Won't start when hot

[jonzi]

My M796 won't start when its hot.

I had to stop for a pee the other day, and coming back to the bike, the thing wouldn't start.

Called the AA, waited 45 minutes for them to arrive, just before they did, I gave it another go and it fired up, the bike was cold by this point.

Slob, before he fell off, did a valve and belt change for me. At the same time the HT leads and plugs were replaced. Iridium plugs and magnecor leads.

Any ideas as to what could cause this?

[Luddite]

Sorry you're having problems, jonzi.

I see you recently fitted iridium plugs, (which I also have on the Evo). I don't know if you're aware that, because of the narrower centre electrode, you need to use a larger gap than the standard (on the 1100 Evo) of 0.7 - 0.8 mm.

For a good fat spark, 0.9 - 1.0 mm is recommended (I'm using the full millimetre).

If you haven't already done so, try a larger gap and see if that improves things.

These iridium plugs aren't as robust as standard copper-cored ones though so, if you do adjust them, use a proper adjusting tool on the outer electrode only. If you try to prise the electrodes apart, the centre one could break.

Hope you sort it quickly.

[jonzi]

Thanks for the reply!

Will a tool like this do? or do you suggest something else/better?

https://www.amazon.co.uk/Silverline-202148-0-5-2-55-0-02-0-1-Inches/dp/B00865SXQ4

[Luddite]

That tool says the flanged hole for adjustment doesn't damage the centre electrode, so it should be ok.

Mine is very old-skool, (I think it came from my dad's Ariel!). Does the job perfectly.

https://i.postimg.cc/4yPKf2Mr/WP-20190705-17-28-40-Pro.jpg (https://postimages.org/)

[rollo22]

There is this on at halfrauds

https://www.halfords.com/workshop-tools/tools/hand-tools/halfords-spark-plug-gauge-metric

[Tim88]

My 1100evo does this regularly! Leave it to cool down to three or two bars and it bursts into life as if butter wouldn't melt in its mouth. Ten minutes is usually enough. I am thinking that the rear cylinder oil temp sensor may be drifting out of its correct range? It is too awkward to get at to just swap it out at the moment, I'll wait 'til I'm doing some other task first, but I am at a loss. The problem can be really awkward if it happens after an accidental stall at the trafgic lights, particularly if you have just forced yourself to the front of the pack and are revving the motor to show how cool you are!

[Darren69]

I was thinking TPS/hot fuel mix maybe out. Looking quickly on Ducati forum I found at least one mention of that being the case.

[rollo22]

Could try the static TPS reset.

Start bike and walk away until oil temp is at 3 bars (don't touch throttle at all even when pushing starter button).

[jonzi]

Could try the static TPS reset.

Start bike and walk away until oil temp is at 3 bars (don't touch throttle at all even when pushing starter button).

And thats it? that's all you do to reset TPS?

I have the spark plug jobby coming, so ill do that and the TPS reset

Thanks all

[Luddite]

Yep - that's all there is to it. You might find this thread interesting as it covers the reset in a bit more detail.

http://www.ukmonster.co.uk/monster/showthread.php?t=55198

[jonzi]

Made the spark plug gap larger, and reset the TPS, then took it for a ride.

Bike restarted with no hassles after, so one or both of those did the trick

Cheers!

[Luddite]

That's great news, jonzi! Long may it continue.