Which oil?

for my CB72?

Simple enough I thought but I've just waded through an 11 page argument
on the 305 forum and I'm none the wiser.

So, twin cylinder OHC engine with a centrifugal oil filter?

 

The high film strength oils for diesel engines come in approximately the
right viscosity range.

 

How many deposits in the oilways?

If you get a modern high-detergent oil that's designed to keep dirt in
suspension this might cause problems, doubly so if you use a diesel
oil that's got an even higher detergent content.

Some basic oil of the right viscosity should do the job, if you're
properly worried use some low-detergent oil that's specifically
formulated for classics.

 

Bwaaahahahahahahahahahhaaaaa!

It'll be a long wait.

 

A *fucking* looooonnnnng wait.
<whisper an ex G5 owner....(1)>

JB

(1) yes, yes, yes...I have purged and flagellated myself for this venial
sin.

 

And I'm an ex-CJ250 owner. Lord, I have sinned.

 

Whooo-hoooo two bikes that are worse than the K4 I had.

 

Hey the K1-4 were fine bikes. How they got to the G5 and CJ
monstrosities I don't know.

 

In message

This was mentioned in the uber-thread on the forum.

Which is likely to be stupidly expensive, especially with the low
mileage oil changes recommended for this bike.


I see a cheap multi-grade Halfords oil in my future.

 

I haven't bought any in a while but I don't think they were that
expensive.

That should do the job, too.

 

Halfrauds Classic 20/50 (Duckhams replacement), comes in a green tin.
Suitable for most classic cars and bikes.

 

Over the years I've owned several G5s and one CJ, I remember spending a
whole day with various drill bits and a metal scraper carving out the blank
casting to take the G5 starter motor.

 

.... provided it's the correct viscosity. Japanese bikes have been
specified to use 10W40 for donkey, at least since the late 60s.

 

Try this lot.

http://www.millersoils.net

Failing that, I would have thought just about any 20w50 or 10w40 SG grade
would do the job. My only concern would be regarding zinc levels. A lot of
modern oils have very low ZDDP content. That site has a fairly interesting
pdf regarding low ZDDP and older engines.

Drop them an email, they'll be able to advise. Obviously they want to sell
you their product, but they do know a heck of a lot about lubrication
requirements for classic engines.

 

Yes they were. Although steadily less fine as the K number increased.

There was a K0 too. Actually, it was just a CB250 without a K number but
people started calling it a K0 after the K1 came out.

For some reason, the K1 had a lower compression ratio than the K0 so, to
keep the power output the same, they put a hotter cam in it. The cool mod at
the time was to put a K1 cam and rockers in a K0. Throw away the air filters
and up the main jet and, given a long enough road and your nose on the
speedo, you had a genuine 100 mph 250*.

* As attested to by the Rubery constabulary, don't ask me how I know this.

T.

 

I predict that there will be howls of protest:

In ye olden dayes I bought a Douglas (T35 Mk4) which had a very slight
amount of big-end wear, so I dismantled it, cleaned everything and put
it together with Castrol R40. (Yes, a bit viscous for the machine in
question - R30?).

After a year of fairly heavy use (Watsonian scooter sidecar and *HEAVY*
box of tools and spares to keep the bugger down on left-handers) I
thought it was time to bother Alpha with the crankshaft.

There was no more play in the ends than there had been when I got the bike.

And, oh! The simply divine fragrance...

 

Oily wrote:
Rusty Hinge whispered 'Douglas!'

Hum. Firstly, remove cam plates and selectors.
Secondly, pull a few links from a SOB primary chain - 5/16" x 3/8" one.
Place a selector in a 4-jawed chuck on a lathe, ventre the pin, and turn
down until a roller from the chain fits nicely, and turns easily.

Drill and tap pin and Loctite-in (or PTFE tape) a retaining screw with a
large enough head to retain...

Repeat on the other selector.

If necessary, with a chainsaw file, drawfile any rough or tight bits
from the cam channel.

Reassemble, and the gearbox will be as slick and positive as any you'v
experienced.

My Mk3 used to twist crankshafts: a touch of arc on opposite sides of
both ends of the crankpins stopped that...

Dragonfy with Mk series short leading link forks was the best-handling
bike I've ever ridden. With a souped Mk5 engine it was a very nice bike.

May I become an archaeologist? You'd be surprised how anaerobic holes in
the garden can be...

 

Thus spake Oily () unto the assembled multitudes:

Would it show on Google Maps?

 

Never did it again, but then, I can't remember any problems finding
gears... At one time (amongst other nice things) I had a Mk1, Mk3, Mk3
Sports, Mk4, Mk4 Sports, Mk5, Plus 90, Dragonfly and Trials, as well as
a couple of spare Mk4 or 5 ones. At least one of each Douggie made
post-war, and all running and testworthy.

But they would be ridden in a more

Sounds like a Mk1 or Mk3 with the old rear subframe. The later ones
bolted onto the bottom lug, which cured that fault.

/Thinks/ There must be lots of retired/unemployed miners about...

 

I don't doubt it - I also had (at the same time) a 1929 Mk1 KTT, 2 of
pre-war MSS, 1929 B29 two and three-quarter HP Douggie, ZB31 (plunger),
2 0f 500cc (Jampot) AJS, 500cc (Jampot) Matchless twin, D1 Bantam
(called Woooooorrrrh) and a big black Vin.

I think that was all.

The older forks were significantly stronger - grasstrack boys used to
use them , especially on their chairlots.

Ah. There was quite a deep hole next to my grandmother's house on what
had been a building plot before the war. I can remember the day it
arrived by air-mail.

Pop-pop-pop-pop-pop-p - - - - - - - - - - - - -THWUMP!

In the evening we went over - only lived a road away - and going in
where the front door had been, I looked up, and there was the sky above
the hall ex-ceiling innit.