Square four 1000 4G

[DrewNolan]

Hi All.
No oil was getting to the rockers on # 1 and 2 .
The cause the oil gallery in the rocker spindle is full of carbon.
On the spindle there looks to be an alloy plug at one end on all spindles , there is no way of removing these using screw driver or spanner.
Can these plugs be drilled out to remove carbon from the oil gallery in the centre of the spindle and how do you put them back in, are they screw or press fit.
Thanks for your time.
Cheers Drew

[Brian.Fosh]

My Mk1 had similar but i can't speak for the removing the earlier spindle plugs as you ask. I used drills and various pipe/tube brushes from ebay. which also served to clean the crank oil ways.
What worked best in the end though, was a tip I picked on this forum, to use a bit of old inner brake cable with the end strands flared out.

I ran for the first 10 miles this year on Halfords Classic 20/50 oil. Green in colour, it resembles the old Duckams Q..Good I thought.
Bad move. It went black immediately despite having fitted a paper filter and a magnetic sump plug. The oil itself couldn't take the heat of a SQ4 and it was the oil that was carbonising, smoking in the head like an overheated frying pan after 3 minutes when I first ran up the engine to check the rocker flow.

I moved over to Morris Golden film SAE40,. (SAE 50 at present). After the next 300 miles, it remained golden coloured, ( a bit misty, like a cold honey.. but no sign of carbonising or blackness).
Then I stripped the engine 1000 miles later care of a spinning main journal bush. Remarkably, the whole engine was as clean as when I put it together.

Regards. Brian.

[DrewNolan]

Hi Brian.
Thanks for the time , am presently running SAE 50 .
Cheers Drew

[nevhunter]

If you think about it there aren't many aircooled 4 stroke motors out there except ride on lawnmowers. You won't see it mentioned on oil spec charts, but there are Aeroplanes and Harleys that need good oil. They both have some pretty high temp parts to look after. Head temps run to 230 degrees CELSIUS on aircooled aeroengines. I've used both those oils quite successfully over the years with no carbon and sludge problems. Lots of HARLEYS do long distances towing a trailer here (Australia) in high temperatures. That's a fair test. Nev

[john.bebb]

Hello Peoples; - Brian - thanks for views on the Halfords oil... I used to use it... but as the time has come for serious strip & rebuild (again)!
I shall be using Morris in my '49 Mk1

[simon.holyfield]

... but as the time has come for serious strip & rebuild (again)! ...

Again? Why?

[john.bebb]

Simon, - as mentioned in another post; - the gent who previously rebuilt it for me - despite my emphasizing the requirement - did NOT remove and clean the sludge traps... if you want anything done properly... do it yourself or pay someone who is well proven as to be capable & competent!

[Knud.Degnbol]

Sure!

[Brian.Fosh]

They are not so complex really, and rebuilding from running condition is relatively straightforward.
My 1500 mile rebuild took about 3 months of mixed feelings...

- 1 week of evenings and a weekend of re-assembly tasks,
- a few minutes of discovery that the face seal spring had detached and only the paper gasket was was stopping the coupling gears from munching it
- a couple of weeks waiting for minor bits
- (a day of helicoiling one stud in the head and pinning the main bushes)
- and around 10 weeks of disgust at how good the weather was.

It has now clocked 2500 miles and I greatly enjoy having a 65 year old bike that doesn't need to be at the back of the traffic queue


Brian..