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Discussion Starter #1
I own a 2006 Brutale 910s. Lately I have been having problems when starting. It initially was labouring when attempting to start so I bought a new battery figuring that was the problem.

With the new battery now in (and fully charged) at times the starter motor wont engage when depressing the start button. However it will turn over as usual on other occasions. Everything else, electrical wise, seems to be working fine.

I was sussing it out more last night and I can start it without having to pull the clutch lever in! Yet it will still turn over when the clutch lever is pulled in and then not turn over on other occasions..

I assume there is a loose connection or problem with the clutch lever switch....

Any advice on this would be much appreciated....
 

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Discussion Starter #2
After more fiddling around I dont think its anything to do with the clutch switch.

It started a couple of times without a problem. Then I depressed the start button for about a second and the engine turned over. Then I pressed the start button again and got nothing. After several more attempts the starter motor isn't engaging and remains so!

Now I'm stumped....
 

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It appears to this reader that the starter relay needs to have two normally open switches in the closed position to supply a path to ground in order to energize the relay and supply current to the starter motor.

The two normally open switches are the clutch switch and the side stand switch. These two switches are wired in series. See attached diagram.

I would suggest you isolate the clutch switch and see if it is intermittent, and if so, correct the problem. Same with the side stand switch.

Since the bike has started a time or two without the clutch pulled in and closing the clutch switch, contrary to the intended function, I'd start here and be prepared to replace the switch.

Safety first,
Dick
 

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Discussion Starter #4
Thanks for the info Dick.

This might sound stupid (Im a real novice with electrical stuff!), but how do you isolate the switches to test if they are working properly??
 

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That is a fair question !

Good on you for asking the question. The only dumb questions are the ones not asked.

A few things one really needs to develop, and refine the development over time, is learn to always ask, "How does that work?" In learning how things work, you can learn how to fix it. Until one understands how things work, any attempt to correct the problem is lost.

I'd encourage you to collect several things before you go much farther.
1. Find a spare parts list for your bike
2. A chassis workshop manual.
3. An engine workshop manual.

These are all available on the internet. The cost is a bit of time searching and a bit of time looking up the parts and procedures.

I have attached a photo from a spare parts manual for an F4. Before I bought my 1090RR, I downloaded several manuals, and read about the parts and problems specific to MV Agustas. I also wanted to see if I could maintain the bikes. The manuals are very well developed. However, your specific bike was not one I took the time to gather info on. So, my diagram may not be exactly like your bike, you need to go find your bike's parts list, and compare it to the one I have displayed.

Notice part number 23, it is a switch mounted on the clutch lever. Notice the larger photo of the clutch, and one will notice there are two wiring assemblies, the smaller of which is the clutch switch, the larger is the combination switches like turn indicators, hi-beam, etc. On your bike, you will find the wiring assemblies have sockets and plug connectors within a few inches of the switches.

If you look up how to disassemble the clutch lever in your workshop manuals, you will be instructed on how to disconnect the plug from the socket without damaging anything. If you wish to proceed without instruction, you will sooner or later break things and you might as well just quit now.

If you disconnect the switch, you have ISOLATED the switch and now you can test it.

Learning a few fundamentals about electrical troubleshooting is no more challenging than learning to read, write, or use the internet.

Find a friend who knows how to use a VOM (volt-ohm-meter) you can buy a cheap one, you can purchase one at a Radio Shack store, for 20 dollars. 5 minutes face to face instruction will save me about an hour of typing.

Note: buy an ANALOG meter, they are much easier to "read" than a digital meter.

Now ask your self, "How does the clutch switch work". If you do not yet know, Google the question and in a few minutes you will know.

The answer is the switch is "normally open" no electricitly will pass thru the switch till you pull in the lever. It is a safety item, an important safety item.

If you hook up your ANALOG VOM meter to the switch, and pull the lever in and out your meter should indicate the switch is functioning properly.

If not, replace the switch. if yes, then move to the second switch, the switch connected to the side stand.

Look up the side stand in you parts manual, in your workshop manual, and isolate that switch.

This is how capable people troubleshoot circuits. You can do this, however, you need to have the will.

Alternatively, you can remain frustrated, or take it to a repair shop. The choice is yours to make.

Nothing ventured, nothing gained.

Best wishes,
Dick
 

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Fantastic explanation racasey - hope he finds the issue!
 

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Discussion Starter #7
Thanks Dick. Much appreciated. Will follow ur advice and keep you posted!

Regards
Ben
 

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Discussion Starter #8
Did as advised by Dick and both switches work fine.

I did notice that the top negative terminal on the battery was tight but it was rubbing against the battery casing. So I readjusted this top terminal so it wasn't earthing on the battery case.

I have not had any issues starting the bike since then. I'm wondering if that top negative terminal was the problem??
 
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