Ariel Owners Motorcycle Club

The rocker boxes drain down the pushrod tubes. I suppose one of the rubbers
could be the cause but I can't think how at the moment. On the later engines
with enclosed pushrod tubes I've had real problems with oversize rubbers
further swelling and crippling the pushrods as well as flooding the top end. Grrr
.

Is the oil returning to the tank as frothy bubbles/little spurts or a constant stream? If the latter there's a lot in the sump which will cause smoke until it clears.
(As an aside - I'm sure you're running the bike on the rear stand - my VH would smoke like billy-oh after a few minutes on the side stand with the engine running, when everything was hot....)

Oil will gather in the head 'pockets' but I've never seen it get anywhere near the tops of the valve guides.

SG

Oil should NOT accumulate in the rocker boxes. They drain quite freely. The standard pump is the small delivery plunger. The only times I've had a smokey engine the return pump was faulty. Put a new ball in and check the little spring. The tapered ones are the best. Check it when off. It should POP clearly. IF you are very unlucky the return pipe may be cracked letting air in . Nev

Hi Nev/Will
I took the pump off and there appears to little resistance when covering the top port and pulling the plunger out, no pop as such. If I cover both ports there is a good pop, but the workshop manuals states to cover the top port only. Measuring the plungers, the larger of the two measure 0.3750 which is right at the limit of wear. The smaller measures 0.250, which is odd as the manual says 0.1870. I think the maintenance manual must be wrong. Does anyone have the correct size for the smaller plunger?

Simon.Gardiner wrote: Thu Dec 21, 2023 11:08 pm Is the oil returning to the tank as frothy bubbles/little spurts or a constant stream? If the latter there's a lot in the sump which will cause smoke until it clears.
(As an aside - I'm sure you're running the bike on the rear stand - my VH would smoke like billy-oh after a few minutes on the side stand with the engine running, when everything was hot....)

Oil will gather in the head 'pockets' but I've never seen it get anywhere near the tops of the valve guides.

SG

Hi Simon
I seem to recall that it was more of a constant stream, and that did surprise me as previously it was little spurts. If as you say it is because there is a lot in the sump, how long would you think it should take to clear?

It'll take as long as it needs to clear depending on how much is in the sump! (Although minutes rather than hours, maybe around 5 if that helps).
Alternatively loosen the sump plate bolts and drain off what's in there.....

SG

Your oil pump sems to be one of the later ones. I'd expect yours to have a delivery plunger
3/16" in diameter. Oil pumps usually have their year of manufacture stamped on the
inside face.

If there has been oil draining down whilst the bike has been standing then there will be
lots of smoke for a while - sometimes quite a long while. In my expedience it's unusual
in single Ariels for the oil to drain down appreciably even after standing for weeks.

There was another thread on this forum about the amount of oil to expect to find in the
sump - worth searching for.

Anyway, try draining the sump.

Now reassembled, and running. I can confirm there is a constant stream of oil on the return into the oil tank. So much so that it filled the oil tank up requiring me to drain some off.

I will drain the sump tomorrow and retry.

At least I can rule out the oil pump! It is stamped 1949, so yes, a later one.

I did remove the sump a few weeks ago as I needed to replace the gasket which was leaking. No real loss of oil. However, the engine was drained down at that time. I refilled immediately prior to starting, so I am at a loss as to how the oil has found its way into the sump (if that is correct).

Now reassembled, and running.

With or without white smoke?

We need to know.

Sorry Guys, with lots of white smoke.