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[Jerseyplym]

Hello everyone,
I'm back into the world of royal enfields after a few years out...
I've started an oil change on my (new to me!) 535 continental GT and had a few surprises!
-Teflon tape all over the main drain plug, and neoprene type foam used as a washer.
- front drain plug replaced with M12 bolt and bit of rubber to seal it
- Suction filter full of swarf, sealant and some orange stuff.

How screwed is the engine likely to be? The oil itself wasn't that old but looked like it had fine metal particles in it.

I'm planning to flush it with clean oil before changing it, and using dowty washers on the seals (had success with those before)
Is there anything else I need to watch out for?
For what it's worth the engine runs pretty sweetly!

[Haggis]

What's the miles on it?
Pickup strainer often looks like that at first 300 mile change. A magnet will tell you if its alloy swarf or something more serious.
Normal copper crush washers work fine for me.
Be careful when tightening up as the torque setting are not very high.
Main drain is 20nm and the pickup strainer bolts are only 6nm, same as the main filter cover bolts.
The front drain is a 12mm bolt but uses a copper washer.

[stinkwheel]

So how did they get an M12 bolt in an M8 hole? Did they do it with the engine out. Did they grease the drills/taps?

Possibly the source of the swarf?

On the plus side, filter may well have caught it all on the first pass.

Being pragmatic. It's still running. It's probably either totally ok or severely damaged. It's a bit like Schroedingers cat. The only way to find out would be to "open the box" and then you've had to strip it down. Is it a lot more onerous to strip it to check compared to stripping it to fix it after a failure?

I'd be tempted to fit a new filter, cheap oil, run it round the block a couple of times then check to see if any more's been caught in the filter.

It's the orange crap that would bother me more. A bit of alloy swarf will probably pass through and get caught by the filter. Anyone know if the factory use orange gloop or something that's been added later (maybe in an attempt to seal a stripped drain plug).

When I bent a pushrod on my 612 motor, it shaved curls of swarf off the side of it against the edge of the pushrod tunnel. All landed up in the filter, not seen any since.

[Jerseyplym]

Thanks for the quick replies,
It's at about 18k miles.

-Some of the bits of swarf were magnetic, that is worrying. The orange stuff was like a gasket type material or possibly dried instant gasket.
-It is indeed an M12 bolt in what's now an M12 hole - so it has probably been stripped at some point .
- One of the pickup strainer bolts is near enough stripped (the casing, not the bolt!) So I'll have to helicoil that. I've done a helicoil once before and it was a pain but it did work - does anyone have any recommendations for that?
-The oil filter was in reasonable condition, so my guess is the last "service" involved just draining the oil, replacing the filter and oil without cleaning the strainer which would explain how dirty it is.

I don't trust it enough to ride it but I've filled with fresh oil, got it nice and hot and drained it and it's certainly much cleaner and no nasties in the strainer.

It's a really great bike and much smoother than the new one I test rode when they first came out, it's a shame I've spent so much time undoing bodges!

[Wheaters]

I’d also do what’s been already said....change the oil and filter then drain and check it again after a couple of hundred miles. If the oil’s ok with no metal in it you could always reuse it.

It sounds like your bike has been worked on by someone with an adjustable spanner and a non-adjustable arm.

[stinkwheel]

- One of the pickup strainer bolts is near enough stripped (the casing, not the bolt!) So I'll have to helicoil that. I've done a helicoil once before and it was a pain but it did work - does anyone have any recommendations for that?

Yes, helicoil or you can also get timesert solid threaded insert collars. Chose your own poison, they go in in a similar fashion and you could argue which is better for as long as what sort of oil to put in a bullet.

if it's tight for space, you can get 1/4" drive tap holders chucks so you can use a ratchet and extension bars on the tap.

Probably not in a place you could drill and tap the holes to the next size up? Leave a wee surprise oddball thread in there for a future owner? (you can often wind an M7 tap straight up a stripped out M6 hole, they use a 6mm tapping drill)

[PeteF]

Is there enough thickness on the cases to fit a helicoil? I think you might be struggling. Is there room to go to m14?

[Jerseyplym]

Thanks again for your replies,
I will try a helicoil type repair for the strainer cap thread, thanks for the tip on the m7 tap but I'm not sure I would want to widen the hole on the cap much either.

Luckily the front drain plug although it's an M12 it's well tapped so no problems with it stripping or leaking.
Put a dowty washer on the drain plug and that's done up well too luckily.

As long as my helicoil goes to plan I think I've got lucky!

Once I've got it sorted I'll update this with how I've got on...

[Rattlebattle]

Stripped threads on the drain bolt heads is pretty common because the threads in the crankcase are not particularly strong. Whilst the dealers under the previous Watsonian-Squire regime knew how to prep a new RE bike properly, under the current importer there are a lot of new dealers who don’t appear to know how to look after these bikes which need a degree of care. I always use a torque wrench on these bolts because the torque values are quite low. The O ring in the filter plate can allow a small leak ( same on the main filter plate) I’ve had both, but the temptation to tighten the bolts a little to stop the weep is too great for some, so eventually the thread strips. They are not that solid and for this reason I only change the oil at the specified intervals ( mileage or time), not every 5 minutes like some do. There’s only so many times these bolts can be undone and done up again properly so why waste money on extra changes?
I’d have been aghast at what is on your filter when I did my 300 mile service, though sadly these earlier bikes were hand-built and owners have found bits of cloth and all sorts in them.
My guess is that whoever drilled out the thread did so in situ and that what you saw there is drill swarf.
These engines have quite a few narrow oil passageways that can easily get blocked. Also the valve lifters need a good supply of oil, supplied via passages in the timing side. You don’t really need bits flowing around the engine. On the plus side if you have a quiet, smooth engine then you probably have a good one. I’d be inclined to remove the faux tappet inspection cover, put a rag to catch oil and then start the engine. You should get a copious flow of oil from the rocker drain. (The oil is pumped up there directly through a small drilling in the crankcase mouth, through the barrel and head into the rocket assemblies then drains down the pushrod tunnel). The main oil seal in the outer timing cover should be changed at 12,000 miles. I bet yours wasn’t and if it were mine I do it-a simple enough job.
Whilst using el cheapo oil for test purposes makes sense, once sorted you should really use the specified synthetic, not mineral oil. These aren’t like the old iron barrel Bullets at all and need decent oil.

[windmill john]

Unless someone shoots this down as I do not know the exact layout of what is by the drain hole.
You could get a skilled engineer to weld the hole shut and tap a new drain hole/thread. This is what an engineer did at the cylinder head shop when one of my spark plug threads was buggered. He totally filled the hole, started from scratch and cut a new thread.
As I said, I don’t know of implications doing this on the sump, my welding is limited to arc!



John