Any ideas

[GuzziNZ]

So my 08 1200 Sport has had a few no start issues.
Wiring mode was done years ago and using 15 amp fuse.
Battery is 270cca and about 2 months old.
Bike is in use.
Charge rate is fine.
Pressing starter brings a clonk and blows 15amp fuse.
When I fitted new battery I also swapped around relays and have had no problems until today.
Went over wiring connections and earths.
Where else should I look, starter solenoid?

[guzzisteve]

Lots of ideas we just been discussing.

https://wildguzzi.com/forum/index.php?topic=117948.0

[moto-uno]

  Need a little more info here . The relay should have a heavy feed wire into it , this lead then goes to the starter relay after
the starter button is pushed . If this is fed by just a 15 amp fuse , it sounds rather inadequate to me . If that's the fuse for
the start button feed circuit , that's probably fine . Can you remove the wire that activates the starter solenoid and then check
for it's resistance to ground ?  Peter

[pehayes]

Just FYI.  Breva 11.   I had to create a simple bypass circuit with a momentary push button to bypass everything and go directly from battery to solenoid spade.  That circuit is protected by a 7.5 amp blade fuse and it seems to handle solenoid loads just fine.

Patrick Hayes
Fremont CA

[GuzziNZ]

Read the link and still haven't a definitive answer.
Went over everything again right down to removing starter solenoid. Waste of time as its sealed and you can't inspect contacts.
Multiple starts and just before putting bike away, clunk and bypass fuse blown again. What would cause this fuse to blow but starter not to spin. I hate electrics!

[fotoguzzi]

First of all, do you know the 15a is what is called for? The main fuse on a Norge is 30amp.
Probably not the starter solenoid but the wire leading to it is not given the power or the ECU is cutting it off as soon as the start button is pushed. Does The 1200 Sport have that goofy push the start button then let go and it cranks itself? If so the signal runs through the ECU. That’s why we talk about directly wiring to the solenoid with out going thru the ECU. as in the other long discussion here,

https://wildguzzi.com/forum/index.php?topic=117948.0

[guzzisteve]

The 15A fuse is at the end of the yellow wire, which is 12V feed to activate the ignition(starter) relay. In the starter interuptus mod you cut that wire and run a direct wire to batt w/fuse holder.  It also feeds the number plate bulb so you have to tape the end.
If you have the MPH mod it has a 12V batt wire w/fuse holder and diverts one side of the yellow wire at the pin connector.

EDIT:  Mentioned on a different forum that mod w/batt wire was done

That only leaves the button or the starter

My educated guess it's the computerized button 

[GuzziNZ]

Hi guzzisteve.
I am leaning towards the starter being the issue at the moment.
 
Yesterday after cleaning and checking all connections all I managed to achieve was multiple non starts and blown 15amp bypass fuses,
Today I removed 12v supply to solenoid and fitted a multimeter. On pressing start button I got 12.4v for 5 seconds before power was cut.
I am guessing this is because ECU didnt detect the engine running.
I then removed starter and I could be wrong but I think I felt the bendix gear return almost like it had been engaged in ring gear.
Hot wired solenoid, hot wired motor and then set it up to use solenoid to activate starter, all seems ok
Refitted started and bike fired right up. In fact it seemed to spin up and fire a lot faster than normal.
Go figure.

[guzzisteve]

Sounds like you found the issue. I'd pull starter apart & clean & lube bendix, clean out cover & armature. They are no fun to get things back perfect. Clutch dust finds it's way in.

[pressureangle]

Ohm's law says you need greater than about .8ohms to stay under a 15amp fuse at 12.4volts.
Measure the resistance of your solenoid and you'll have some data; if it's shorted to ground, it may still function minimally or intermittently. I don't have one I can access at the moment, but somebody should be able to give the nominal ohm reading from a known good solenoid for comparison.