Dug my NTM 749R out of the garage last week for its MoT. It was running fine when I put it away in October, it's been kept on a CTEK charger and fired up occasionally to warm through and move the belts around. On taking it out, it had a major misfire, mainly in the mid-range: fired up fine (although died completely on pulling away a couple of times) and idled well. Runs OK at constant revs. But, when cracking the throttle open for an overtake, major misfire/drop onto one cylinder. If I back off and work the throttle open more slowly, the misfire slowly clears and then there comes a point at 7k+ when it just bangs back into full life. Slightly damp day, BTW. No error codes showing. Couldn't pull the plugs to check them as couldn't get a grip with the OEM plug spanner - I suspect that a previous owner may have fitted NGKs, which are a bugger to get out. Any thoughts?
Could it be the fuel pump solenoid? They corrode and cause all sorts of gremlins. Solenoid is located in the worst possible place at bottom of battery tray. Get a new one and relocate to the handy square rubber grommet position above the battery.
I knew what he meant ;-) Possible and a good point - but I'd expect a dodgy relay to affect running at all speeds, not just in parts of the rev range. Will check it though - I do keep a supply of spare Ducati relays, for exactly those reasons. I'm inclined to think either a little dampness in a coil pack or a little corrosion over the winter in the TPS. First step is going large with the WD40…
Indeed - specifically, a relay is a solenoid that switches an electrical circuit… …whatever, I'm having the bugger out
Stripped it down, pulled the coils, lots of ACF-50. Couldn't pull the plugs because my plug spanner can't get down the taper far enough, so stuck it back together and gave it a go: somewhat better but misfire still there. Next up is the relay - anyone recommend an online source for these?
Hopefully it's just stale fuel - I recall one of my R's doing that after being put away over winter - drained the tank, some new stuff in and solved
I was wondering about that - I ran the tank right down yesterday whilst testing, so will refill and see: however, all three bikes were away for the winter and this is the only one with any issues, so we'll see. I always try to put them away with a full tank, BTW.
I also keep them brimmed over winter, and actually got a siphon out to make sure I'd got rid of the old stuff - you should know the result within a couple of miles that way
Stored petrol in a sealed container does not deteriorate, but put it in a petrol bikes tank feeding an engine it will start to go off, as all tanks need to be vented to allow the petrol to be fed by gravity or a pump and as the petrol is used it needs to be replaced by air. The low temp volatile fraction is the first to evaporate off. I think it's the other chemicals within petrol that deteriorate and not the petrol itself if that makes sense. The gumming up comes from the ethanol, bacteria grows and wipes out pipework, glass fibre and plastic tanks plus has its own deposits too. E10 is now being introduced or introduced by now so expect issues to increase!
To save possibly unnecessary effort, I would definitely be obtaining a good plug spanner/replacing plugs before I tackled the solenoid/relay Technomad
I I ordered a supposedly thin wall socket off the inter web but it didn't fit, so I ended up filing the corners off the standard Ducati plug spanner that came with the bike. It did weaken it, so it split but the taper holds it together, so it's actually fine.
Yep, that's exactly what I'm finding. My order of play is: Drain and refill fuel tank; switch plugs; swap relays; swear…
