Okay, fired up the bike and the exact same issue. Super low RPM, opening throttle makes the exhaust noise louder but the RPM doesn't increase at all. Checked the timing and it's smack on for both cylinders. It also seems that both cylinders are working. I was pretty careful to get the wiring the right way round on the pickups as per the manual (when putting the pins in the plug that is) but maybe I have them backwards? I believe I have them connected to the correct ignition modules as swapping them results in a pop and no start.
I had the wires backwards . When I pinned it I was looking at the wrong end of the plug when comparing to the diagram. It's running now! Will get it warmed up later and adjust all the carb settings again. I think it was firing on TDC. Once it's warm and idling correctly, I'll re-check the timing but TBH, as long as it rides okay, I probably won't open it up again until it's next oil change. I wish these had a tac, I have no way of knowing RPM. My timing light doesn't have a readout. Fingers crossed that's it. I did a whole bunch of things I didn't need to but at least I learned a few things. Thanks for all your help.
Are you sure you don't have a blocked pilot jet in a carb? I know you rebuilt them but they can be fussy buggers, not sure if there is a vacuum to pressurise the float area and push fuel up that could be weak but do you find that thebike is 'flooding' on the weak cylinder if left running? that would indicate good fuel flow even at idle, where as if it's dry it would indicate starvation. One way to check is that when you open the throttle does it pick up straight away or you have to litterally WOT? if the latter then it could be pilot as when you WOT you go straight onto the main jet
There were a few issues. Original issue a believe to be dieing plug, perhaps with ignition on that side being slightly weaker. I changed plugs for iridium which created an identical issue. Again possibly ignition is slightly weaker on the lower cylinder. Third issue was me getting the wires on the triggers backwards. Causing bad running as I believe it was firing at TDC. It's currently running on both cylinders with a slight intermittent miss (though I didn't warm it up, so was still cold). It has an old OE plug in the bottom cylinder and iridium in the top. I have two new OE plugs on the way. I'll reserve judgement until I've warmed it, set the idle, synched the carbs and play with the idle jet. I need to ride it to know if it's actually one the way to being fixed, as it would drop a cylinder very noticeably at cruise. I don't believe carb is blocked as spraying fuel down it doesn't increase revs. I guess it could be flooding it but I don't believe so. If the issue continue with new plugs then I'll go back to carbs but at that point, I'll probably ride it to a mechanic.
TBH your level of mechanical sympathy sounds good, so if you are reaching your limit and thinking about taking it to someone, choose wisely... use a class act like some of the tech guys on here who offer advise, or go to a ducati specialist (albeit the symptoms are quite generic) the issue could well be that a mechanic see's Ducati and just starts with the wrong attitude. One thing I've not specifically seen, the ECU (or CDI) as it will be in this case. Have you changed it? tried changing it? I had issues with a 748 once where it would drop onto one cylinder, and got worse as it warmed up. EVENTUALLY we traced it to a ECU that had got damp, causing corrosion on the board and when it heated up the contacts opened up and caused havoc. I have an electronics background (of sorts) and the amount of boards we used to re-flow was pretty insane. If you can find or borrow a CDI it might be worth trying this, or even just leaving your CDI in a bowl of dry rice in the airing cupboard for a week or so, it's just another free thing to try as the issue could be even further back than the coils themselves
I've got plenty of experience working on cars (though all EFI) but this is my first bike. I did order new CDI units but Royal Mail lost them. I have swapped the ones on the bike around a bunch though and the problem was always the lower cylinder, so I ruled those out. I'm taking it to the place I did my direct access course to get new tyres and fork seals, as they also have a shop. Pass Bike. Super good people and their mechanic doesn't seem to have any prejudice. Fingers crossed it was the plugs all along and I just made it worse. Also hoping I got the timing close enough to ride okay (I really don't want to split it again). It's a crap system to be honest as it's difficult to adjust clearance without adjusting advance, not to mention having to deal with the oil and resealing the engine each time. If it needs adjusting, I will probably just get the unit below and adjust it in software: https://www.stein-dinse.biz/product_info.php?language=en&products_id=479825
The carbed Monster has 2 independent ignition systems, one for each cylinder. it is very easy to swap the coils and ignition modules although not so easy to swap the pickups. He has already swapped coils and ignition modules and changed the plugs. He has now changed the pickups and now has it running albeit with a slight misfire. Once it is properly warmed up and the pilot mixture adjusted if necessary it could be fine. Although as @Chris alludes, these bikes are very prone to blocked or partially blocked pilot jets which makes for a poor idle.
Now that I have ignition, I've checked for air leaks again and found one between the manifold and head on the upper cylinder. Unless my eyes are deceiving me, there's no gasket on that side. The one on the lower cylinder is visible. I have some choice words for whoever worked on this previously. Might explain why I'm struggling to get the carbs sync'd
@Cammmy you’ve had lots thrown at you and it’s good to read you have some progress. If it were my bike, and I think @Chris mentioned this much earlier in this thread, on a bike of this age I’d lose the Iridium plugs and go back to the original spec plugs.
Thanks. Got two new OE plugs on the way. The good thing about the bike Vs the cars is that I can have it half torn down and back together in an evening. Closest thing like it is the Tuscan, which is surprisingly easy to work on because there is absolutely nothing there that doesn't need to be (and probably some things that should be but aren't)
Reading through the issues you are having I think I finally understand why one of my favourite YouTube engineers - Alan Millyard has gone about troubleshooting his Pan European the way he has! On the face of it - he heard a slight engine noise and wanted to figure out what was causing it. His response to this? - Strip everything back to it’s component parts - check every single thing against manufacturers tolerances and reassemble the entire thing - it’s basically going to be like new. Alan is a legend and has an astonishing skillset. Truth be told he could probably hone in on the specific noise much quicker - but his methodical approach means he will probably avoid stripping and reassembling the bike over and over - finding and fixing one thing at a time. At first glance it seemed typical Alan overkill - but now I wonder if his approach is born from the experience of going through troubleshooting nightmares like yours one too many times! Either way - watching Alan’s stuff is super relaxing - so if you get to the point of wanting to set fire to the Ducati - watch some of his vids with cup of tea and a cake!
Ha ha, thanks. I'll check that channel out. Bike made it to the shop so will get them to sort the manifold gaskets while it's there. The lesson I've learned is that it can easily be multiple issues combined.
I've always run these engines with NGK DPR8EA-9 plugs. They are pre-gapped at 0.9mm (37.5 thou). The coils are well up to firing the bigger gap and it helps to prevent fouling.
Chris, DPR8EA-9 plugs are NOT iridium. There a standard old style plug but with a larger gap, the EA means a 19mm reach with a 'special' design' firing end construction, according to NGK.
Okay, this morning I got the manifold of. There was a gasket in there but a section of it was missing. Put it back together with a new one and tuned the carbs. I still couldn't get them them the same but it was closer. Sprayed everywhere below the carbs with carb cleaner and no change in revs, so I think it's sealed. Went out for a ride and it rode much better... for about 2 miles. Seems I have a new problem. The fuel can't keep up with the bike. If you let it sit for a while, you can ride a couple miles but then power fades out, it starts missing as well as backfiring. You have to stop and wait some more. I've checked all the hoses and none are kinked. as part of my previous troubleshooting, I've already put in a manual petcock. I've tried that in different positions, just in case but not difference. Also pulled the fuel filter and can easily blow through it. Thought it might have been contaminated fuel as I filled up as I left the house but the stuff that came out when I pulled the filter was perfectly clean (even pre-filter). I think the issue is either in my fuel pump or my carbs and it seems to have gotten progressively worse. I only did two things that I can think of to cause this. The first was disconnecting the vacuum line for the fuel pump from the manifold. I pulled it and checked again though, seems to be in good shape and held a vacuum when I sucked on it. Also, it didn't pull any fuel, so I'm guessing the diaphram is intact. The second is I moved the carbs around. I didn't remove them from the bike, just from the manifolds. So they were at various angles but nothing extreme an no fuel came out. It's also not leaking from the overflow. So if it's stuck floats, they are able to close but not fully open. How likely is that? Just from moving them a bit? I gave them a bit of a smack with a borrowed wheel brace while stuck on the shoulder but nothing changed. The fuel pump was getting it's source from the manifold with the vacuum leak. If it's been like that for a while, could the larger pulses from a properly sealed manifold have done it in? Any ideas on where to go next? Is there an aftermarket fuel pump for these?
Oh dear, sounds like I should strip down my Sons non starting SX50 as I’ve been trying to sort it since last May off and on. I suspect a seal has gone in the crankcase……now.
