X9 500SL running issues

[richard9855]

Happy new year to all, I hope it will be better than the one we have just left.

I have a 500 SL that I have had for many years now as my second / town bike. Throughout the lockdown I think it has only been on the road about three times but I do run it to warm once a month.

Yesterday I took it out for a run, everything went well for a few miles (3) and then it died as I slowed for a corner. It restarted and would run but it won’t hold idle for more than a few seconds (5 - 10). It will start, not easily, and will run so I could get home but as soon as I rolled off throttle it would stop.

I filled the tank the last time I took it out probably October so the fuel is fresh.

Any suggestions as to where to start looking.

It has never let down in the 10 + years I’ve had it. I had to replace the oil pump just after I bought it and rebuilt the engine then but not had any major issues since.

Spent a small fortune last year and replaced all the suspension for OEM and had the seat recovered. If I can’t sort this and get her reliable then I may break her due to the complete lack of use.

Thank you in advance for any suggestions, they have always been very helpful in the past.

Kind regards

Rich Bell

[Dave Milnes]

My guess is probably electical as fuel issues are usually more when revving higher than idling.
I know you probably think the battery is fine but start there anyway and give it a charge and check the terminal connections are tight.
Then check all the fuses for corrosion especially the 4 hidden ones down to the LH side of the battery as these power the ECU/fuel pump immobiliser etc so an intermittent connection here can give weird symptoms.
Then check the kill switches for intermittent connection, work them both on and off a few times both with the ignition off and on observing their actions regarding the immobiliser and dash LED status.
Check the condition of the wiring and connector on the top of the fuel tank, the wiring here can corrode and become intermittent.
Also worth checking the connections to the back of the digidash on a 500SL.
When it stalled, did the immobiliser LED light in any way and did you have to kill the ignition and turn back on again before it re-started? Does the LED behave normally?
Did the analogue dash freeze when it stalled or did it behave as if you had just turned off the ignition as this indicates a total power cutoff, or just power loss to the engine systems ?
Did the engine die as if electrical power was lost or as if starved or over enrichened with fuel? Try a different spark plug and check the cap to HT lead connection.
It could be any number of sensors such as TDC, TPS, air presure, or just a corroded/dry connection to any number of things so short of going round unplugging, squirting WD40 and re fitting but before going into this depth of checking, try all the above easier stuff.

[richard9855]

Thank you Dave, I will check out your suggestions once the weather improves.
Your help is always appreciated and without it, I’m sure, there would be far less X9s left on the road.
Thanks again.
Kind regards
Rich Bell
HJ02VOO

[Gav]

Hi when I bought my last Aprilia Atlantic I knew it was prone to cutting out at low revs but would immediately restart and run OK until having to slow/stop-Admitedly
I lost a bit of interest probably had bought something geared again,and she stood in my garden over the winter, until I finally got it to a dealer and they replaced the spaghetti junction which was the wiring, however it was still doing it and they were on the point of giving up but the mechanic found a wire to the return(I am presuming crankshaft sensor-sorry cannot remember)connected to the CD1,was crimped, so he spliced a new one in and no more cutting out-

I did have ongoing issues with the ignition switch but that wasnt their fault, as I knew it had a cheap ignition barrel, but no immobilisor,at one point I had it running a Renault off a renualt barrel, had, also the pressure pipe burst to the injector, and then after replacing both inlet outlet ones,those,the electric connector to the injector worked loose.near to that dealers, but I limped home as  I had a spare, but it started doing that again just before it was stolen, dumped and written off.

Not my best buy!

I have to say my first Atlantic,be it only a Leader 125 but the later modular type that went right up to400/500 Sprints, was virtually trouble free over 10 years and I hope the Nexus I now own will be more akin to the former but with a better distance capability of course.

If you can check your wiring but that said I doubt I would have found the one on the Commander 500 Ape, in a month of Sundays, however if you have a similar fualt maybe it may be easier to detect if you are aware it is a possibility.

[Gav]

ps well done Dave for the ongoing Forum, I have missed looking in

[Dave Milnes]

What are you doing up at 3.30 in the morning!!

[Gav]

Night person me,years of unsocial work hours and shifts, mind you was back up at 0740 so hope to have an old gits nap this avder