My 1995 916BP is long overdue a crankcase and covers refurb after years of neglect resulting in corrosion and bubbled paint. Big job I know, but a little task has stumped me...how do I remove the oil and timing inspection windows before blasting and painting? I can't see any mechanical way they are held in (like a nut or circlip) so I'm guessing they're press fitted from the inside. Tried some gentle pressure from the outside (don't want to break the glass) but no joy. Trawled the interweb but can't find an answer. Am I missing something? Anyone done this before and can share their wisdom?
They are indeed pressed in. When I've heard of people trying to remove them they usually end up breaking the glass. I guess if you heated the cover and used a suitable sized socket to apply pressure right at the outside perimeter you just might get them out in one piece. The part nos. are 254.4.001.2A for the oil level window and 254.1.001.1A for the timing window.
As above, i did mine a couple of months ago. I supported the outside of the cover and drifted it out with a socket. The new one i threebonded in place, despite it probably being unneccessary
Maybe a daft question, but why not just mask them with some card and proper body shop quality masking tape?
I have removed a couple and found that on some if they have been in the casing a long time they tend to shred around the edges of the rubber seal that envelopes the sight glass. As above I just drifted it\them back in when the time came and used some silicone sealer. If you drive them out squarely they should come out fine, I have never had a glass crack and they seem pretty robust from my experience of knocking them in and out. On the alternator side be careful not to damaged the tiny pip that serves as the timing mark. On that side it's very difficult to use a round drift or socket as the the little pip gets in the way and makes a snug fit around the edges of the seal difficult. The worst that can happen is you end up having to buy two replacements.
Thanks for the info guys. Yes indeed, the plan is to shot blast the corrosion. Suppose I could try masking them but just a bit worried that I could end up with frosted glass and/or shredded seals so if it's not too difficult, best to remove them. Red, thanks for the "pip tip". I'll try drifting them out and if I break them, at least I have the part numbers, thanks to Derek.
I shot blasted both side cases of my Monster engine, left both the timing and the oil 'windows' in. Used masking tape and no damage to either. Nothing really to lose if it does get damaged as you'd likely need a new one anyway when it breaks on the way out...
Thanks Duke. Thought I had an action plan based on previous feedback but now I'm confused again. As ShakeyWilly would ask...To Mask or Not to Mask: That Is the Question. I'm not an engineer or mechanic, just a home bodger, so here's my thinking on masking. Either it works or it doesn't. There's no "it almost worked" or "lets try that again". If it doesn't work then the blaster has toasted my glass and/or seals. But you're right, I could also trash it trying to drift it out so....what to do? Anybody know the approx. cost of new glass and seals?
The quickest answer is to phone a dealer and he will tell you and you will have the up to date price. If they are a common size across the range of bikes they may not be too expensive. The sand\ shot or grit blasting used when removing paint prior to powdercoating is quite harsh whatever is used, and it's likely\possible that if the masking is blown away or damaged you will end up with a frosted glass. If that does happen then they\it will have to come out anyway and if there is a lot of coating around that area they can be harder to get out. I have experienced that myself on one occasion. I would personally remove them when having the job done, which I always do, but it is your call. Don't forget they will also be treated to being heated in an oven, that won't do any masking any good either and it could leave residue from the glue on the masking tape baked on to the glass or rubber seal. I have seen that happen as well and it's hard to get off sometimes. Finally you will\should have a neater job if you remove them as if they are not very carefully masked it could well be noticeable and not look as neat as it could be.
Thanks Red. It's always great to hear from someone who's actually done it themselves and knows the pitfalls. I may be fussing over what could be a relatively cheap part (is there such a thing as a cheap Ducati part?) but better safe than sorry...they're coming out!
A wise move I would say. Masking up areas and powdercoating around them can leave a ragged edge due the the process and the thickness of the coating. I think you will notice a neater job.
