turn the key, and nothing happens...

[docc]

2 minutes ago, Pressureangle said:

Not want to complicate things, but the clutch switch is only of concern when trying to crank in gear?

It is certainly put in there to prevent the bike starting gear and, unexpectedly, taking off.

Yet, an open Clutch Switch (or its open connectors) will prevent starter engagement regardless of the status of the sidestand switch or Neutral Switch/Neutral Relay.

[audiomick]

4 hours ago, Pressureangle said:

... the clutch switch is only of concern when trying to crank in gear?

 

4 hours ago, docc said:

...an open Clutch Switch (or its open connectors) will prevent starter engagement regardless of the status of the sidestand switch or Neutral Switch/Neutral Relay.

I'm with @docc on that. Coincidentally, I was looking at circuit diagrams last night in connection with this post

It stuck in my mind, because I had actually forgotten that it is the case, but on both the older and newer versions, the clutch switch (number 17, slightly to the left and below the centre of the diagram) is between the start button and the activation side of the starter relay. If the clutch switch is not closed (i.e. passing current), the starter relay wont be activated, and therefore the starter wont operate.

Edited October 25 by audiomick

[audiomick]

On 10/25/2025 at 4:30 PM, docc said:

[the clutch switch] is certainly put in there to prevent the bike starting in gear and, unexpectedly, taking off.

It occurs to me, that is perhaps not the full story, although probably the main thing. The other thing is, if you pull the clutch in when starting, the starter motor only has to spin up *half* of the clutch in addition to the motor. If the clutch isn't disengaged, the starter motor has to spin up the whole clutch and the input shaft in the gearbox in the cold oil.

To put that into perspective a bit: Martin Hagemann, the man in Germany for the small block models, had a dyno at his workshop one time for an open day. He wrote how they put a bike on it, I think it was his "cafe racer" build based on a V50 Monza. Whatever it was, they tested it with the motor warmed up without riding it, i.e. cold gearbox, and got a figure at the rear wheel. Then he took it for a ride and got the gearbox properly warmed up, tested it again, and got something like 5 h.p. more at the rear wheel. So the drag caused by the cold oil in the gearbox is apparently a factor. The final drive too, no doubt, which wouldn't play a role when starting, but still... 

Edited October 26 by audiomick

[docc]

5 minutes ago, audiomick said:

It occurs to me, that is perhaps not the full story, although probably the main thing. The other thing is, if you pull the clutch in when starting, the starter motor only has to spin up *half* of the clutch in addition to the motor. If the clutch isn't disengaged, the starter motor has to spin up the whole clutch and the input shaft in the gearbox in the cold oil.

To put that into perspective a bit: Martin Hagemann, the man in Germany for the small block models, had a dyno at his workshop one time for an open day. He wrote how they put a bike on it, I think it was his "cafe racer" build based on a V50 Monza. Whatever it was, they tested it with the motor warmed up without riding it, i.e. cold gearbox, and got a figure at the rear wheel. Then he took it for a ride and got the gearbox properly warmed up, tested it again, and got something like 5 h.p. more at the rear wheel. So the drag caused by the cold oil in the gearbox is apparently a factor. The final drive too, no doubt, which wouldn't play a role when starting, but still... 

That is an excellent point! 

[fastaussie]

On 10/25/2025 at 8:57 AM, Pressureangle said:

A couple easy tests- 

On 10/25/2025 at 9:15 AM, docc said:

This has been mentioned, but worth a review:

On 10/25/2025 at 9:19 AM, audiomick said:

For me, that is a clear indication to check that switch before looking any further. 

 

 

thanks heaps for all the tips gentlemen.  i was fooling with a few of my other bikes today, so i put the key in the V11 and it fired right up instantly like nothing had ever happened...