primary oil

[Colsbeeza]

It is raining outside, so time to play.
I've had a go at measuring the oil volume in the primary, mainly because so much extra oil comes out after draining and removal of the outer case. I have attached a pdf of my measurements. Pedantism I know.
BTW the bike is on the Centrestand.
I think that 225 mls will overfill the level tube, but criticism is always welcome.
Col

[groily]

Couldn't possibly comment on volumes unless it's what's in a wine bottle (never enough), nor dare say a word about pedantry (!) - but pardon my gross ignorance, what does that pinion outboard the sprocket on the crank do Col?

[Colsbeeza]

Hi Bill,
Yep I am about to have a wine myself. That pinion is in preparation for me to fit the McFarlane Electric leg. Stephen fits it to your sprocket as part of his supply. I'll fit it after I am happy when the motor is run-in.
Cheers
Col

[rayjay]

That recess in the inner case makes it easier to fit the spring link

[Colsbeeza]

Hi RJ,
 Thanks for that explanation. I couldn't figure out what that was for. Quite apparent now really.!
Cheers
Col

[groily]

Quite apparent now really.!

Same here ref the pinion! Wondered 'bout that after asking. Gross ignorance reduced, curiosity satisfied - ta!

[BagONails]

It is raining outside, so time to play.
I've had a go at measuring the oil volume in the primary, mainly because so much extra oil comes out after draining and removal of the outer case. I have attached a pdf of my measurements. Pedantism I know.
BTW the bike is on the Centrestand.
I think that 225 mls will overfill the level tube, but criticism is always welcome.
Col

Hi Col, a subject dear to my heart having stripped and replaced the majority of my primary drive recently as you know. Unfortunately my original drain/level stand pipe affair has been replaced with a temporary 1/2" Whit. bolt and O ring after retapping the thread in the case. Luckily the thread has survived but the standpipe plug effort is knackered. I shall refer to your work here when making the new one, Thank you.

I'm wondering if the slight overfill comes about if you are filling and level checking with the bike on the stand rather than on its wheels? I notice too that you have an extra piece of wood under your stand so your bike is somewhat ass high / nose down. I think your red level line could be redrawn assuming the bike was on its wheels and this would put the bottom teeth of the clutch basket firmly in the oil and the tide mark of the oil level at the front of the case would move rearward. Hard to say what difference this would make at the standpipe position however.

It still seems safe to say that if the clutch and lower run of the chain are just skimming the surface then the chain will be getting plenty of lube. Checking the top run of the chain is wet through the fill hole seems a perfectly reasonable proof check to me at this point.

[Colsbeeza]

Hi Ian,
Yes the rear is raised a little. However, this would also raise the overflow tube, as it is a little further to the rear of the chaincase midpoint so less oil should have overflowed. I measured the gap between the rear tyre and deck at 18mm. Without the wood, the rear tyre almost touches the deck. This would make a small difference to the volume of oil retained, but my guess is only a few mls.
Certainly with a rider on board and rear suspension compressed would alter it further. All this would tilt the chaincase backwards, oil would move backwards, and increase the overflow volume even more. The oil would contact the chainwheel (clutch sprocket) more readily.
I marked the oval at chain bottom to see how high up the oval (see photo attached) the oil is needed, as you can see the oil level on the oval by looking down through the filler hole. The chain seems to be above the oil level I observed before in the Inset photo. But the slack is also at the bottom when running, so chain dips down further than indicated. (I pushed down on the top chain run to get the bottom straight for the photo).
Presumably, BSA would have assumed that any work on the chaincase would be on the centrestand, so may have thought that oil levels observed on the stand are not relevant to the chain level at bottom of the chainwheel.? So I think all is OK for 225mls.  *conf2*ing?
Col

[BagONails]

So how does your 33mm measured chain height compare to the height of the standpipe when assembled? From your 9+21 =30 from the outside face, the tube can only protrude about 10-12mm inside which doesn't seem enough, seems too short?

Another useful point of reference might be the first 1/4" threaded boss inside the inner cover going left to right along the bottom.  Maybe this can be seen through the filler hole with a torch and the oil should be just lapping up to or possibly over it?

[chaterlea25]

Hi All,
The length of the plug threads and standpipe is 32mm., 1 1/4in.
The pipe on mine is approx 20mm sticking up from the plug
I fill until it overflows then let any excess drain off for a minute or so then fit the small bolt to the plug

John

[Colsbeeza]

Ian, I could not see the boss you mentioned with outer cover on, but presumably it would be well under and not visible anyway?
Attached are some measurements I took this morning – a little more accurate (Vernier not ruler) with bike still on centrestand. I cut some of the gasket away to expose the inners of the chaincase more. Didn't want to install new gasket. Also a spirit level against the chain under the chainwheel shows that the chainwheel is much lower that the chain below the filler hole, and lower than I expected . Even more so with the bike off the stand and a rider astride.
John, my better measurements are now the same as yours. I think your standpipe setup is the same and probably to BSA standard, so unless you have a thinner drain plug boss and washer you are probably holding about 200-205mls after overflow on the centrestand. Fairly close to SRM’s recommendation.
Best I can guess is that the chainwheel skims the oil fairy well at that volume. BSA’s 225mls is dunking the chain a little deeper – probably more suitable in the 1950’s for a go-to-work hack.
If you are content with chain life, no point in changing anything!
Col

[Triton Thrasher]

Pedantism I know.

I think you will find the word is “pedantry.”

[Colsbeeza]

Hi TT,
I was trying to avoid pedoph---  You know what I mean.
Now I just had to look pedantism that up in Wikipedia -
Noun
pedantism (plural pedantisms)
(rare) Behaving or acting in the manner of a pedant.
Synonyms
pedanticism
pedantry (more common)
Pedantry does sound better.!
Col

[RogerSB]

Col, here's my humble opinion: I put this on here in July 2020 in a reply to someone's query, along with the picture attached below.

(Quote) A10 should be 225 cc (8 fl oz), my understanding is that the chain only needs to pick up oil when it's thrashing around.

If you look at the photo, the line I've drawn represents a horizontal level (not where the oil level will actually be).  If you look in the inspection hole you won't see oil covering the chain at that position but the level under the clutch sprocket (which you won't be able to see by looking in the hole) should just dip in oil to pick up a little and that'll be enough, as you don't want oil to saturate the clutch (end quote).

Col, I agree with everything BagONails says (reply 21) in that with your rear wheel being higher than normal it would cause the oil level to become higher at front and lower at rear inside the chaincase (compare the line in my photo to yours). Also as the drain/level plug is nearer the back than the front in the outer cover (with the rear wheel higher) the oil level could actually be below the oil level tube in the plug.

I also agree that the way to check the chain is being lubricated is after a ride and with a finger through the filler plug check its top links.

Rog.

[Colsbeeza]

Hi Roger,
Yes I accept that. Sorry I had not found your July 20 response. However, it does not explain my 200mls remaining after draining from the drain plug (160 + 42mls). If rear is higher on stand, there should have been no overflow, as the oil would tilt forward away from the pipe.
To add to your suggested check after a ride - if you burn your fingers on the chain then you may want to question the lubrication.
Cheers
Col