Ducati.ms - The Ultimate Ducati Forum banner
  • Hey Everyone! Enter your bike HERE to be a part of this months Bike of the Month Challenge!
1 - 14 of 14 Posts

·
Registered
Joined
·
34 Posts
Discussion Starter · #1 ·
Hi all,

Discovered weird problem when out on a ride this past weekend.

Rode for about an hour, then pulled over to activate a new route in my GPS. Shut the bike off while fiddling with the GPS.

When I attempted to restart the bike, depressing the starter button did nothing. Lights came on, indicator and dash lights came on, I heard the fuel pump kick in, etc., but the satrter did nothing.

I decided to try bump-starting, then things got even more strange. My bump start attempt failed, but after I turned over the engine in gear as a result of the bump-start attempt, the bike started just fine!

I rode home, then reproduced these conditions/results in the driveway. That is, the starter seems not to "kick in" regardless of whether or not bike is in neutral, clutch is disengaged, etc., unless I emulate an engine-turn-over with bike in gear, then it will start right up (both in gear with clutch pulled in and in neutral).

I know most bikes have a neutral sensor or saftery-switch type of thing - perhaps mine is starting to malfunction? My experience is with Japanese bikes - do Ducs have such mechanisms/switches? Can I bypass it easily for testing, etc.

My bike is a '99 ST4, so no microswitch on the clutch lever itself - on which side of the engine should I look for a switch, etc, that I can troubleshoot, replace, etc.

Any help appreciated. I've had the bike about two/three months and still haven't gotten a shop manual yet....

And yes, I suppose I will disconnect the epectric vest hookup and GPS power lead before I diagnose and/or post further on the subject... :)

Wayne Beaver
99 ST4
99 SV Trackdog
90 XR200 Dirtkicker
 

·
Registered
Joined
·
3,999 Posts
No safety switches on the 1998 and 1999 ST machines. These had the auto-retracting side stands that was "the safety" at that time.

Almost sounds like there's a dead spot in your starter. When it did not start, did it make a big CLICK when you pressed the starter button? If it did, it might be the starter. If it did not CLICK, then you might want to check the small connector on the rear of the stater solenoid. This small conn. sometimes works itself loose. Many people in here tie-wrap them in place if they find them loose. The solenoid is the blob that's near the battery, and it's between the batt. and the starter (if you follow the thick + wire from the batt.).

It's function is to take a small signal, from your starter button (like about 1 amp), and when it closes (CLICKS), it can send 200 + amps to the starter motor.
 

·
Registered
Joined
·
34 Posts
Discussion Starter · #3 ·
Yup, starter solenoid and related connections are on list to check, as well.

FWIW, there is no clicking noise when starter button is depressed - jus nothing at all.

Also (not sure this is tremendously important, but...) this bike does not have the self-retractable sidestand. I'm guessing it may have been replaced by previous owners, etc. The sidestand is really short, and bike leans over really far on sidestand (rear ride height adjster is set to lowest/shortest setting) - in fact, I really don't every use the sidestand for that reason.

Wayne Beaver
99 ST4
99 SV Trackdog
90 XR200 Dirtkicker
 

·
Premium Member
Joined
·
5,703 Posts
I think it's pretty well documented these bike have wiring that is too small for the load created by the starter circuit. PowerLet sells a kit that replaces all the wiring from the engine ground to the hot lead on the starter. Pretty inexpensive, and it seems to work. On my bike, when it was hot and if it was on a compression stroke when I tried to start it, it would do as you describe. I installed that kit. No problems since. I also put it on a Battery Tender after each ride during the colder months and once or twice a month just for maintenance in the summer. Just a thought. I guess the best advice is to check your connections for tightness. I’d recommend you go a step further and do a remove, clean, and reinstall of all the starter related connections using a corrosion preventive compound or some sort of dielectric grease. If you don't have a battery charger, it would be a good idea to pick one up (like a battery tender) and use it occasionally for maintenance.

Link to the PowerLet kit. http://www.powerletproducts.com/products/ducati_starter_rewire.php

One more thing. You definitely can't bump start a fuel injected vehicle with a dead battery, but I am also pretty sure you can't bump start one period. Doesn't the computer have to know it's getting the "start up" command by you pushing the button? It needs know when to open the injectors to provide fuel. Maybe if you bumped it while pushing the starter button, you would be able to do it???
 

·
Still needs a life.
Joined
·
12,619 Posts
As an aside....

SS904 said:
You definitely can't bump start a fuel injected vehicle with a dead battery, but I am also pretty sure you can't bump start one period.

I have helped bump start an ST2 and an ST4s. I don't think the batteries of either bike were completely dead, just low.

A battery tender can be plugged in to the accessory outlet through an adapter available through Powerlets or Beemer dealers. I always keep my bike hooked up to the Battery Tender when it is in my garage.
 

Attachments

·
Premium Member
Joined
·
5,703 Posts
Bill_Anderson said:
I have helped bump start an ST2 and an ST4s. I don't think the batteries of either bike were completely dead, just low.
Interesting. The input to the ECU must come from the crank sensor then... It has to get come kind of signal to know when to open the injectors and trigger the spark.
 

·
Registered
Joined
·
34 Posts
Discussion Starter · #7 ·
Quick update.

It appears that the small connector on the rear of the stater solenoid had worked itself loose. I brushed up against it and it fell off entirely! Then I noticed that there is no locking tab on the connector whatsoever!

Anyway, I seemed to be able to get predictable results from connecting and disconnecting the connector, and I will assume that my previously-deemed-predicatable results related to bump-start attempts were probably coincidental and attributable to shaking the precariously connected connector into positions of contact.

So the plan is to reassemble with dielectric grease, zip-tie the connector in place as recommended above in this thread, then see whether or not the problem reoccurs within reasonable time (as I wouldn't entirely rule out that the the wires near the connector could also be broken from vibration and/or a high degree of bend in their routing wuite close to the connection point).

The powerlet-made rewiring option sounds like a good upgrade (especially if the connectors are higher quality, etc., and of course, good battery and charging maintenance are never bad recommendations (though the battery is absolutely fine in this case and perfectly capable of turning the starter - so long as the start switch *is_connected* to the starter solenoid, of course).

Wayne Beaver
99 ST4
99 SV Trackdog
90 XR200 Dirtkicker
 

·
Registered
Joined
·
887 Posts
SS904 said:
I think it's pretty well documented these bike have wiring that is too small for the load created by the starter circuit.

That's not documented anywhere. Actually, when I calculated the voltage drop based upon the length and guage of the wires in the starter circuit and the current draw of the starter motor, I found the gauge of the wires was more than adequate. Sluggish cranking generally appears when resistance builds due to oxidation inside the crimped lug ferrule. The diameter of the wires is certainly not the problem. My 2002 ST4s has been cranking fine with the OEM cables. I recommend treating them with penetrating dielectric grease while they are still new.

One more thing. You definitely can't bump start a fuel injected vehicle with a dead battery, but I am also pretty sure you can't bump start one period. Doesn't the computer have to know it's getting the "start up" command by you pushing the button? It needs know when to open the injectors to provide fuel. Maybe if you bumped it while pushing the starter button, you would be able to do it???
The newer models with the digital instrument cluster may or may not differ in this regard but all of the older fuel injected models can definitely be bump started. The battery can be discharged enough that it doesn't have enough amperage to crank the engine but still have plenty of voltage to run the ECU.
 

·
Registered
Joined
·
49 Posts
wbeaver said:
Quick update.

It appears that the small connector on the rear of the stater solenoid had worked itself loose. I brushed up against it and it fell off entirely! Then I noticed that there is no locking tab on the connector whatsoever!

Anyway, I seemed to be able to get predictable results from connecting and disconnecting the connector, and I will assume that my previously-deemed-predicatable results related to bump-start attempts were probably coincidental and attributable to shaking the precariously connected connector into positions of contact.

So the plan is to reassemble with dielectric grease, zip-tie the connector in place as recommended above in this thread, then see whether or not the problem reoccurs within reasonable time (as I wouldn't entirely rule out that the the wires near the connector could also be broken from vibration and/or a high degree of bend in their routing wuite close to the connection point).

The powerlet-made rewiring option sounds like a good upgrade (especially if the connectors are higher quality, etc., and of course, good battery and charging maintenance are never bad recommendations (though the battery is absolutely fine in this case and perfectly capable of turning the starter - so long as the start switch *is_connected* to the starter solenoid, of course).

Wayne Beaver
99 ST4
99 SV Trackdog
90 XR200 Dirtkicker
Hi Wayne,
the starter solenoid plug is a common issue, I've seen it discussed in the Yahoo ST group, that plug is the one and only reliability problem that my 2002 ST2 has ever had. I've ridden the bike 25,000 miles with nothing else ever going wrong! I was having lunch one day at a local BBQ joint and hopped back on the ST for the ride home... push the starter button... nothing! I hee-hawed and hummed around through the fairing opening and didn't expect much, but the bike started up. I came home and pulled the fairing off, and after some head scratching and poking around, I found exactly the same problem as you did. I even did the exact same fix, zero trouble since.
Some people say Ducatis are unreliable, those people are wrong, and they don't deserve a Ducati.
Leo Smith
now powered by ST4s and ST2! Yippie! (and a ZX10R for sale)
 

·
Premium Member
Joined
·
5,703 Posts
Mike said:
That's not documented anywhere. Actually, when I calculated the voltage drop based upon the length and guage of the wires in the starter circuit and the current draw of the starter motor, I found the gauge of the wires was more than adequate. Sluggish cranking generally appears when resistance builds due to oxidation inside the crimped lug ferrule. The diameter of the wires is certainly not the problem.
To the OP. Good deal on it being a simple fix!

Well, Mike... I did say "I think" and "pretty sure" as in I understand I'm not the expert, but has been my experience... I assume when you calculated the drop across those cables and measured the current draw on the circuit with the motor pulling, you also considered the many variables. Differing resistance in the cables supplied by the factory due to manufacturing inconsistencies like cable length and quality of the solder joints, for example? This, of course, would have a direct effect on the level of voltage dropped on the cables from bike to bike and ultimately how much was left over to make the starter motor spin. I assume you considered the fact that engine age (compression), even temperature, as well as starter motor age could directly impact the current draw with that starter under load? For example, a bike during a hot start would likely draw a bit more current as the starter tried to push a piston through its compression stroke, than a cold bike that has been sitting over night... No? A combination of that hot start with a poor set of cables could be just enough to cause the problem.

It is highly likely replacing the cables with higher capacity, better quality items, as offered by Powerlet, will help to eliminate sluggish starting. Dirty, loose, corroded connections are obviously the biggest contributor. You may have read in my original reply that I suggested addressing that very thing as a remedy. I would be willing to bet, in many cases, the sluggish starting problems corrected by installation of these cables is due to the better connections and consistently good manufacturing process more than the simple fact that they are of a higher capacity (and probably lower resistance) cable materiel. I would be willing to bet, and since you mentioned voltage drop, that you would find a lower measured resistance on the Powerlet cables compared to the factory pieces. You would also likely see a more consistent resistance reading across a number of samples of those cable when compared to a similar sampling of the factory cables.

The fact that Powerlet offers this kit for the ST series, and not any other model that I could see, indicates a possible problem does exist. They also offer a kit to beef up the power outlet wiring for the ST series because it is said to be inadequate as well. Dare I say documented? I have had an issue with this myself, and have read of others having the problem too. Good enough for me to consider it at least “known”, if not well documented…

Don’t know about the bump starting deal… I assume as long as there is enough power in the battery to power the fuel pump, generate a spark, and power the ECU, it should work. My doubt comes from not knowing how the ECU knows it’s trying to start the engine. What triggers it to fire the injectors at start up?
 

·
Registered
Joined
·
647 Posts
SS904 said:
...Don’t know about the bump starting deal… I assume as long as there is enough power in the battery to power the fuel pump, generate a spark, and power the ECU, it should work. My doubt comes from not knowing how the ECU knows it’s trying to start the engine. What triggers it to fire the injectors at start up?
The ECU works out when to fire the injectors and when to fire the plugs from crankshaft position sensor.
I completely agree with your reasoning on the starter wires.
 

·
Registered
Joined
·
887 Posts
SS904 said:
The fact that Powerlet offers this kit for the ST series, and not any other model that I could see, indicates a possible problem does exist. They also offer a kit to beef up the power outlet wiring for the ST series because it is said to be inadequate as well. Dare I say documented?

It was not my intention to get into a pissing match or to say battery cables do not oxidize and age. My point is the gage of the OEM cables are not a problem. The OEM cables are likely a metric size but the size is not marked on either of my ST's. Looking at the end of the OEM cable it is difficult to tell if they are smaller (or not) than the AWG 6 cables that are available in the aftermarket. The aftermarket cables have nearly the same diameter of copper as the OEM cables and this size is perfectly adequate for the task at hand with margin to spare. When I did the calculations I assumed AWG 8 which is actually considerably smaller in diameter than the actual OEM cables.

The reason the gauge is not a problem is the very short length of the cables. My ST4s has only 3 feet of starter cable total (including the ground). Even if the OEM cable was only 8 AWG (less than 3.8 mm in dia.) that would translate to only .0018 ohms resistance for all the cable runs. Because the OEM cable is closer to AWG 6 gage the actual resistance is closer to the .0012 that the aftermarket cables have. So we are talking a difference of perhaps .0001-.0004 ohms at best due to the (presumably) smaller wire gage. This amount of resistance will be dwarfed by the resistance between the lug crimps and cable and between the lugs and bolts (not to mention the resistance in the relay contacts).

As to the quality of the OEM cables, the ones on both of my ST's are made by Leoni to international standards and appear to be well tinned (or plated with another type of bright metal). I protected both of my ST's starter cables when the bikes were new and neither one has had any trouble cranking even at temperatures below freezing or in the desert over 100 degrees F. One of them has 37,000 miles on it and the OEM battery was finally replaced after 5 years, not due to slow cranking but simply as preventative maintainance so I know the cables are working fine.

Please don't misunderstand me again, I am not claiming the OEM cables are the highest possible quality. In fact, there have been a number of ST owners who have corrected slow cranking by replacing oxidized OEM cables. My point is simply that there is not a problem with the GAGE of the stock cables.

Regarding the wiring to the power outlet under the seat being inadequate I guess that depends upon your perspective. From the factory it is protected with a 3 amp fuse (on the early models) and the wiring is more than adequate for hooking up a battery tender or any other use consistent with the 3 amp rating of that circuit. If you want to run heated clothing you will need to upgrade the circuit above it's intended 3 amp limit. Actually, I've heard of people drawing over 10 amps on the OEM wiring just by replacing the 3 amp fuse with a 15 amp fuse without issue. But I would strongly advise against using that wiring for more than it's fused limit just for safety reasons. So, yes, the stock wiring IS inadequate for running high draw appliances and that IS well documented (in your owners manual of all places).
 

·
Registered
Joined
·
49 Posts
Well said Mike,
I do have one question though, where the heck do you find penetrating dielectric grease?
Leo Smith
 

·
Registered
Joined
·
887 Posts
DucatiST said:
Well said Mike,
I do have one question though, where the heck do you find penetrating dielectric grease?
Leo Smith
I found it at my locally owned mom-n-pop hardware store (best store in a 50 mile radius if you ask me). I've looked in the big chain stores (Ace, Sebo's, Eagle, Tru-Value, etc.) and have NEVER found it. It's CRC product #02083 in an aerosol can.
 
1 - 14 of 14 Posts
Top