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Discussion Starter #1
G'day All,
My sons 2000 750 F4 has developed a small starting glitch. Ignition on, in neutral and side stand down. Press the starter button and the starter spins the engine but the engine won't light off. Retract the side stand and it fires straight up and then the side stand can be lowered and the engine keeps running. My 2000 750 F4 on the other hand will start with the side stand down. We have delved into the starter diagram in the manual but from what we can see this just shows how the starter motor is disabled if the side stand is down and not in neutral and the clutch lever pulled in.

Ken.
 

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Sounds like a good starting point would be cleaning the side-stand switch.
 

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Discussion Starter #3
Sounds like a good starting point would be cleaning the side-stand switch. We substituted the side stand switch from my bike to my sons bike with no improvement. From what I can see on the starter system schematic, the side stand switch, neutral switch and clutch switch all disable the starter motor operation. This not lighting off problem would seem to be in the ignition or fuel system but we can't figure out how the side stand switch controls them.
The wiring diagrams that are so very well supplied by Donsy in his PDF manuals are coming up very fuzzy and unreadable.
 

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@ogrilp400: have you followed the starting system electrical diagnostics section of the service manual?


MV F4 750 String System Wiring.jpg
 

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Discussion Starter #6
Yes silentservice, we have done that, it would seem from that schematic that it shows how the various switches disable the starter motor system. My sons bike the starter spins the engine just fine so we are guessing that the problem is in the ignition or fuel supply. We can't work out how the side stand is interconnected to the fuel or ignition.
 

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Discussion Starter #7

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I would suspect the diodes or the neutral switch then.

Have a look at the engine running diagram and compare to the above diagram to see what drops out of the circuit when the engine is running.
 

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From the schematic from what we can figure the clutch lever switch is in the starter motor circuit. The starter motor works just fine, just either no fuel or ignition.
You are probably correct, but never underestimate the ability of Italian ( or English) electrics to do something odd!
 
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