Skeeve Posted April 1, 2009 Posted April 1, 2009 Nonsense! It absolutely causes the temperature to be hotter. Now you are talking! You are admitting that the goo causes the temperature to deviate from the engineers intended, right? Or are you saying the engineers intended to add goo? Dave, pay attention! The goo doesn't have any caloric of its own! Get with the program; the goo only changes the speed of the sensor registering the change in engine temp (frequency), not the amount of that change (amplitude.)
Skeeve Posted April 1, 2009 Posted April 1, 2009 Why did Guzzi use an adapter? Why not just screw it into the cylinder head? I think I know this: they wanted the stand off so that the sensor wasn't perpetually heat-soaked by the surrounding finning. Kind of a "can't see the forest for the trees" issue... Of course, if they'd just plugged straight into the head, the conduction path would be thru the sensor body and we wouldn't need to worry about adding goop, heatsinks or any of the rest of this... Maybe they were concerned about melting the connecting wires? Irrelevant to our concerns, anyway; we've got to work with what we have!
Dan M Posted April 1, 2009 Posted April 1, 2009 Put it this way: If you first add goo without getting problems, then replace your exhaust and end up with a too lean bike, would that still make you say the goo is the problem? Or would this make you say the exhaust caused the engine ro tun leaner than engineers planned? Is the order important here? Ther are a few ways to look at this. When my bike was completely stock with very low miles it had a lean surge about 4000 rpm. When I changed the mufflers with no other mods the surge was still there and maybe a bit worse. Next I changed the crossover and added a PC3. The surge was eliminated. Over the next two seasons I added pistons and other mods but with a little map tweaking my bike always ran very well. The only time I ever had any trouble was on very hot (90F+) days and I'd get a lean pop at times on throttle opening at low rpm. While doing some off season maintenance I added some copper paste to the cavity in the plastic holder for no other reason other than after reading about it here and it sounded like a valid idea. After that, in any temp above 70F the bike had lean issues. Adding fuel via the PC3 in the problem areas helped but it was never the same as when there was no paste in the holder. So in my case the goo was the last change and it seems, the culprit. I still feel that the engineers were looking to ballpark the temp and didn't want the high temp spikes associated with an air cooled engine factored into the mix. Next step for me anyway is to clean out the paste and see how it runs.
Dan M Posted April 1, 2009 Posted April 1, 2009 Dave, pay attention! The goo doesn't have any caloric of its own! Get with the program; the goo only changes the speed of the sensor registering the change in engine temp (frequency), not the amount of that change (amplitude.) I'm not too sure about this. If there is an air space between the sensor tip and the head it will never see the temp peaks as it does if there is direct contact (via goo) Next time you have a pot on the stove lift it up and place your finger about 5mm away from the bottom of the hot pot. It will feel pretty hot but not as hot as if you actually touch it. No? Since everybody is experimenting do this with goo in one finger and no goo on another, touch the goo to the pot for a minute and see if that finger gets hotter than the one that has an air space.
Skeeve Posted April 1, 2009 Posted April 1, 2009 Next I changed the crossover and added a PC3. ...While doing some off season maintenance I added some copper paste to the cavity in the plastic holder for no other reason other than after reading about it here and it sounded like a valid idea...Next step for me anyway is to clean out the paste and see how it runs. First off: The "add goo" rubric is solely for those experiencing poor mileage issues or doing short-haul commutes in cooler weather, where the excessive "engine cold" fueling prevents the engine from coming up to temp in the brief ride time before shutting off & you wind up getting "mayonnaise" in your engine as a result. Ratchethack rides on Mt. Palomar frequently, which is about the only reason I could foresee someone needing to add goo to their sensor holder here in sunny Lo-Cal So. Cal. [where the money is plastic & the people are too!]: we're not exactly on the list of "cold environments" Guzzi had in mind when they were working up the injection map... Secondly: if you already had the PC3 on your bike, why would you add a variable to the system? The PC3 isn't adaptive; any added variables essentially require a remap [altho' you can get away w/ some minor changes & not end up outside the "acceptable performance envelope." Don't bother removing the goo: get your PC3 remapped w/ all the present variables [make sure the engine is good & hot when they do it] and you should be happy once more... and then don't change anything!
Skeeve Posted April 1, 2009 Posted April 1, 2009 I'm not too sure about this. If there is an air space between the sensor tip and the head it will never see the temp peaks as it does if there is direct contact (via goo)Next time you have a pot on the stove lift it up and place your finger about 5mm away from the bottom of the hot pot. It will feel pretty hot but not as hot as if you actually touch it. No? Since everybody is experimenting do this with goo in one finger and no goo on another, touch the goo to the pot for a minute and see if that finger gets hotter than the one that has an air space. Not a valid experiment. So seriously flawed that I'm not even going to bother pointing out why. Anyway, I believe your point is that Guzzi's intent was for slow sensor response, and we're all committing an error by attempting to defeat this. This is a valid argument, but neglects the problems experienced by several? many? w/ the slow sensor response affecting the fueling to [subjectively] an excessive degree.
Dan M Posted April 1, 2009 Posted April 1, 2009 Secondly: if you already had the PC3 on your bike, why would you add a variable to the system? The PC3 isn't adaptive; any added variables essentially require a remap [altho' you can get away w/ some minor changes & not end up outside the "acceptable performance envelope." Don't bother removing the goo: get your PC3 remapped w/ all the present variables [make sure the engine is good & hot when they do it] and you should be happy once more... and then don't change anything! Here's the thing. I've always subscribed to the fact that the best positive contact should be made when sensing temp. That is how everything that I've ever serviced BG (before guzzi) was designed to operate. I run a shop that specializes in emission repair. Accurate fuel injection is kinda my thing. I thought if I could improve fueling on this stab in the dark system, I'd give it a try. Following that train of thought the goo seemed like the right thing to do. Now after experiencing the trouble I am of the thought that the gap is there for a reason. (as talked about at great length 30ish pages ago) The factory map was likely made with the plastic sensor without goo so that is the way I'm leaning now. Sensing the higher temp spikes with this simple system is unnecessary. As I have said, when an air cooled engine is at an extreme temp you want to add fuel not take it away. Running on a hot day and at slow speeds as when stuck in traffic, the head temp soars. If you are sensing the temp spike and mixture is leaned as a result you are adding to the problem with the increased combustion temps. If the mix stays rich the engine will stay cooler. It would follow that there is an advantage in not reading the high temp spikes. (as the air gap accomplishes) My bike ran really well before. I'm returning to the way it was designed. It was fine before the change. Why would I not go back to the scene of the crime? As far as problems experienced by many, it seems like far more have the part throttle, mid rpm, lean misfire to complain about than those who want better economy. But that's just my opinion. Oh, and the holding your finger to the hot pot thing was a joke. (that's what the whistling emoticon was about) I didn't really expect anybody to try it. I guess we shouldn't try to mix in humor.
dlaing Posted April 2, 2009 Posted April 2, 2009 Maybe not Dave, checking guides is pretty easy on the Guzzi especialy if you have access to a compressor and a compression tester. I can walk you through it if you like. Thanks Dan! Unfortunately I don't have a compressor, just a bicycle pump But I am curious as to what the process is.
dlaing Posted April 2, 2009 Posted April 2, 2009 I mean if you have goo and experience lean issues, why do you presume it is because of the goo? What if the base map was too lean to begin with, but just within margins for not giving much problems? Put it this way: If you first add goo without getting problems, then replace your exhaust and end up with a too lean bike, would that still make you say the goo is the problem? Or would this make you say the exhaust caused the engine ro tun leaner than engineers planned? Is the order important here? I did not use goo, I used a coil of solder to increase the conductivity. I pulled it out and it immediately ran much better. The lean running symptoms were greatly reduced. I am sure the base map has some cells that are "too lean to begin with, just within the margins for not giving much problems" That is why people rave about the PCIII, which mostly enrichens on top of the base map. Both the goo and an aftermarket exhaust make it run leaner than the engineers planned. Running leaner than the engineers planned is not necessarily going to produce symptoms that people will detect. But compounding the leanness from aftermarket mufflers and goo without modifying the fueling is looking for trouble.
dlaing Posted April 2, 2009 Posted April 2, 2009 Dave, pay attention! The goo doesn't have any caloric of its own! Get with the program; the goo only changes the speed of the sensor registering the change in engine temp (frequency), not the amount of that change (amplitude.) The amplitude is increased, too. Ratchet and I have verified this with testing, yada yada yada. Of course if you wrapped the sensor in neoprene foam and duct tap, then that amplitude ain't gonna change much from adding goo, but of course it will be even hotter. And if you added Ratchet's heat sink we get a cooling effect that hopefully balances the adding of goo. In this case, the change in amplitude from adding goo will be even greater. Whether it is hotter than no goo and no heat sink depends on the size of the heat sink and some other factors. But what is a valid point is that benefits in speed increase may out weigh the increase in read temperature, if your bike is running rich enough to begin with or your are prepared to modify the fueling.
dlaing Posted April 2, 2009 Posted April 2, 2009 Maybe they were concerned about melting the connecting wires? Or the plastic part of the sensor. Or keeping the sensor in designed ideal range.
dlaing Posted April 2, 2009 Posted April 2, 2009 Forget what I said in the last few posts. Dan says it much better.
mike wilson Posted April 2, 2009 Posted April 2, 2009 By the time we reach page 42, we should have the answer.
dlaing Posted April 2, 2009 Posted April 2, 2009 By the time we reach page 42, we should have the answer. Someone said if you disconnect the wire to the sensor the engine runs fine. That could be the solution Or buy a Honda Or make your own adapter out aluminum, bakelite,(with cooling fins on the sensor side)(design it so it can be tightened with a spark plug wrench without torquing the bakelite section), add goo, and use TuneBoy to modify the map.
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