Ariel Owners Motorcycle Club

Hi

New to the owners club, just aquired a 1954 Areil Colt, have a small problem in that if the bike is not stared for awhile the oil appears to drain down into the sump, guess when the level reaches the the crank shaft bearings there is a small weep hole on the alternator side where upon it starts to leaks out. Assume it is bypassing the pressure relief valve to drain down and would return if started. However there appears to be no crankcase vent so if started would force more oil past the oil seal or is this normal and the oil seal has just failed.

Any info on this would be much appreciated.

Colin

It is much the same engine as a BSA C-11( only a bit smaller and an alloy head. The gear type oil pump generally allows oil to pass through it (when the bike is left sitting). Use minimum oil in tank if you can accept that fix and don't do long trips. Nev

Colin,

wet sumping - as this is called - is generally not welcome. At best it means blue smoke and burning oil until the sump clears, at worst it can cause expensive damage because oil is far less compressible than air, and if there is too much oil in the crankcase then something has to give... Oil coming out of the breather (the hole in the crankcase behind the altenator) sounds like there is a lot of oil collecting in the sump. How long is the bike left standing before it reaches this point? hours, days, weeks, months?

The cure is straight forward, assuming that the oil pump is sound and not leaking oil (either through it's faces or gaskets). The cause is usually a poorly seated non-return valve on the pressure oil feed. On the RH crankcase immediately below the points cover is a bolt head with a fibre washer. The bolt is hollow and contains a small lightweight spring (like one from a biro) and a ball bearing. This is the non return valve for the pressure oil feed to the main moving parts in the engine (crank bush, big end bearing). The ball bearing sits against a small orifice, and is held in place by the spring. Check that this is the case - if not then that's the cause of the wet sumping. If the ball bearing and spring are in position then it might be that the face of the orifice needs cleaning or refacing. Easily done but more of that later.

I suggest you spend £10 on an original manual for the bike - it will show you all these things in diagrams. here's one (no connection to me!)
http://www.ebay.co.uk/itm/Ariel-Colt-LH ... 3a9217aa34

Nev / Paul
Thanks for the info, normally after about a week standing then oil starts to appear into the drip tray from the vent hole. Just received an owners manual and can see the valve you are talking about. Have drained all oils at present (engine, primary chain case and gearbox) ready for new oil, will check out the valve you mentioned.

Many thanks

Colin