So I pulled the bodywork off, fighting with some very poor fasteners in the process, and grappled with the exhaust. It (a) suffered from the nuts that hold the pipes into the cylinder head having seized onto the studs and (b) being unbelievably heavy.
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| Original exhaust studs with seized-on nuts (left) with replacement M8 stainless studs (centre/right). |
I decided to make replacement studs from threaded stainless steel rod, along with other replacement fasteners for the bodywork. The latter have a deep shoulder to protect the plastic panels. I replicated these with brass and aluminium tubing cut to length and then used as short sleeves butting up against the screw heads. The exhaust studs were very satisfying to do. But that's another story...
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| View of the rear wall of the engine case, showing three threaded holes for sump retaining screws. The rear shock absorber is visible behind. The center hole still contains the remains of a sheared screw. |
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| Swarf trapped by two oil strainers in sump. |
When I did manage to remove the sump, assisted by judicious use of a rubber mallet to break the gasket seal, I was extremely glad I had. The two mesh screens had caught some impressive looking bits of swarf. Of course, I wasn't at all glad to see swarf this chunky. Where was it from? So it was that I was set on a rather more serious course of inspecting the engine.
Removal of the bodywork showed up the rough state of the cylinder head cover. But that's another story ...
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| Flaking paint on cylinder head cover and rusty retaining screws |
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| My Trophy 1200 stripped of bodywork, exhaust and oil cooler |
2 comments:
How old is that swarf? Unless you heard/felt signs of engine self destruction on your ride home I'd be tempted to get some more miles under your belt before contemplating an expensive rebuild .... if that's what's on your mind.
What you going to do with that broken screw? Not a nice one that!
Watch that brass too. Brass and aluminium aren't happy bed fellows as I recall. Dissimilar metals, corrosion and stuff as I recall.
Thanks for your comments Sir Bostik.
I've no idea how old the swarf is. It could be from the manufacturing process. WIth the sump off, I've been able to inspect the condition of all the cogs in the gearbox from below. They are all mint. I've lifted the hatch over the starter and alternator drive gear so can check the condition of those too - they also look fine. I've had the cams out to do the shims and valve timing. Really good too. So I'm probably not going to strip the engine beyond this point.
In the end, I had to drill the screw out. It was a nightmare because of limited room. I couldn't preserve the threads in the case but fortunately there is a big swelling in the casting here so I could drill 7mm and tap for an M8 stud. This meant widening the corresponding holes in the sump, sump gasket and new centre exhaust bracket. All a bit of a fiddle but done now.
I've forgotten the term for corrosion between dissimilar metals but yes it's a bad thing. So copper grease will be my friend.
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