So my frustrations continue, after lapping the valves,(again.) thoroughly cleaning the carbs and having the Lucas Rita unit rebuilt I am still having major problems.
She starts fine and runs on both cylinders for about 30 seconds, then theright hand cylinder loses its spark, it is not the plugs as I have good spares, switch it off for a while and try again, same result.
Please don’t tell me it is the coils, have you see where the bloody things are?
It does sound like ignition - Ive never been a fan of Lucas Rita systems, preferring the Pirhana/Newtronic which just seem to work, the Lucas has always seemed a bit flakey. First thing to do is check the coils (unfortunately) try meauring the primary and secondary resistances to see if they are in spec. Then swap the coils over to see if the problem follows the coil. It could be something as simple as a duff plug cap which can be isolated by swapping over the leads and caps. I had a duff plug cap on an old 4 cylinder Jap bike in the middle of Spain in the 80’s it took ages to isolate the problem because we were looking for more serious issues with coils and wiring.
Moving parts to see which item the problem follows is really the only way
Russell
2 Likes
Thanks, however getting to the coils is nigh on impossible, they are tucked away under the steering head, how they got them in is a mystery and getting them out nearly impossible, as for testing them in situ also near impossible as they are stacked on above the other crammed up against another item which is also difficult to remove.
But thanks for your help.
I don’t know why people have a down on Lucas Rita, 44 years ago there was not much else.
Might be worth moving them to the easier maintenance position (like a T3, LeMans or Spada) under the LH side panel. Much easier to work on or swap out. I have seen them behind the steering head on some big blocks and it does look very cramped and awkward.
Given your issue I’d bite the bullet and move them as part of the diagnostics.
Russell
My coils are under the tank on a self made bracket, and both easily accessible with the tank off.
I had a choice of Lucas Rita or Piranha 40 odd years ago, I fitted Piranha because I had some bad feedback on the Lucas Rita set up. The Piranha system has been trouble free but saying that the bike has been off the road for over 20 years!
