Nasty tinking noise on warm engine
Posted: 13 Nov 2007 09:46
Dear all,
I bought a rather nice '79 strada recently, it's a very clean low mileage import. I drove it home and it pulled very well, better than my old K2 as I recall but the clutch was dragging at idle and there was no play at the lever. If you adjusted some play into the lever the clutch would not disengage. On inspection the clutch plates were glased and the thin friction plate had been replaced with a thick one. I fitted a new clutch pack but still could not adjust the clutch. Out came the clutch center and I found there was no washer or shim behind it! The raised rivets on the back of the clutch center had been happily wearing away the metal of the clutch basket! Luckily no visible damage had occurred to any supporting surface but what the primary drive thought about all that end float I just don't know. I noticed one of the clutch spring pillars had also been replaced but the clutch pressure plate lifts smoothly and evenly so this seems ok. Anyway I reassembled the clutch properly and shimmed it up. There was some rock to the basket, about .5mm at the edge with the clutch center removed, but very little afer shimming.
I have also cleaned the carbs and adjusted the tappets to 0.1mm, they were all about 0.25mm. The bike now runs ok and you can almost select neutral at a standstill. However as the bike warms up a tinking noise develops whenever the bike is not under load that is clearly audible at some distance. The noise seems in time with the engine and sounds like a very loud tappet. I have made the noise disappear occasionaly by operating the clutch but it soon returns. Using a screwdriver as a stethoscope the noise seems to come from the upper primary drive area but this is not a very reliable method. I have a Ducrappy and the noise doesn't sound anything like the horrendous clutch on that or like the clutch rattle on my old K2.
I've fitted new carb inlet rubbers and air filters. I was surprised that the engine no longer responds to the idle mixture screws unless you make it run on that cylinder alone when they set best at about 3/4 turn out.
Can anyone suggest any solutions?
Maybe I should write this up as an article for the mag... The pics of the damaged drum are rather good!
Thanks
Chris
I bought a rather nice '79 strada recently, it's a very clean low mileage import. I drove it home and it pulled very well, better than my old K2 as I recall but the clutch was dragging at idle and there was no play at the lever. If you adjusted some play into the lever the clutch would not disengage. On inspection the clutch plates were glased and the thin friction plate had been replaced with a thick one. I fitted a new clutch pack but still could not adjust the clutch. Out came the clutch center and I found there was no washer or shim behind it! The raised rivets on the back of the clutch center had been happily wearing away the metal of the clutch basket! Luckily no visible damage had occurred to any supporting surface but what the primary drive thought about all that end float I just don't know. I noticed one of the clutch spring pillars had also been replaced but the clutch pressure plate lifts smoothly and evenly so this seems ok. Anyway I reassembled the clutch properly and shimmed it up. There was some rock to the basket, about .5mm at the edge with the clutch center removed, but very little afer shimming.
I have also cleaned the carbs and adjusted the tappets to 0.1mm, they were all about 0.25mm. The bike now runs ok and you can almost select neutral at a standstill. However as the bike warms up a tinking noise develops whenever the bike is not under load that is clearly audible at some distance. The noise seems in time with the engine and sounds like a very loud tappet. I have made the noise disappear occasionaly by operating the clutch but it soon returns. Using a screwdriver as a stethoscope the noise seems to come from the upper primary drive area but this is not a very reliable method. I have a Ducrappy and the noise doesn't sound anything like the horrendous clutch on that or like the clutch rattle on my old K2.
I've fitted new carb inlet rubbers and air filters. I was surprised that the engine no longer responds to the idle mixture screws unless you make it run on that cylinder alone when they set best at about 3/4 turn out.
Can anyone suggest any solutions?
Maybe I should write this up as an article for the mag... The pics of the damaged drum are rather good!
Thanks
Chris