OK, now getting ready to put the engine back together, and going to repaint the clutch housing and alternator cover (plain, gloss black) before I do. Had planned on getting these grit blasted, though I have been warned against this, on the grounds that the blast media may get into places where it shouldn't - the chief risk I can see is the oilway to the oil pressure switch on the clutch side. I'm guessing that this could be masked off or protected in some way. Obviously, I will remove the alternator windings beforehand and the sight glasses one on each side should just push out from behind. There are a couple of other things that are a risk: 1 - the large diameter oil seal that the clutch hub runs in - will this push out? I'm a bit worried I might wreck it in the process. If so, is it a readily available part? Should I change it anyway (18,000 mile, 1992 bike) 2 - gearbox shaft outlet seal - can't be pushed out from behind that I can see - will it hook out with a pick, and if so, is it likely to end up damaged? 3 - the ball bearing race on the end of the alternator shaft. This looks delicate and easily damaged, also the way it is seated means it probably can't be pushed out from behind. I could possibly leave it in situ and protect the outer face with the cover (which needs stripping anyway) and maybe mask off the back? Has anyone done this and have any tips or advice to pass on please? The alternative is to use paint stripper (I have "new" Nitromors, and it isn't that good) and do it the long way round, which I have started. I've done that in the past (Multistrada alternator cover) and it took forever, and was never perfect when done. Or maybe I'm just being lazy! Time is an issue for me though. Any help appreciated. Thanks James
I have had good results with blasting paint and crap off aluminium surfaces with what are basically crushed up walnut shells - most blasters can offer something similar. At least if there is a bit of residue left somewhere, it doesn't abrade bearings etc.
The large seal is about a tenner. Buy SKF or similar not Ducati. The sizes are on the seal. The best way to remove bearings and seals is to use a little heat to help. Obviously watch not to melt the seals. I made a back board for mine bolted it on with gasket sealant to ensure nothing got in. Taped up or covered all the other bits. Blasted in a blast cabinet using grit. Aquablasting is the best way to clean them up as it is less abrasive than grit but my setup is not particularly powerful so I wasn't worried. Use a pick for that seal you talk of. It's got a metal ring in it so it's quite tight.
Try Soda blasting, it's much less agressive than other media and being soda fully dissolved with water or other liquids such as paraffin or diesel. I've had my Ducati single soda blasted and the finish on the bare cases and covers was great, without the tiny pick marks that other media sometimes leave. Many blasters are starting to offer this as an option, but take their advice as soda MAY be too gentle for stubborn paint removal. Don't mess around trying to mask off the alternator end bearing. They are only a couple of quid from a bearing factors such as BearingsRus.co.uk and it's not worth the hassle if grit does get in it.
