New owner, new project!

[R.Nowobilski]

Hello!

I may have met some of you on a FB page where I'd recently shared my purchase, after getting a little carried away at an auction two weeks ago. It's now home!

It sadly hasn't come with any history, but one MOT from 1989 (test buy the people who supplied it new in 1950) and the V5 has been lost, it was part of a deceased estate. In the tool box there were some old manuals and there's even a hand pump on the side. I've poured some two stroke oil down the bores and it turns freely. The fuel tank still has some old 4* in it, but the line down past the tap has sludged up with some seriously stinky stuff. It's not stuck out my entire garage and gym with it. So needless to say that's an immediate thing to clean out.

Otherwise, the lack of history does mean the sludge traps probably need cleaning out. Combine that with the lack of cartridge filter means it's been run on old school oil.

My goal here is not a restoration. Quite the opposite. I've currently got a Bantam, which dare I say is over-restored. It looks like it's never seen a rainy road and I quite like the oily rag feel. That said I'd also like some reliability, so ignition may get some attention in the future, but in the meantime, I'm not thinking about buying anything other than a set of wheels (possibly with bigger twin leading shoes, if anyone has something for sale let me know!), tyres and replacing all consumables.

The question is, as it was ridden to it's MOT in 1989 and laid up inside since then and it's only got 7000 miles on the clock, I'd quite like to at least get it started before debating a full tear down of the engine. My dad's vintage bike engine builder (after uttering some expletives asking why I'd bought a SQ4) suggested getting it going on some vintage oil before converting it to run on multi grade with detergents and a cartridge filter. On the other hand, everyone on FB seemed to think the only option is a full tear down and cleaning the oil passages. Thoughts welcomed!

I'll be doing the majority of the work myself, I've rebuilt car engines, lots of i4 and V6, but this will be my first motorcycle and square engine.

[Roger Gwynn]

Definitely strip the engine given the history that you know, if not you run a serious risk of seizing the bottom end, breaking con-rods and smashing c/cases. It has happened too often in the past. By all means try to get it running for a few minutes but this will not tell you anything other than all the parts are there, you still need to rebuild the engine. The other main problem with the MKI engine is keeping head gaskets sealed, use the Otto gaskets and follow the instructions supplied and you will stand a 90% chance of keeping the lid on, otherwise it will be more like 10%. Line bore the main bushes, ie fit them, then machine in line with the roller mains. Fit a cartridge filter and use a multi-grade oil.

[simon.holyfield]

Welcome Ryszard!

[JohnnyBeckett]

hi , welcome to the AOMCC you will get all you need to know about your Ariel off the forum and the members a nice looking square four

[paul.jameson]

Roger's advice is sound.

Without knowing the history of the bike you have no idea when the sludge traps were last cleaned out, if ever. The lack of an external oil filter adds to the likelihood of full sludge traps.

An ex - Chairman of the Club and an ex - Square Four Spares Organiser have both run the risk with their sludge traps. Both paid the price of a blown up engine and new crankcases needed.

The cranks in my 4G were recently reground when I got them. The sludge traps though had not been cleaned out and were full to the point of blocking oil flow to the big end. You cannot account for the stupidity of a previous owner.

So clean the sludge traps and then you can enjoy the bike with confidence.

[nevhunter]

The same applies to the Twins. It's not worth taking the risk, with these plain bearing motors that centrifuge the sludge particles into a hard lump that has to be scraped out meticulously. Nev

[nevhunter]

The same applies to the Twins. It's not worth taking the risk, with these plain bearing motors that centrifuge the sludge particles into a hard lump that has to be scraped out meticulously. Nev