So that's what the noise is...

http://www.sweller.dynalias.org/images/shells080817.jpg

High mileage Moto-Fascista and the IoM conspire against me. Not 100%
sure what's caused the failure.

 

Using the patented Mavis Beacon "Hunt&Peck" Technique, sweller

Phoo-yuck.

I'd tentatively diagnose "having its tits thrapped off".

 

Is that a piece of your train?

 

No, big end shells of my Guzzi.

 

Ooh, clanky-clanky. How's the crank?
--
Dave
GS850x2 XS650 SE6a

"It's a moron working with power tools.
How much more suspenseful can you get?"
- House

 

No scoring - nothing visible or anything that can be felt with a
fingernail.

 

Stick some new shells in there and you're sorted! I would be inclined to
check the oil pump first however.

JB

 

That's what I'm going to do - not cheap though.

Big End Bolt 850/1000 30062260 ?13.16
I need 4!

And this from Motormecca:
Big End Half Shell Std. 850/1000 30062000 ?19.08

Does that 'half' mean each big end costs ?38.16, so both cylinders cost
?76.16?

The oil pump is a recent(ish) replacement (a year ago) off a low mileage
LM. I have an oil pressure gauge fitted and that returns a healthy 60psi
at running revs and temp, 20 or so at hot idle.

I suspect things are beginning to get marginal; high comp pistons,
improved head, B10 cam, open intakes and exhausts, light flywheel, arse
on the throttle - it's all started to expose the worn out bits.

 

Seconded. Of course he'll have correctly warmed up his ageing piece of
machinery (oo err) before the aforementioned thrapping.

P.

 

sparesGB charged me per pair not "half".

Ok. Thought I'd ask.

Having just killed another gearbox layshaft on the trike, I'll say the only
weak point on these _is_ transmission. My engine (Spada/LM2 hybrid) is on
277k miles on the standard bore but re-ringed at 177k. Big valves, P7/B10
hybrid cam, heeeoooouuuuge ports, PHM38 pumpers, *open* exhausts, edge wound
rectangular wire valve springs, lightened flywheel etc... The lump has benn
totolly relaible even with me giving it large for 19yrs. i don;t know of a
bike that would do better in my hands. I even killed my Jota.

JB

 

Mine's an ex-Spanish Police bike (1979 machine, retired in 1992) - I
reckon it's done 250,000 miles, 60,000 in my hands.

I re-ringed it on the original bores a couple of months ago - it ran iron
bores for a short time until it lunched the pistons, I went back to the
original Nickisel with a later set of LM pistons. The spec is more or
less the same as yours - I have PHM40s and some odd race valve springs I
got from Steve Wesson as well as the usual breathing mods.

It did have a habit of slinging its oil out until I re-ringed it.

It also has an appetite for bevel boxes as it's now on its third. I
think that's more down to my riding style but it's on the same UJ.

 

Nasty!

Boxerboy

 

I still had the original bevel until 224k when it became a trike. I have
done 3 UJs however. One in *spectacular* fashion. It actually split the
swinging arm when it exploded.
I'd still look to an oil or oil delivery issue if I had shells like that. Is
the pressure release valve jammed? Where is your pressure guage plumbed
into?

JB

 

Oil pressure light sender take off point.

I've got a sneaky feeling it maybe part of the casualty list from when it
ran low on oil and took out the pistons and cam followers July last year.

http://www.sweller.dynalias.org/guzzipistons/

Also, I think the oil I've been using over the last few years is simply
too 'thin' - semi-synth 10/40.

 

I'd say you're right. It looks like two instances of partial seizure to
me, possibly because the oil's running near the limit on temperature.

 

Christ onna fucking bike!

Certainly looks like it - unless there's a typo or other screwup on the
price list.
Yonks back I re-shelled my R80 and was pleasantly surprised at the BMW
prices - it was about 2quid a shell iirc. Made a change from utterly
stupid prices for small stuff in a BMW bag.
I came to realise - in fact, I'd always known it - that on some
engines[1] re-shelling should be considered a service item every 100K or
so. It tends to drop out of your consciousness if you're not doing it
regularly.

[1] Bus and train engines have it done routinely - the shells are a wear
item and it's a whole sight cheaper to replace them than a crank and
associated labour cost.
--
Dave
GS850x2 XS650 SE6a

"It's a moron working with power tools.
How much more suspenseful can you get?"
- House

 

I think I've mentioned that I always use Millers fully synth 20/50 or
Valvoline 20/50 'Racing' in mine.It does a fair bit more work than it did as
a solo, pulling 5 of us on the trike and often towing a trailer too. Runs
about 10-12°C hotter in oil temp than when it was solo. I may have to get
round to fitting the FOAD oil cooler I've got in the garage next. And a
remote oil filter too. And get the driveshaft dynamically balanced.....the
list always seems to get longer....

JB

 

IWHT that big-end shells come as a pair simply because they're a
precision item that has to be matched, but I don't actually know for
sure.

Guzzi spares are odd: regular service items are usually dirt cheap but
other stuff costs a fortune, which is why my recently(ish)
partially-rebarrelled Quota still has the original slightly pitted cam
followers.

 

I would have thought so too. All shells I've ever bought and fitted have
come as a a pair or set.

I'm currently making a jig to regrind/resurface the working face of these
cam followers on one of the tooling grinders at work. They appear to be
through-hardened rather than surface hardened from my first investigations
so I'll do a few of my old spare ones and see what they come up like. If the
pittting is not too deep I think I may be on a winner.

JB

 

It looks like it has been run low on oil at some point but then again
it's done a lot of miles!