Bimota Forum

quikduk · Posted: Fri May 24, 2019 5:03 pm Post subject: DB6 died when riding today

Well crap!

I was going to work this AM and was about 1.5 miles away from my house when the engine just died. I shifted down to neutral, played with the throttle but the engine was effectively "off".

I pulled over, looked at the digital dash and all looked good except my battery voltage indicator looked low. Now I have a fairly new EarthX LiPo battery installed and keep the bike connected to a smart trickle charger when not in use so I doubt its the battery.

I was able to get it restarted and back home and when I pulled it into the garage and shut it off, thats when the questions really came up.

quikduk · Posted: Fri May 24, 2019 5:11 pm Post subject:

I turned the ignition back on and the dash lit up but with the VM first indicating 9.9V, then 12.2 V. This may be caused by the battery needing a load to know it needs to provide adequate power (typ. of LiPo batteries as some require the high beam switch to be on for a minute prior to starting, esp. with Ducatis). It was charging at 12.4V on the dash (which reads low as a meter across the charger contact harness reads around 12.8V-13.2V when running).

Anyway, no go when I pushed the starter button and I could see a load being applied as the headlight dimmed. Additionally, no fuel pump noise and no starter crank. This leads me to the following possibilities:

- blown starter fuse
- blown fuel pump fuse
- bad starter
- bad fuel pump
- bad ECU

Anyone else with this experience? I don't have time to test it now as I had to borrow the wife's 5.0L Mustang (oh darnit!) to get to work today.

I guess I'll start checking the easy things like loose wires, fuses, power to various parts and pieces before getting really into it. I'll report on my progress. At least it happened where I could get back home quickly and it didn't strand me on the highway or at work. Sigh... Rolling Eyes

quikduk · Posted: Fri May 24, 2019 8:13 pm Post subject:

I just had another thought re: the cause. Would a faulty Crankshaft Position Sensor or other sensor cause the issues I am experiencing (no starter or fuel pump sounds)?

brian · Joined: 22 Aug 2011 Posts: 3769 Location: Australia

quikduk · Posted: Sun May 26, 2019 5:49 am Post subject:

Checked resting battery voltage. 13.34

Checked two 25A fuses. OK

Checked power to starter solenoid. OK

Still no crank and no fuel pump noise.

Will try to decipher the Italian/English manuals re: troubleshooting and testing tomorrow.

mick · Joined: 10 May 2015 Posts: 48

There are three black relay switches next to your battery on the right hand side ..... one of those is for the starter and fuel pump. They sometimes vibrate loose, try taking them out cleaning the connection and replace.
You could try swapping them around from one that you know is working, sometimes just flicking it with your finger is all it needs.
They are very cheap to replace ......I hope this is your problem.

quikduk · Posted: Mon May 27, 2019 4:07 am Post subject:

Mick,

Thanks for that suggestion. I just tried that and they are all good. I also checked ALL of the fuses and all are good too.

I may have a potential source after fiddling around with it a few minutes ago. I was reading the somewhat useless factory manuals and thought to myself, it can't be that complicated...assuming that the ECU is still OK.

quikduk · Posted: Mon May 27, 2019 4:11 am Post subject:

I was getting NO fuel pump noise and NO starter. Hmm. I just recently started this thing so perhaps it has to do with the safeties that MOM put in place to keep me from being stupid, at least when starting it...and it is FI so that would shut everything off right?

I sat on the bike just now and moved it back and forth to make certain I was in neutral. I put up the side stand, turned the key and PRESTO, fuel pump noise...but no start. I thought maybe it also involves the clutch interlock so I squeezed the clutch lever and PRESTO #2, it started.

So now my questions to you gurus out there are:

1. Is it the side stand switch AND the clutch interlock?
2. Can I permanently defeat both and if so how?

I recall a lot of Ducatisti having issues with the side stand safety and there was a way to either short it with another adapter harness or maybe it was to just wire the contacts together and remove the switch altogether...but I can't remember.

quikduk · Posted: Mon May 27, 2019 4:13 am Post subject:

Re: the clutch interlock, is that another handlebar switch that I think wires behind the headlight or is it down to the crankcase?

Maybe these were never working correctly and now they are. Either way, it still doesn't explain the dash turning on and off a couple times before this happened. I am certain that all of the dash wires are soldered and heat shrunk and they are tight as I just messed with the lot when I had the front end off.

I will check all of the grounds again but unless the dash was related to something else vibrating loose, I am not sure what gives as it all appears to work correctly...now that is.

Any suggestions?

At least I am thrilled that it starts once again as with 2 in college, I really don't have a lot of disposable income to fix it if it were more significant.

quikduk · Posted: Mon May 27, 2019 4:50 am Post subject:

After reading about a similar issue on the Ducati.MS forum, I will also check the ECU ground, the side stand switch connections and pin alignment with the "hole" and the clutch switch condition. It could also be a neutral safety switch but a switch either works or it doesn't so I find it more likely AGAIN that it is a bad connection or bad ground.

I'll follow up after I go through these areas.

2bims · Joined: 03 Apr 2010 Posts: 7289

I've had similar on Modern Bims......It can be a 2 issue problem.....Look under the clutch lever...there should be small steel "spring...which is just a flat piece of spring steel...that when you operate the clutch by pulling the lever....it clicks the teeny tiny button interlock switch that is push fitted on the underside into 2 small round holes on your clutch perch assembly.....Sometimes this metal strip goes awol and is incorrectly "bent" so that it doesnt allow the switch to operate....

Just remember that when starting DB5/DB6 etc...The clutch ALWAYS has to be pulled as a safety just in case you have left the bike in GEar….Its good practice on any bike to pull the clutch when starting to lessen the load on the battery/starter motor...There is also a plunger switch on the sidestand.....Bikes can obviously be started when on the side stand as you've done it before to warm it up...And once you jump on board and bob it into gear it SHOULD cut out straight away if you havent retracted the side stand....so that you cant ride off with it still down....hit a left hand bend and side stand cuts into the road and off you go....

So check first that the inadequate clutch microswitch is still in place....and its metal strap that operates it....it should just push.prise out of its housing with a small flat blade screwdriver because it just has split plastic pins locating and securing it...real nasty and cheap......and then you'll see a 1/2 inch x 1/2 inch plastic micro switch with 2 wires coming off it....This goes into your headlight housing....you can simply push the button on the end to operate.....There is a connector that is easy to pull apart in the headlight housing behind the instrument panel....so trace it back....happened on my Db6....I disabled it permanently....by simply making it On all the time...Or off I cant recall....but if you have an ammeter you can check the switch is working.
...And you can feed the wire back onto itself to make a circuit which is all the switch is doing....or breaking a circuit when the clutch is pulled....

I still have my sidestand switch intact and operating...but it can be a 2 issue problem ...the 2nd being with that....Take the LHS belly pan piece off...and you'll see the switch which is a black plunger.....again its a simple off/on switch...activated by the swing of the sidestand up or down....spray brake cleaner/electrical cleaner on to it...sometimes the plunger sticks.....Sort the clutch one first.....as a bike should start with or without the side stand switch....its only when you put the bike into gear that it should stall the engine if its working....I lot of people disable these as yes...they can operate when riding...fooling the bike into thinking that the sidestand is down and sticking out....and evidently when riding the bike is in gear...so ecu cuts the fuel flow and stalls the bike....I just like to keep the sidestand switch operating if I can....aged it is and me so I like the reminder....Both switches available at Ducati dealers....they'll probably tell you to disable both

2bims · Joined: 03 Apr 2010 Posts: 7289

Also check the "neutral" indicator switch which is on the back of the engine facing the swingarm....2 wires in a black casing....Because of its lovely location and bimota not fitting a mudguard...its prime target for crud and water to be thrown at it from the back wheel...the switches normally work...its simply screwed into the engine casing....BUT...the 2 wires that push fit onto spades on the back of the switch can corrode and loose contact....peel/pull back the black rubber cover and pull the wires and check and clean the spades and connecters

2bims · Joined: 03 Apr 2010 Posts: 7289

Also check the "neutral" indicator switch which is on the back of the engine facing the swingarm....2 wires in a black casing....Because of its lovely location and bimota not fitting a mudguard...its prime target for crud and water to be thrown at it from the back wheel...the switches normally work...its simply screwed into the engine casing....BUT...the 2 wires that push fit onto spades on the back of the switch can corrode and loose contact....peel/pull back the black rubber cover and pull the wires and check and clean the spades and connecters

quikduk · Posted: Fri May 31, 2019 10:32 pm Post subject:

Thanks for the info. I'll check these items out this weekend.

quikduk · Posted: Wed Jun 05, 2019 9:49 pm Post subject:

So I tried a couple things the other evening.

1. I removed the SS switch/plunger mini-harness from the connector down to the stand including the bracket that are located on the left side. There are 2 yellow wires to the switch and 1 blue/white and 1 brown/white wire that go to the relay on the right side of the tank.

2. I tried the "jumper" thing from a Ducati forum except that those SS switches apparently have 3 wires coming out of them. Needless to say that this "jumper" did not work with the relay removed as while 2 pins on the relay are for the SS switch interlock re: the starter motor working or not, the other 2 pins are for the fuel pump relay. When I jumped the first 2 pins, I got starter motor but no fuel pump. When I jumped the second 2 pins, I got constant on fuel pump so I cleaned the relay contacts and reinstalled it into the socket. Interestingly enough, the bike now starts without the SS switch plugged into the harness.

3. I noticed that the prior owner had installed the "drop pin" 180 degrees out on the ASV clutch lever and had...used a micro zip tie to contact the clutch interlock switch plunger...WTH? I removed the lever...and offending zip tie..., cleaned and re-lubed and rotated this pin 180 degrees, then reassembled everything. The pin now contacts the plunger on the switch and presses it into the switch body but not fully. I still cannot start the bike in gear without the clutch pulled in so does that mean that the NSS is operating correctly or does the clutch interlock pin need to be pressed fully into the switch body? I could disassemble the front fairing, find these wires and test my theory with an ohm meter but that might be a wasted effort so looking for prior experience with this here.

I still need to find time to ride it to see if anything else surfaces so maybe Friday on my way to work...but I'll have to bring some tools JIC.