp and no manufacturer I am aware of uses a plastic air temp sensor to do this I don't see what that has to do with it. Reading the air temp right next to the cylinder temp is not the same thing as measuring the cylinder head temp. But that is not that big a deal either. What it comes down to is RH is tricking his ECU into adding more fuel by feeding it a LESS ACCURATE cylinder temp reading. I don't have a problem with anybody doing something like that (although it is hack) but when they start talking about it improving the accuracy of the stock sensor or fixing a problem (that their bike doesn't actually have) I gotta say B.S. "Mine developed one on very hot days only after adding goo to the factory sensor. This tells me something and it is not too hard to figure out." You would think, but it appears not. When you added goo you decreased the lag and decreased the gap between measured and actual. The goo would improve heat flow in both directions, helping the sensor heat up AND cool down. Some here seem to think the goo would only help the sensor heat up, and even going so far as to say it could cause the sensor to heat up to a temp HIGHER then the cylinder head. This is not possible. What your temp sensor goo experience told me was that your bike was fueled correctly with the lower temp reading that it had stock and when you added go and decreased that temp difference and got a higher, more accurate reading it leaned the bike out accordingly causing you bike to not run as well. Does this mean there is a problem with the sensor, well no. You only had a problem after you changed the configuration. Besides, the sensor only measures temp. If your bike is running lean and your temp sensor is reading the temp correctly but if you alter that reading to read lower so the ECU richens up the mixture does that mean the temp sensor was the cause of the problem? Not in the real world.

Even if the temp sensor had NO cooling air (which is not true, it gets cooling air) it would still have the same heat path available to it that the heat flowed into the sensor on, the point where it makes contact with the head (or almost contact if you have an air gap). This path is a two way street, heat can flow one way just as fast as the other. It cannot heat up faster then it can cool down. Neither of my Guzzis has had an issue with the temp sensor reading higher then it should and leaning out the mixture. RH has not even taken readings to show this is happening. He appears to be working off the assumption that since fudging the temp sensor reading to read lower makes his bike run better that the problem (that his bike does not have) MUST be with the temp sensor. This is a fools assumption. If he or anybody else wants to ride that train, well, you cant save people from themselves.

Yes, you go on about things you have no knowledge OR experience with (like the "dangers" and "stupidity" of upgrading your brakes) and I'm the ignorant one. You are pathetic. And as for the "quote", do you see any quotation marks on it because I don't. Therefore it is NOT a quote. Do you have a reading comprehension problem? I thought that was what everybody else had. As for RHs temp sensor bodge, it is not a new idea to fudge the temp sensor to trick the ECU into supplying more fuel. In fact, you can buy a device for our bikes that does just that. But not many mechanically inclined people (none I know personally) will resort to such crude things. It is a hack job. Only fitting then that RH runs with it and tells everyboby that he has corrected a problem that he did not have and that he has improved on the "shortcomings" of a temp sensor that has worked fine for most people and continues to be used with no problems on a lot of bikes. Yes, if your bike runs lean and you fudge the temp sensor signal to read lower then it should the ECU will richen up the mixture. But making the leap from there to assuming the root cause of the problem (that your bike doesn't have) is the sensor (with NO evidence to support that assertation) and then lecture those that don't make that leap of faith with you as ignorant, well typing skills are not a reflection of intelligence is all I can say. What you did was of interest until you took it beyond what it is, a hack.

The damper should have play but not in the direction of travel. It should be loose side to side at the frame mount, but it should not have any play in the direction of motion.

If I understand you correctly, the clutch is not engaging until you have released the lever completely. This is not typically something that bleeding will help. Bleeding tends to help when the clutch does not disengage completely. It sounds like you have worn plates or something mis-adjusted.

Confucious says.....because you get the result you wanted does not mean you understand why. If the o.e. sensor has such "shortcomings", why do most peoples bikes work fine with them? And how is it the o.e. sensor can heat up quick enough but can't cool down fast enough? In fact, the notion that the sensor can not cool down as fast as the cylinder head (which has much more mass AND a source of heat) is laughable. You replaced a water temp sensor, that was measuring the temp of a metal object with way more mass then the sensor, with an air temp sensor that has even less mass then the o.e. sensor but does not make ANY direct contact with the metal object. You got a signal sent to the ecu that corresponds to a lower temp (and therefore richer fuel mixture) and equate this to the difference in mass (but not the lack of contact or difference in sensor output?) And you think everybody else is in the dark?

I'm happy with my Griso 1100 but I feel I would be happier with a 1200. If some is good, more must be better. Actually, I am a little disappointed in the fact that my wifes V11 is stronger then my newer Griso1100. When the wifes bike is faster then mine, something is wrong.

Sorry, but I think you focused on the wrong aspects of my reply. I doubt you have ANY serious problem. These bikes WILL make bad sounding noises if you set the idle too low. Yes it will be more noticeable in a cold confined garage. Stock tachs are usually NOT very accurate on most bikes, not just Guzzis. Yamaha even got into trouble with its R6 a while back over its tach. Guzzi motors are very reliable mechanically. Don't jump to negative conclusions so fast. Start with the basics. Ste your idle, check your valve lash, etc. Then enjoy the ride.

Clutch hub splines or other transmission bits are a possibilty. Also a loose timing chain or weak timing chain tensioner spring. But if it's quiet above 1200 - 1400 rpm I would just set the idle there. (Remember the tach may be off by 200 rpm easily).

What rpm do you have it idling at? I don't think Guzzi motors like to idle lower then 1200 rpm. They get noisey below that. I would agree that if it is a rod knock it would probably not go away at slightly higher revs. What rpm does it knock at and what rpm does it go quiet?

When you put it that way it makes perfect sense.

Thanks Pete. Good to know.

Heck, I was getting over 70 mpg out of a stock Buell Blast. H-D's seem to have a much more effiecent combustion chamber then Guzzi does.

See, that's why I read stuff like this. If it weren't for reading this thread I wouldn't know that thermal mass and thermal inertia are unrelated, that putting a heat sink on a temp sensor increases its accuracy, that an air temp sensor is a better choice for measuring cylinder head temp then a water temp sensor, that a water temp sensorthat weighs less then a ounce or two has more thermal inertia then a cylinder head, and that the Easter Bunny is real. I take being insulted by RH as a good thing. It means I'm on the right side.

I certainly would not have put this much into "fixing" a problem that did not exist. But then , when I read things like; "Its considerable inherent property of thermal inertia means that the sensor body takes time to heat up and cool down.", "The temperature at the sensor body lags behind the temp of the cylinder head (in either direction) until heat can flow through the sensor probe (again in either direction) as it seeks equilibrium between head and sensor body.", "I beleive there are times when the head does cool faster than the OE sensor body,", "that being the heat flow problem and thermal inertia of the relatively high-mass OE sensor body", "(Again) taking measurements OVER TIME would be the entire thrust of my observation of the THERMAL INERTIA and lag-time problem with the sensor, as thoroughly presented and discussed in previous analysis." I tend to think that someone is saying that the problem with the OE sensor is that it has too much thermal inertia, and in this case, "too much" would imply that it has more then the cylinder head so that it cannot change temp as quickly as the cylinder head can.

That was funny. RH telling someone else that THEY have no concept or understanding of thermal dynamics and the RH goes on to explain how they original sensor has more thermal mass then the cylinder head and cannot react as rapidly as the cylinder head to changes in temp so it ends up running hotter then it should.

Take a look at DB Dawgs. http://www.dirtwerkz.com/Pages/products/exhaust/dB_Dawg.html They are geared towards dirtbikes but noise is noise.

I'm sorry, not everything I said was specifically to you. I was addressing some things you said and got into some side notes as well. Sorry. I do think that if you think everything on your Guzzi is that way for a good reason you will be wrong every now and then. Adding fuel at very high temps should not hurt mileage much if any. Why Guzzi chose to take fuel away I am not sure, but if I were to guess I'd say it was for emissions reasons, not because it worked better.

If you feel your bike runs better with less accurate ETS readings, I have no problem with that. I will point out that "the way it was designed" was to meet EPA standards and using a completely different formula of gasoline then most if not all of us have today. Things change. New gasoline that burns leaner/cleaner. The whole goo concept was to fix an issue that many of us had, poor fuel mileage. My wifes bike now gets upwards of 40-45 mpg. Not stellar but better then it was. If your bike gets good mileage already or you don't care about mileage then keep the gap, or better yet add a heat sink to your ETS. But please don't try to tell me that adding a heat sink to your ETS or running a gap between the ETS and the head increases accuracy. Your bike may run better with a low ETS reading but that is not the same as more accurate. For what it's worth, I like RHs idea of putting a variable resistor on the ETS signal. It is crude but cheap, and will give the user the ability to adjust the overall mixture on the fly. It is no substitute for a PC3 or TuneBoy, but it could be used as a cheaper less effective alternative or even in addition to a proper map to allow you to tune on the fly and adjust for poor fuel quality or what ever. As far as an advantage in not reading the "high temp spikes", that may be. But my wifes V11 has no issues with them. It would make more sense if the engineers had set it up to add MORE fuel when the temp got over a certain temp and not less, but I would submit that not everything they did when designing spec'ing and building these bikes made sense, was for the best , or was done for a good reason.