Page 14 of 15 FirstFirst ... 412131415 LastLast
Results 196 to 210 of 216

Thread: Summer running - 2000 Ducati ST2

  1. #196
    Join Date
    28th January 2015 - 16:17
    Bike
    2000 Ducati ST2
    Location
    Lower Hutt
    Posts
    1,239
    Ouch. Well I guess I just got told, big time.

    Bob, the rear temperature sensor has already been replaced... they both have. Anyway if you have a temperature specification chart, believe me, I am very interested... I simply couldn't find anything online beyond a resistance at room temperature and of course Ducati are unlikely to hand out diagnostic information for free.

    As to your criticisms, well... yeah. Fair enough. Point by point...

    Loads of my writing is wild conjecture. If I'm doing that, I try to say so, that I'm guessing, that I'm not certain. I go there because I'm interested. Almost all of the time, what I find out is that existing practice is like it is for very good reasons... but until I go through those reasons, I don't know them.

    This is a hobby. I'm not in the trade (thank fuck) and I'm free to be as eccentric an amateur as I want to be. I don't have to operate under the brutal paradigm of get it fixed right now for the lowest price possible, and you're right, if I did I'd pick up some common sense in one hell of a hurry.

    Asking for help: Yep. The usual story with these forums is: want to ride, bike's down, need help. Again, fair enough, that's the usual format. I'm interested in, why is the bike down? What's gone wrong? Do we need to change the bike, so this doesn't happen again? It's just a different point of view.

    Viscosity of petrol: quite frankly I would be amazed if petrol had a truly constant viscosity with temperature. The same for density, it'll expand and contract like an oil does. The question is, would this be enough of an effect to be significant over the operating temperature range of fuel in lines or fuel in a tank? Probably not (your direct experience is being listened to btw) but (BUT) I know that the problem I am chasing gets worse if the bike warms up. It didn't used to do this. The fuel lines haven't been shifted in location between running OK and having the issue. So yes, you are right, this is off-the-mark conjecture, I'm chasing a ghost and hot fuel lines might be an issue to a perfectionist but almost certainly aren't the issue here. Since we're on the topic, have a look at this paper: https://nvlpubs.nist.gov/nistpubs/nb...cpaperT125.pdf it's seriously vintage but it's still about gasoline.

    Changing out the fuel pressure regulator: it's 20 years old, I know that it's not making 3 bar any more, it's given good service but we're now well past the expected lifetime of the bike. Is it really a surprise that it might be on the way out? And wasn't the entire post based around the fact that I took a diagnostic measurement, tried to understand what it meant, and made a decision based on that, instead of a guess and shoot game where I replaced parts until the problem went away?

    Finally... yeah I really can't argue with you concerning 'misguided adventures', quite honestly that is true. I really need to get myself out of this situation of old bikes constantly breaking down and three to six months of trying to work out what has gone wrong this time.

  2. #197
    Join Date
    5th January 2007 - 14:58
    Bike
    motocompo
    Location
    Buttfuck nowhere
    Posts
    5,146
    Did you pinch off the return line with pliers when you did the fuel pressure test to see if the pump was capable of a momentary spike reading of 80psi plus?
    The regulator can only regulate downwards from pump pressure, so if the pump is on it's way out, replacing the regulator wont bring the pressure up.
    I would have replaced over 100 pumps to one regulator on average. It's not the regulator that's "making" 3 bar, it's the pump for a start.
    The main reason regulators were replaced is because the diaphragm split & the engine started sipping fuel through the vacuum hose, causing a rich scenario & a rough idle.
    I assume you have run it with the vac tube off to see if it drips fuel out of there?
    If it's a mixture issue you can't get on top of any other way, you can install a variable resistor in the temp sensor loom & dial it progressively over a few runs to obtain the best running.
    Once you are happy with how it runs measure the resistance you have it dialed to, & buy the corresponding resistor from Jaycar & install it in the circuit.
    This was a standard way to get early L Jet 6 cyl Jaguar's to run properly.
    I've seen plenty of thirty plus year old pressure regulators, with near 400,000km on them operate faultlessly, failure is more the exception than the rule.
    I see your paper on the viscosity of gasoline, which I was fairly sure would be thrown at me for mentioning that viscosity was constant.
    But the fact is, that you don't go to a petrol station on a cold day & It takes longer to fill the car.
    It comes back to that chasing of non issues I mentioned earlier, red herrings if you will, so regardless of some scientific paper that looks to be 100 years old, let's pretend for the purpose of an expedient diagnosis of the problem in hand, that the fuel is a relative constant.
    I'm sure I could also find papers to prove that their is little in common with petrol produced in 1919 & petrol produced today, and I can assure you that you will not find a fix of any type in that paper to remedy the fault with your motorcycle, apart from to prove me wrong on a mute point.
    Re the temp sensor, work on 360 ohms at 85 degrees or thereabouts, it's not an exact figure you are after, just ballpark 350-400 ohms.
    I hope that helps. I'm mainly posting out of the frustration of watching you chasing your tail & wasting money on something relatively simple.

  3. #198
    Join Date
    28th January 2015 - 16:17
    Bike
    2000 Ducati ST2
    Location
    Lower Hutt
    Posts
    1,239
    Quote Originally Posted by sidecar bob View Post
    Did you pinch off the return line with pliers when you did the fuel pressure test to see if the pump was capable of a spike reading of 80psi plus?
    The regulator can only regulate downwards from pump pressure, so if the pump is on it's way out, replacing the regulator wont bring the pressure up.
    I would have replaced over 100 pumps to one regulator on average.
    From memory the temp sensor should be around 360 ohms at 85 degrees, or thereabouts.
    If it's a mixture issue you can't get on top of any other way, you can install a variable resistor in the temp sensor loom & dial it progressively over a few runs to obtain the best running.
    Once you are happy with how it runs measure the resistance you have it dialed to, & buy the corresponding resistor from Jaycar & install it in the circuit.
    This was a standard way to get early injected 6 cyl Jaguar's to run properly.
    I've seen plenty of thirty plus year old pressure regulators, with near 400,000km on them operate faultlessly, failure is more the exception than the rule.
    I see your paper on the viscosity of gasoline, which I was sure would be thrown at me for mentioning that viscosity was constant.
    But the fact is, that you don't go to a petrol station on a cold day & I takes longer to fill the car.
    It comes back to that chasing of non issues I mentioned earlier, red herrings if you will, so regardless of some scientific paper that looks to be 100 years old, let's pretend for the purpose of an expedient diagnosis of the problem in hand, that the fuel is a relative constant.
    OK, that's direct experience talking. Right, pinch test and check the fuel pump it is, particularly with that ratio of pump to regulator failure. Thanks for that, that's very useful.

    Everything I've read about these bikes says that the stock map is set lean, for compliance issues. It's why I'm being fussy about this stuff; I get the impression that as stock it's right on the edge of reliability and rideability, and it wouldn't take much going wrong in terms of leaning the mixture out further to cause problems.

  4. #199
    Join Date
    5th January 2007 - 14:58
    Bike
    motocompo
    Location
    Buttfuck nowhere
    Posts
    5,146
    Quote Originally Posted by OddDuck View Post
    OK, that's direct experience talking. Right, pinch test and check the fuel pump it is, particularly with that ratio of pump to regulator failure. Thanks for that, that's very useful.

    Everything I've read about these bikes says that the stock map is set lean, for compliance issues. It's why I'm being fussy about this stuff; I get the impression that as stock it's right on the edge of reliability and rideability, and it wouldn't take much going wrong in terms of leaning the mixture out further to cause problems.
    Nearly everything is on the edge regards fuel mixture, the factory fuel maps are usually great, just low.
    A good way of overcoming an overall low map is an adjustable fuel pressure regulator.
    Seeing as injection volume is a pressure over time calculation, if you are chasing a lean situation, the first thing you need to work out, is the fuel pressure too low, or is the injector open time too short.
    It takes a couple of minutes to work out if its low pressure, and if the pressure is ok, then it must come back to insufficent injector dwell, or time spent open, there is no third option. Test for the reverse scenario in a rich situation.
    You have now got a foot firmly in one camp or the other & diagnosis and repair can go down an orderly path from that point.
    It's fairly obvious what to do if the pump is unable to create sufficient pressure created by the restriction of the regulator.
    If the pressure is sufficient, then it's got to be injector dwell. That's when you check sensor outputs against either book specs, or a vehicle of the same type that runs well.
    During my time as a garage owner, occasionally I would test & record sensor outputs of vehicles that were only in for servicing that ran particularly well, & record them in a very thick folder called "BMW Technical data Vol 1" as apart from the fact that I was doing that prior to the diagnostic machines existing & the internet being a thing, google does not replace personal experience & time on the job, as it's full of enthusiastic amateurs that think owning one BMW E30 for six months, having an opinion & an internet connection makes them a world authority on the topic of everything related to them.
    Anyway, back to the fuel pressure regulator, it's another option to installing a resistor in the temp circuit & results are comparable, it just depends on what route you want to go. Obviously the ajustable regulator increases fuel pressure & the resistor increases injector open time. Use one or the other, but never both at once.
    Personally, for a racing application, I'd probably go pressure regulator & go the resistor route for a road vehicle. I don't really know why I think that way, it's just instinctive. Actually, thinking about that one, it's because a regulator can be quickly adjusted to compensate for a change in racing conditions, which is difficult with the resistor system & adjustment is not likely to be required on a street vehicle. It would also seem normal to have a permanently installed fuel pressure gauge on a race machine.
    Packaging of the resistor is near invisible compared to an adjustable regulator & drongos that think more is better are more tempted to mess with an adjustable regulator willy nilly. Using a resistor is also the most cost effective option, even when you buy an adjustable reostat first to dial it in.
    The last sidecar I raced went from 167HP to 214 with nothing more than a pressure regulator and some dyno runs, running stock ECU.
    We didn't measure fuel economy, as that wasn't what we were chasing, although the lambda on the dyno said the mixture was right in the window.
    I also installed adjustable pressure regulators to a number of Cosworth Sierra's with standard ECU & the results were astonishing, and probably for higher horsepower expectations the regulator may be a better option.
    It's very difficult to find a dyno guy that will help you with that kind of system on a bike, as most are in the business of selling you a Power Commander or such & look down their nose at you as some kind of boy from the bush, when you're using cost effective solutions that are at least the equivalent of their product, also possibly because while they can programme a fuel map, they don't understand your methods & write you off as an idiot.
    That's why I suggested a bit of real world riding over a few days to set it up.
    I'd hate to be the guy that sent you down a rabbit hole, but if it were my bike I'd be releasing the trapped ponies one way or the other.

  5. #200
    Join Date
    8th July 2018 - 07:46
    Bike
    Ducati ST2 2003
    Location
    whakatane
    Posts
    22
    Well thats quite an interesting conversation.

    I have cored mufflers on my ST2 so it should be running lean, but looking at plugs and fuel economy (measured before and after the cored pipes went on) nothing changed at all (other than a better sound).
    Sure it would benefit from some opening up and at only 84hp could probably use some more HP but i also like that i can get over 400km from a tank when touring so will stick with what i have, reliability is my main concern.

    As far as the spare parts goes, I have just brought a new shindagen regulator and electrosport stator, not because there is anything wrong with mine, but just in the interests of reliablity, on a touring machine its often a long long way home even in NZ and i tend to do a lot of obscure back roads on my own with zero cell cover, so maybe i have spent money i didn't have to, but maybe i havent, guess i will never know (unless the new regulator dies.....)

    Keep the conversation coming, I am learning a lot just reading

    I measure my KM and Litres EVERY time i fill up and rely on that number to tell me if anything changes on the bike, it seems pretty accurate because fuel economy on the ST2 doesn't seem to change regardless if it is hours of gravel, a pootle with the wife on the back or high speed higway, always round 19.2km/l

    Regards
    Noel

  6. #201
    Join Date
    3rd March 2008 - 11:55
    Bike
    0094473185
    Location
    Riding the evil flatlands
    Posts
    2,156
    Quote Originally Posted by OddDuck View Post
    the rear temperature sensor has already been replaced... they both have. Anyway if you have a temperature specification chart, believe me, I am very interested... I simply couldn't find anything online beyond a resistance at room temperature and of course Ducati are unlikely to hand out diagnostic information for free.
    I've had a play with the temp sensors on mine, figured a quick and dirty way to work them out was stick a variable resistor on the temp gauge input and graph the results. Short answer is that there are a heap of them available that have very similar characteristics, and the difference is likely to effect the running of the bike bugger all.

    Quote Originally Posted by sidecar bob View Post
    The main reason regulators were replaced is because the diaphragm split & the engine started sipping fuel through the vacuum hose, causing a rich scenario & a rough idle.
    I assume you have run it with the vac tube off to see if it drips fuel out of there?
    Thanks for that, will have to have a look at mine and see if that's the cause of it's apparent running rich at idle and generally being an unrideable pig, currently it's a naked garage queen because I've run out of ideas and can't be arsed.
    Riding cheap crappy old bikes badly since 1987

    Tagorama maps: Transalpers map first 100 tags..................Map of tags 101-200......................Latest map, tag # 201-->

  7. #202
    Join Date
    28th January 2015 - 16:17
    Bike
    2000 Ducati ST2
    Location
    Lower Hutt
    Posts
    1,239
    OK, I've finally got around to running the pinch test as suggested by Sidecar Bob, letting the fuel pump go to maximum pressure. Also, the pressure regulator doesn't appear to have a vacuum hose on this bike - the spigot visible on the underside of the fuel tank has always been bare and there's no provision on the manifolds for permanent connection to a vacuum hose, although they carry vacuum test ports accessible from the flanks.

    According to the manual the pump is supposed to pressure release at 5 bar / 75ish psi. This test shot straight past that and made what looks like 100 psi + (at this point my gauge had topped out).

    From the manual, verbatim:

    The electric pump is volumetric and has rotating lobes, with the motor immersed in the fuel. It is a brush motor energised by permanent magnets. The pump has a non-return valve which prevents emptying of the fuel circuit when the pump is not running. It also has an over-pressure valve which short-circuits the intake when the pressure exceeds 5 Bar. This prevents overheating of the electric motor.

    At this point I need the voice of experience, anyone have a comment about this result please?

    Neels, what symptoms have you seen and what tests have you made so far?

  8. #203
    Join Date
    24th September 2004 - 06:46
    Bike
    '76 CB550 Super Sport
    Location
    On the road to nowhere...
    Posts
    6,988
    Quote Originally Posted by OddDuck View Post
    OK, I've finally got around to running the pinch test as suggested by Sidecar Bob, letting the fuel pump go to maximum pressure.

    According to the manual the pump is supposed to pressure release at 5 bar / 75ish psi. This test shot straight past that and made what looks like 100 psi + (at this point my gauge had topped out).

    From the manual, verbatim:

    The electric pump is volumetric and has rotating lobes, with the motor immersed in the fuel. It is a brush motor energised by permanent magnets. The pump has a non-return valve which prevents emptying of the fuel circuit when the pump is not running. It also has an over-pressure valve which short-circuits the intake when the pressure exceeds 5 Bar. This prevents overheating of the electric motor.

    At this point I need the voice of experience, anyone have a comment about this result please?

    Neels, what symptoms have you seen and what tests have you made so far?
    Fuel pump is obviously out of step and needs adjusting if possible or replacing. I'm gathering the later.

  9. #204
    Join Date
    5th January 2007 - 14:58
    Bike
    motocompo
    Location
    Buttfuck nowhere
    Posts
    5,146
    Your pump is sweet, it could go to 100psi, but the fact that it far exceeds what the regulator pulls it back to is all that matters in this scenario.
    Fit the regulator when it turns up & go from there.
    Not completely unusual for the regulator vac tube to be blanked off in some applications.

  10. #205
    Join Date
    28th January 2015 - 16:17
    Bike
    2000 Ducati ST2
    Location
    Lower Hutt
    Posts
    1,239
    New fuel pressure regulator arrived and fitted. Went for ride and significant improvement although not quite 100%... might have something useful for other ST owners though. While changing out rear brake pads (another story) I had the RH muffler off and finally noticed that the swivel joint at the cross was not seating properly.

    The swivel's a cylinder-within-a-cylinder several times over labyrinth seal. There's no gasket: it relies on a long path length between close fitting surfaces to function as a gas seal. If it's only pushed halfway home (as mine was) then that'll affect the way it works. I've never cleaned these joints before and they were gunked up with soot. The spring was holding everything together but the joints weren't seating properly.

    I cleaned everything up, both sides, with white spirits, rag and paintbrush (the bristles will reach to the bottom of the labyrinth), reassembled and rode. Big improvement in how the bike ran.

    After 20 - 30 minutes of riding there's still a very faint remainder of the rough running problem. It's nowhere near as bad as it was but something's still there. I'm inclining towards old ignition coils and HT insulation breakdown (20 y.o. bike, 52,000 km's), but don't know how to test for this. The coil winding resistances test fine btw. Does anyone have any experience checking for HT leaks in these, please?

  11. #206
    Join Date
    24th September 2004 - 06:46
    Bike
    '76 CB550 Super Sport
    Location
    On the road to nowhere...
    Posts
    6,988
    My goodness only 52,000kms. My'76 CB550 has done 161,000kms on original coils/leads and I've replaced 2 plug caps and it's on points ignition.

  12. #207
    Join Date
    3rd February 2004 - 08:11
    Bike
    1982 Suzuki GS1100GK, 2008 KLR650
    Location
    Wallaceville, Upper hutt
    Posts
    4,420
    Quote Originally Posted by OddDuck View Post

    After 20 - 30 minutes of riding there's still a very faint remainder of the rough running problem. It's nowhere near as bad as it was but something's still there. I'm inclining towards old ignition coils and HT insulation breakdown (20 y.o. bike, 52,000 km's), but don't know how to test for this. The coil winding resistances test fine btw. Does anyone have any experience checking for HT leaks in these, please?
    Run the engine in a really dark shed (door open of course) you might see something, But simple substitution might be easier, depending on the price of Ducati coils
    it's not a bad thing till you throw a KLR into the mix.
    those cheap ass bitches can do anything with ductape.
    (PostalDave on ADVrider)

  13. #208
    Join Date
    3rd March 2008 - 11:55
    Bike
    0094473185
    Location
    Riding the evil flatlands
    Posts
    2,156
    Quote Originally Posted by OddDuck View Post
    Neels, what symptoms have you seen and what tests have you made so far?
    Don't know, it's cold out in the garage at the moment.

    I'll have to dig out the pressure gauge I've got sitting in a drawer somewhere, and see what pressure there is on the fuel circuit, overpressure to the injectors could explain why it seems to be running very rich at idle.
    Riding cheap crappy old bikes badly since 1987

    Tagorama maps: Transalpers map first 100 tags..................Map of tags 101-200......................Latest map, tag # 201-->

  14. #209
    Join Date
    8th July 2018 - 07:46
    Bike
    Ducati ST2 2003
    Location
    whakatane
    Posts
    22
    Has anyone ever seen an adjustable fue pressure regulator for the ST2, raising the fuel pressure a tad could make a difference to performance with open pipes, just a thought.

  15. #210
    Join Date
    5th January 2007 - 14:58
    Bike
    motocompo
    Location
    Buttfuck nowhere
    Posts
    5,146
    Heres one option you could explore.
    http://www.mattlewisracing.co.uk/pro...t_lewis_racing
    The part number is WFR505, you can search up a different supplier maybe.
    Happy to assist you with set up advice by PM.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •