Paging the XS650 experts

There's an oil leak on mine, from the oil seal in the points housing on
the head.

Mine doesn't actually have any points, because it's an electronic
ignition model, so the housing is just empty.

Oddly, it doesn't leak all the time. I saw some oil by the left-hand
plug, whipped off the cover, thought: "Oooohh, that doesn't look
good...", and started it up. Sure enough, oil oozed past the end of the
cam. Ho hum.

I cleaned it up, and re-started the engine. No oil leaked at all in
five minutes' running, and none has leaked since.

I wondered if some oil had pooled by the seal, and then with the bike
on the sidestand, worked its way through. But it's been on the
sidestand for two days now, and it's still clean and dry. I know
sometimes oil seals weep if a bike's been standing and they've dried
out a bit, and they often swell as the oil gets to them and stop
leaking. Fork seals do it from time to time, in my experience.

Anyway, the XS650 has a ball and roller crank, so has a low-pressure
oil system, so it's not as if there's a helluva lot of HP oil squirting
around the top end.

The cam is supported in four ball races (*waves* at Guy Fawkes) and,
IIRC, the end housings (points left side, auto-advance right) don't
support it at all. I'm 99% certain that you can remove the housing with
the engine just sitting in the frame - three screws walloped with an
impact driver, and off it comes. Then whip out the seal, whip in a new
one, and replace the housing.

Can anyone confirm?

 

This is probably what it was. The old seal may have been a little hardened
over time and the heat of the engine and some oil flow has softened it up
enough to seal again.

Don't be deceived by the low pressure. It's pretty high flow rate though. If
you ever don't torque the cam oil feed banjo bolts up properly, the oil
*pisses* out in *qty*.

Correct. but alos replace the 'O' ring and gasket on the housing back face
too. (some had just O-rings, others a gasket too).

Also a good point to note on oil leaks, is being *bloody* careful if you
ever see a from the bottom of the oil feed tube at the front of the engine.
There is an adaptor/oil-pipe seating piece threaded into the soft ali of the
top crankcase. It is ****very*** easy to strip the thread out of crankcase
the you try to 'nip up' the oil tube bottom nut too tight without holding
the adaptor with another spanner.

With these engines oil quality is everything. The cam may run in 4 ball
races, but the rockers and cam lobes suffer very badly if crap oil is used.
On this note also, is to make sure both oil strainers/filters are clinically
clean. The one in the clutch casing is easy enough, but the magnetic one on
the inside of the front sump plate is prone to getting blocked and the brass
mesh getting ripped. These are often overlooked as most people seem to only
undo the two 27mm oil drain bolts when changing the oil (1)

(1) you may one day get a nice surprise on removing the rear magnetic drain
bolt. If you reomve it and see a sort of cylindrical piece of hard steel
attached to it, congratulations, you have discovered the only weak point in
an XS650. The engagement dogs from the 2nd/3rd gears!).

If you do keep it, we'll have to have a natter over a beer next time I'm in
Sutton. I *love* these engines.

JB

 

Noted. Good Mind you, the oil is coming out of the seal - visibly - not
the housing/head joint. It's now pissing out.... But yes, I'd better get
a gasket and/or O-ring too. The seal is now ordered.

Heh. I did just that with my first XS650, in 1981, having just completed
a top end rebore and rebuild. I was bolting on the oil feed pipe as
about the last task, and stripped the thread.

The air turned blue. In the end, remembering it was a low-pressure
engine, I cleaned up everything, did up the adaptor as tight as it would
go without then spinning round (ie: not very), sealed the joint with
Araldite, and re-mounted the oil feed pipe.

It was still like that a year later when I sold the bike. Didn't leak a
drop. I pointed it out to the buyer, and he wasn't fussed.

For the rest - yes, I'm aware of all the oil filter and gear issues.
I've had these bikes before, remember ;-))

Anyway, just been for a ten-mile pootle on it (yes I am keeping it, for
the moment anyway), and apart from the oil leak, it's gorgeous. Engine
seems mechanically slightly noisy - not rattles, or rumbles, or camchain
clatter, just... well, noisy, but then it's on the stock cans. In the
past, I've always used naughty pipes and never been able to hear the
engine at all.

Beer? Sounds good to me. Email me.

 

I eventually changed the top case to accept the monster liners for the
1153cc conversion.

Doh! I had indeed forgotten.

Me also. (Replace your last four words with "very much since"

Cheers, will do.

JB

 

Holy Jumping Jehosophat :-O What the ****** were you doing with that?
Was this a competition engine? Please tell me you used it on the street
))

I'm assuming you stroked it as well, because I *think* that about 900cc
is as far as you can go on the existing block and extra cubes have to be
obtained by modifying the crank.

Anyway, I've ordered the seal, gasket and O-ring (I had a rummage
through my old gaskets and I have some odd XS650 ones knocking around,
like clucth cover and a variety of O-rings, but (of course) none for the
housing. Cost of all components is under a tenner, and riffling through
the Haynes BOL confirms what we both thought - it's just undo three
screws, pull off the housing, replace seal, replace housing.

Of course, if it all goes tits-up, then I have a spare engine, too.....
I'm wondering what to do with the spare bike. It runs *beautifully* and
the lump has only done 15,000 miles, but the whole bike is shabby.

So I may break it.

What it *has* got is decent spoked wheels, and (correct me if I'm wrong)
I think XS650 spoked wheels are really in the want because the
customisers can lace whatever rim they want to the hubs (within reason),
whereas with alloys WYSIWYG.

 

It was used in my old TX750-lookalike 'street legal' flat-tracker. :>)

Halco modified crank/short conrods with large Mahle pistons and custom
liners (hence the need for a much modified top crankcase)
..

Nooooooo. Build it into a Rickman Metisse chassis. Piss of the
Morgo/Devimead-Bonnie mob a treat!.

All of the 650 chop builders want the spoked hubs. They are much sought
after. I had a pair of Borani (sp?) rims put onto a pair of XS2 hubs for the
flat tracker.

Nice easy beasts to work on the old XS650s. Possibly the ideal SOB?


JB

 

Got a pic anywhere?

Will an XS650 engine fit in a Metisse frame? Those frames are bloody
rare anyway. I *have* seen an XS650 in a Featherbed frame, tilted
forward because the lump is so tall.

Brilliant. They might fetch decent money, then )

The only bugger is having to take the engine out of the frame to lift
the head, otherwise I'd agree.

The engines are, quite simply, magnificent.

 

Not in it's final form. I may have a few photos from a rally back in 1984/5
when I took it out for it's first few runs 'in the white' prior to
plating/painting/finishing etc.
I got really short of cash just after I'd finished it so it had to go. Took
my Spada in p/ex + ££££ to a bloke who then went and wrecked it soon after
or so I heard.

It was just a guess. It would look nice though. It would certainyl fit in
the later Rickman Predator chassis. I built two of them. One Z1000, one
GS1000 based. Tons of room for a tall twin.

Agreed. In Spades. Mechanically _and_ aesthetically which is pretty rare
indeed. My old Jota looked amazing from the RHS, but with the alternator
hanging out on the left, it looked like real bodge job.

JB

 

Hmmmm... rather a large chassis, to be honest.

I'd like to see it in something like a Tony Foale frame - one of those
frames with the very large diameter main top tube.

Somewhere I've got a photocopy of an article in the US rag,
Motorcyclist, where they took an XS650 as a project bike. They wouldn up
with something that out-dragged and out-handled a DOHC Honda CB750F.
Looked good, too. I kept it for all the chassis tweaks and know-how.

That reminds me - I'd forgotten how shite the ground clearance is. Until
today.

 

The man *is* a suspension God.

Centre stand >>>>>>bin. New Konis. TR1/XV750 (I forget which) fork springs.
Job done.

JB

 

Hm. I think we're going to have to Take This To Beer (rather than email)
so drop us a line.

 

The Older Gentleman scribbled on the back of a napkin:

Hmmm.

How shabby? More importantly, how MOT'd?

CIHAGM before you start?

 

Well, all original paint, but faed. Exhausts are whole, but the
downpipes are rusty. Faded frame paint. Rusty fasteners. Perished tyres.
That sort of thing. But the engine is superb, it's all there, all
original, and unmessed-with. No tax, no MoT.

Sure.