Monster S620 won't start - dull click

[toaster]

Hi - my son has a 2006 Monster 620 Senna and last week was on his way to work when it stalled and wouldn't start again. He had it recovered home and I just went over to check it.

When you turn on the ignition, all the needles scan ok and the lights sort themselves out - with just neutral and oil lit. When you press the starter there is a single dull click and the yellow Engine light comes on. All the headlights etc seem to be working but I've not checked the battery properly yet. Pressing the starter more times, just yields the same click and assertion of the yellow warning light.

See video at: https://www.youtube.com/watch?v=YkyNvcMlAFc

What does the team suggest?

T

[Darren69]

Check battery voltage and solenoid connections. If battery is below 9v ECU will fail, which may cause yellow light, otherwise you'l need to plug in to a laptop and read error codes. The starter circuit is not part of the canbus on that model I don't think, so if there is a fault there you will have to find it yourself.

[toaster]

I went to check the battery the other day and the voltage was 11.something. I put some jump leads on it and it started up fine and I let it run for a while. I then left it on charge overnight and my son rode it to work the next day without issue ... until ... he was about half a mile from home and it cut out again and wouldn't start. He said it was running roughly for the last bit and felt like it was idling too low and was going to stall at every junction (having had his last monster blow its engine he's understandably paranoid!).

What should I check next? Do those symptoms suggest the regulator/rectifier?

Ta,
T

[Darren69]

11v suggests a flat battery. What is the reading with the battery fully charged? Ideally it should be 12.5-13.0v or at the very least 12.0 to stand any chance of starting the bike. What is the battery reading with the engine running and revving the engine 2000-3000rpm for example? Should be showing around 13-14v to indicate that it is charging correctly. If it is not then you either have a dead reg/rec or no AC current running from the alternator. The 2 or possibly 2 of 3 yellow wires into the reg.rec should read around 30V AC with the engine running and revving should show the AC volts increase. You need to unplug the reg.rec for this and take care as 30V AC will give you a nasty shock.

I'm sure if you search on here there is some more detailed information on these checks and the static diode and coil checks, as this comes up often.

[toaster]

Thanks Darren - will check those next ...

T

[toaster]

Does the rough running (sorry, not got more descriptive info than that) gel with it being the batter and/or R/R?

[Darren69]

Could be either. You need to rule out the battery by full charging and bench testing over time. As I mentioned before if the battery runs low the bike will run badly with erratic instruments, fuel pump may not run enough fuel pressure to run the engine properly or with less power and then when battery drops below 9v bike will stop running as there is not enough power to run the ECU.

[Flip]

As Darren says, easy test first, charge the battery fully with a charger then with the motor running and a meter across the battery see what it's reading- do it both with the lights on and off (take care not to have too much fuel in the tank as you'll need to keep it propped up) and if it's not showing 13v-14v you need to go a little deeper.

Easy drop test for the battery is to disconnect it and rig up a 55w headlight bulb across the terminals and depending upon the amperage of the battery you can work out how long it should stay lit for and try it (if the battery is shot it will usually dim pretty quick).

Power (Watts) = I (Current- Amps) x V (Voltage)

So a 55w bulb consumes 4.58 amps so divide that by the Ah rating of your battery to give you a time (this is not actually the real time for a number of reasons as the battery depletes but it's a good enough guide for this test).

Here's a couple of pretty good links to doing some other electrical drop tests on the wiring:

http://www.aa1car.com/library/voltage_drop_testing.htm

http://www.fluke.com/fluke/uses/comunidad/fluke-news-plus/articlecategories/electrical/diagnosevoltdrop

[toaster]

Well having limited time and access I decided to gamble and get a new battery.

Bad news - it's not the battery :(

He got around 35 miles on it when it cut out again. I recharged the battery and last night went over to try some more things.

I started the bike of the freshly charged battery (that was at around 12.6v IIRC), it started OK. I put my meter on the battery and revved the engine a bit to the 4k mark or so. Nothing changed on the meter at all - there was not even a blip of a sign that the revving made any difference. Do I assume this means the battery is receiving zero charge at all and it is the R/R or stator?

Next thing I intend to do is this evening to try to check the R/R voltages as per above ...

Ta, T

[toaster]

Damn! So the good news is I now know how to use a multimeter to test a rectifier off a 2006 Ducati Monster, the bad (!) news is that it seems to be absolutely fine so I still don't know what the root cause is :( Is there anything else I can easily check/test/fix or should I just get it into a mechanic?

Cheers, T

[DrD]

Next port of call, assuming ALL the connectors in the charge circuit and battery earths etc. are nice and clean, is to check continuity/resistance and AC output from Alternator.

[Paul_]

Keep in mind that although your reg/rec tested ok on the multimeter it could still be bad. If your alternator tests ok then it'll be your reg/rec. Had the same with mine, new battery, alternator tested ok as did reg/rec. Changed reg/rec and everything worked again.

[Darren69]

What Paul said. If AC is working ok then maybe try one of these:-

http://www.ebay.co.uk/itm/New-Voltage-Rectifier-Regulator-for-Ducati-916-S4-Monster-2001-2003-/181795872767?hash=item2a53e0dfff:g:IfwAAOSw1S9Wb5M L

I have no idea if they are any good but they're a fraction the price of a new oem one so maybe worth a punt.

[toaster]

OK so the outputs from the stator pins was 18v, 4v and 0-ish so I guess we have found the problem...

[toaster]

Took it in today and they're going to sort out the stator coils which are the problem. They do say it fried the rectifier and that needs doing too, is that possible given I did the meter test and it seemed to check out fine? T