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Evening, Had my Falco for about 3 years or so now and always had an intermitent starting issue. It seems to happen after I've filled up with petrol. I'll return to the bike, put the choke on, turn on the ignition, hold the clutch in then press the starter. Sometimes it makes the initial electrical whiring starter noise but stops without turning the engine over. If this happens I turn the ignition off and on again and repeat until it starts, sometimes I have to epea this two or three times, but ultimately it always starts. (Touch wood).

It doesn't have this issue when started at home or work after its been stood for a while. Any ideas?

Hope I'm wrong, but that has the makings of a dodgy sprag.

No idea why it would only happen when hot, so hopefully I'm mistaken.

I wouldn't be using the fast idle to restart after filling with petrol, the engine should be plenty warm enough to start without it, but I can't see how that would cause your problem.

Are you sure whirring noise is the starter?

Could be a weak battery or gummed up starter solenoid.

In fact the more I ramble on it seems like it could be a combination of the battery and the starer solenoid. If the battery is weak and the solenoid has dirty contacts the starter might not turn fast enough to engage the sprag. You mention that sometimes the starter doesn't turn, but do you hear the solenoid clicking.

If the solenoid isn't clicking then have a look at the wiring for the starter button and the button mechanism for corrosion or potential breaks/wear in the wiring.

I had similas symptoms when I installed a HID headlight. It was prone to going out when I started the bike with the lights on. To avoid this happening I wired a relay into the starting circuit using the feed from the starter button to the starter solenoid to cut power to the HID bulb and reconnect after starting. Relays have a resistance and I reckon that at times it was drawing enough power out of the circuit to prevent the starter solenoid from activating, hence I didn't get the click.

new battery - and sooner rather than later

clean electrical contacts while you are at it

i would also suspect the starter solenoid..... probably worthwhile changing it if it is the original aprilia one...

oh, if you can - always use an optimate or similar :)

as pops says - no need for fast idle if you have just stopped for petrol....

one final thing to consider - is the bike alarmed???

Thanks for the pointers:

Battery was new at the beginning of this year and it continued to do it from time to time. The bike has an alarm but the optimate always gets shoved on it before I take it out to ensure the battery is tip top.
The wierd thing is it doesn't do it from cold, and even when its warm its intermitent.

I'm thinking this solenoid might be worth looking at, where would I find it and how would I tell if its knackered?

Thanks again.

Under the rear bodywork on the right, but it's unlikely that you'll find any evidence of a fault and I'm not sure they can be opened up easlily.

Still didn't say if you hear it click when it doesn't start.

If it does click then it could be knackered, if it doesn't click then the fault is probably in the wiring to or from the starter button or the button itself.

Alad makes raised a good point with the alarm, there have been a few instances of Datatool's screwing up. Mine's been no problem (touch wood) what's your's?

Can't say I've noticed a click, more of a wheezy cough if you know what I mean.

It does have a system 3 which so far (touch wood) has been okay.

I'd guess the whirr is the fuel pump priming.
I'd also guess the problem is most likely the starter relay or a problem with the starter switch .... this link explains for the horn switch but the starter switch is the same: https://www.ridersite.com/viewtopic.php?t=4269

could possibly be one of the other interlocks that would prevent starting - but check the above first.

.... ah .... and just noticed the Datatool system 3 comment .... some will correctly report they have never had a problem but there have been a reasonable number of those that have had problems ...

The thing that I keep coming back to though is why wouldn't it do it when its cold?

phillvr6 wrote:The thing that I keep coming back to though is why wouldn't it do it when its cold?

I just looked at my 1st post as I thought I'd covered that, but it appears I merely thought it and didn't type it.

I meant to put in a comment about iffy wires in the starter button circuit, if there is a dodgy/broken wire it is possible that when cold it is connected, but a gap can open up when hot. Long shot, but I'm convinced it's a problem with the starter button wiring.

Andy's button clean info is a good starting point and check for rubbed/pinched wires

Cheers, I'll have a look and see if theres anything obvious.

I'd replace the solenoid anyway, if only as a preventative measure for the future - OEM ones weren't the best.uture

Slightly random thought - are your coils ok? Stirring the detritus in the depths of the memory banks, I seem to remember something similar on the old BSAs and Triumphs way back when - re-starting & sometimes running problems when hot. Usually down to knackered coil and/or capacitor

How easy is replacing the solenoid? do I need to solder? If so, I think I'll be calling my friendly local autoelectrician.

No solder - all crimps

Very easy.

You need to take off the rear faring (gently), unclip a connector and undo the 2 wires (size 10 nut). Just be careful not to short the solenoid with the spanner

dyzio wrote:Very easy.)

dyzio then wrote:You need to take off the rear faring (gently)

Hmm, might just stick my head back in the sand, I'm sure it'll be fine.