Hi guys I recently purchased an old 748 engine to hopefully replace the one I have. I have already done loads to the engine, repaired the stator, removed about 4 rounded bolts, split the engine and removed all paint down to the aluminum for a respray. Mains and big end bearings seem to be good but I might as well replace these while its all apart. However I manged to break the one of the oil piston rings on the vertical piston while cleaning with a piece of blue roll I don't suppose anyone has a spare 748 oil ring they could sell me or point me in the right direction.
Is the piston/bore the original or over-size/aftermarket. You really need to measure the bore, accurately, first to be sure you get the correct size ring assembly. Once you know if the bore/piston is standard or an over-size you can then look for a replacement. Any replacement wants to be new in my opinion, (second hand rings will be "bedded" in to the bore they came out from & not your bore). I would also look to replace all three rings on that piston personally, others might have different views on this. Ideally that bore would need a quick hone too, to help the new ring/rings bed in.
I'm not sure that a 748 runs the same brand of oil control rings as a 900ss/900 Superlight but I had the same problem as you when I went to refit barrels, I broke a ring. I checked locally(Australia) for ring availability and was quoted $410 for a full set of rings and I only needed the oil control ring. So after hunting around I found the same brand that Ducati use (Caber Sri) available on eBay from Greece in all sizes(bore diameter and ring thickness) and the cost was $13Aust each. I hope that helps.
Thanks I have just seen this. I am still on the hunt for one. I can't seem to find any Caber Sri rings. The bore is 88mm and the oil ring is 3.0mm width
If it’s std bore, a oem set from Ducati isn’t that expensive. I would let a specialist take a look into the bore, before a re-hone.
