Got a Moto Guzzi problem - Any experts out there?

[ruddy]

I just got this note from a friend with a '05 Moto Guzzi 750 Breva:
-----------------------------------------------------------------------------------------------------------------------------------------------------
I am dealing with a problem with my Breva 750 again. I got it out Saturday (March 22,2008) and went about 2 miles to a friends house. We were going to take a short spin. I got up to his house, shut the bike off and we talked for a while but when I went to start it up it would just crank over and over and over. There was no spark getting to the plugs. It has a coil for each plug. I had to roll it home 2 miles. Luckily it was almost all downhill.

This happend to me twice last summer (80 degrees) while I was on long distance rides. Fortunately I got it started after much frustration and and hour or so trying many different things, nothing seem to work. That was on the long distance trips.

Towards the end of the summer I decided to go for a ride. Pulled it out into the driveway (Cold about 60 degrees) and it would just crank over and over and over. No spark again. After a while while battery was almost dead it fired up and I went for my ride careful not to shut it off. Runs like a top when I get it started.

I got a new battery in February and I don't touch the throttle when I am starting it.

Anyway getting back to Saturday March 22, 2008. I got it home took the gas tank off checked all wiring and everything looked good. The next day put it all back together and it fired right up and I idled it for about 3 minutes and shut if off. Went to start it up immediately and it would crank over and over till I ran the battery down. GO FIGURE!
-------------------------------------------------------------------------------------------------------------
Do any of you have any ideas? Know some of you have experience with Guzzis, so I figured posting this here was worth a shot. We don't have a MG dealer in Spokane.

Thanks.

[Brooksie]

The first place I would try is:

http://www.mgnoc.com

Moto Guzzi types are there


Good luck!

[boxermania]

ruddy

A fascinating problem you are experiencing, certainly a knuckle buster if you have to push the bike everytime you stop.

I don't think the problem is Guzzi specific, so let me try my hand at it. Obviously it is electric.....the question is where is the source.

Let me sugest this:

Gain access to the coils, get a DVM (Digital Voltmeter) and clip onto the 12VDC source to the coils......when you turn the ignition switch to the run position, there should be measurable voltage to the coil(s) as you start the bike the voltage should still be available at the coil(s), start the bike and let it warm up for 4 or 5 minutes.

Turn the bike off, let it sit for a couple of minutes and try to start again, see if the voltage is present at the coil(s), during run and start.....I would guess is not there, that being the case you have a contact problem at the ignition switch.

On the other hand if the voltage is present, then your problem lies with the Hall effect trigger(s), the one that provides the trigger for the secondary voltage of the coil to discharge to the plugs. In any event, I'm certain that the problem is heat related, not ambient, but at the component level.

If the bike is in warranty I would take it to the dealer, if not, inquire about any recalls or technical bulletins on the issue.

Good luck and let us know how you made out......

[Airman]

Not specific, but the first thing that crossed my mind was that kill switch on the kick stand. Some BMW's used to have that sort of problem when the switch got dirty.

[boxermania]

Good call Airman, I must be getting soft in the head as I forgot that one.......

[ruddy]

Thanks for the replies so far. Good suggestions. I got a progress report today, so I'll pass on more info. First of all, he hasn't been able to duplicate the problem, because the bike has been starting up. Secondly, the bike does have clutch, neutral and side stand switches along with a bank angle sensor. The three switches appear to be working OK according to his tests with an ohmmeter. He'll check the bank angle sensor tomorrow.

In any case, the switches would prevent the bike from even trying to start, which is not what's happening when the problem occurs. His bike will crank, but it's not getting any spark. He can't bump start either due to the lack of spark. The battery is new and fully charged.

Any more ideas?

[redline999]

I know this is not very useful, but in the spirit of solidarity...

I have had one Guzzi, 1973 Eldorado, and every time I had a mystery "ghost in the machine" I could not get the problem to repeat at the mechanic's shop.

He'd charge me a couple hundred bucks, change a coil or rewire the harness, put in a new fusebox, etc.etc. and it would work great until I was out and the same thing would happen again. never diagnosed, never fixed, sometime they would just go away. Eventually to return.

The kick stand switch is great advice, I experienced that one myself with an 750 ninja I had...

Good luck! The moto guzzi is a fine machine, but she has gremlins.... i resorted to superstition and got a lot of mileage of of incense and I'd draw a ring of salt around the center stand and any oil spots ont he garage floor...seemed to keep this in balance. don't know why...ancient knowledge, I guess....

[Graf]

.....interesting....i just read about the same problem (different bike) on some other forum......the problem in that case was a faulty fuel pump....when the bike stood still for a while enough fuel collected (pulled by gravity) to enable to start the bike.....once you run it and shut off.....it's dry.....your pump may have an intermittent problem simular to this......or it maybe something totally different (i'd also check if the plugs are wet).....but what do i know.....good luck.