Adjusted chain tension and rode. Chain is well oiled. I can rule out chain tension. As I take up drive from rest, the drive train snatches badly, causing me to almost stall. As I get up a little speed (not much) it continues to snatch, impossible to proceed, but when I pull in clutch lever some of the way slipping the clutch the snatching eases off, enough to allow me to move on at slow speed. Seems like drive train. Clutch-related, What do you think, plates? I have been running 10w 40 semi-synthetic engine oil.
What you are now describing sounds like grabbing, where the plates stop slipping smoothly as they take up drive and suddenly lock together, causing you and the bike to jerk or lurch forward. Does that sound right?
Clutch grab isn’t something you’d normally associate with a wet clutch though. Ducati do recommend any high quality fully synthetic oil of the right grade for these bikes but I would suggest using a bike specific oil as modern car oils have friction modifiers in them that are likely to cause slip with a wet clutch. Presumably this is something new that wasn’t happening before the pickup change. Once the clutch is fully engaged, is the bike impossible to ride slowly without slipping the clutch? Have to say this is pretty normal - the engine needs to be super smooth not to snatch at low speed. Ignition and carburation would have to be spot on to prevent it. @Arquebus is very knowledgeable regarding these engines...
Could be that; i can add that the gabbing isnt confined to taking up drive, it continues as i open up and will not die away.
Right then i’m convinced. Muchas Gracias! i’ll have another go at the pick ups’ gap and timing. I did take great care, and set gaps at 0.65 mm, alongside alignment of timing marks. Perhaps the timing mark alignment is not spot on due to viewing at an angle - plus eyes themselves are left or right dominant, would amount to error. I’ll triple check this time!
Upon further reflection: Although this occurred first ride after replacing the pickup coils, the bike did operate well for one mile without snatching. I had taken care to tighten the pickup coil mounting plate beforehand. This indicates to me that something has rapidly deteriorated over a short distance it seems, instead of an ignition pickup/timing problem. Nonetheless, bearing this in mind, I shall look into the timing first, re-test, then look into clutch as a matter of routine anyway. I'll report back, as a matter of interest. (might take a while, depends on weather and immediate demands). thanks to all for kind, useful help you've given me. Makes the task a cheerful and pointed one.
And there’s always the possibility of a faulty new component !, a friend of mine restored a norton commando, it wouldn’t run properly so he bought new spark plugs, still couldn’t get it running correctly, spent hours checking/changing everything, in exasperation he bought another set of new plugs, ran like a dream
Yeah, its hard to admit - damn frustrating when youve made up a new sheilded cable too - like a nightmare!
Checked the static timing, in no hurry. It's tricky to do in conjunction with setting the gap given the mechanism. The main problem was lining up BOTH coils at TDC. I had the timing correct, but one coil was further advanced than the other by a degree or so. I was going to file the coil bolt hole to ease it a little, but found just enough room in the play anyway with the bolt loosened. I opened the pickup coil gap to 0.75mm One perplexity is this: does the cdi (I guess it does) rely upon the static coil-TDC setting for the advance timing? On test ride, I experience the same symptoms, which incidentally I can confirm continued to deteriorate whilst riding last time - just noticeable, because it is so bad anyway, leading to a stall without slipping the clutch now, whilst at first it was more like threatening to stall. SO, I'm going to take a look at the clutch.
Where are you? These bikes suffer badly from carb icing... Problems can start as warm as 10c, depending on humidity etc
I’ve had that happen, low temperature damp air, starts running like a dog won’t tick over, wait a couple of minutes for the engine heat to melt the ice, runs fine, a mile down the road it’s happening again, not designed for cold miserable climates like ours .
Oh. Interesting. I have disconnected my carb fuel bowl to oil line heaters, because of a slight seepage of oil and the banjo thread length didnt like the thick 10 mm copper washers i had around. I’ll anneal an old one if i find one or thin one down and reconnect them and test. Im in Middlesex. It has been icy at night and about 5 C daytime. We had snow last week. Havent dismantled clutch yet. Ta for the thought most appreciated. Love you watching over me - if only because i want and try to get on top of all that has been needed - a fair bit, you know taking over a bike for reliability and performance, yet with children and aged parents to take care of at home at the same time! So I dont want to jump to conclusions and test them, I like to be thoughtful... Getting to really know the machine as i proceed this way is great. Never had a problem with ice and carbs before on Amals, SUs or Mikunis (latter on Suzuki GS)
