dip stick oil level marks

This thread makes reminds me of the story of Goldilocks and the Two Bears.

baz said:

If I get the time I'll drain mine to the lower level and top it up to the max and measure the amount

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Don't forget to allow for the fact that the oil tank is tapered so the quantity required to fill from the 'L' line to the mid-point on the dipstick will be less than that from the mid-point to the 'H' line so measuring the quantity between 'L' and 'H' and dividing by two wouldn't be accurate.

maylar said:

I'm hoping not to have to do it the hard way. I'm sure someone has already done that.

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Even if they did, too many years have gone by. Triumph and Norton (maybe others) used the same oil cap so who knows what aftermarket caps have been used. So there's a range of marks so unless you've had the bike since new and know that it has not been changed and the person measuring also knows that theirs is original there is no comparison.

marinatlas said:

https://www.nortonownersclub.org/sites/default/files/2018-12/COMMANDO%20JAUGES_0.JPG

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Thanks for that. I guess there really is significant differences and I should measure it myself.

Thinking more about this I realized that if we forget the dipstick and measure from the top of the filler neck to where the highest we should have the oil, we would have a usable answer that hopefully would be accurate for all Commandos with the side mounted oil tank. Then we could decide how much lower is OK. This would eliminate dip stick length, different bike brands and after market parts made wrong.

Of course, then you could mark your dipstick.

The reason I posted this thread is that after returning from a ride last week I checked oil level and it was at the low mark. I added some oil and it came up to the H mark which is too high. I was pressed for time and couldn't address the issue then. Now its wet sumped a bit and the level is down. To bring it back I'll have to ride around the block to clear the sump, and that risks making a mess. I was hoping someone could tell me I need to remove 100 ml or whatever to get back to the mid point. Seems like trial and error is the only clear way forward. I WILL remember what those marks represent for the future.

maylar said:

To bring it back I'll have to ride around the block to clear the sump, and that risks making a mess.

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If "around the block" is as far as you intend to go then just drain about a pint or so from what's in there now and go for the ride (although the scavenge will probably have emptied the sump before you've left your driveway) then top up as necessary.

Hi,
New to this forum. I have only owned my now absolutely beloved 1976 MK3 Interstate since July this year. If I am supposed to introduce myself somewhere else on the forum please let me know. Anyway, having been reading through this Forum it seems a much better fit for me than a pretty pretentious U.K. one I am already a member of. On to the subject of how much oil there is between the low and high marks of the dip stick in the oil tank this is what I have found. If my bike is filled to the high level it spits oil all over the swinging arm and rear tyre. If I keep it midway between the low and high levels I have no problem at all. So having put too much oil in when I first bought the bike (filled it to the high level after warming the bike up) I syphoned off about a 1/4 pint to get it to just above mid range between the oil dip stick markers. At that point it’s totally oil tight and I would therefore guess it’s about 1/2 pint between the low and high level marks.

I carry a 12oz repurposed plastic bottle of PennGrade 20-50w oil on road trips.
It seems this 12oz will go L to H on my Mk3.
My dip stick is a new Andover piece.
Keeping the dipstick/cap tight eliminates one of my leaks.

Welcome, Big Phil.

Big Phil said:

If I am supposed to introduce myself somewhere else on the forum please let me know.

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No, you don't have to do that here.

Well that’s good to know I don‘t have to formally introduce myself Mate.

It seems we aren’t that much apart P400 on the levels between low and high on here with your 12oz compared to my 8oz so if we beg to differ it would appear that 10oz is the difference between low and high levels or at least thereabouts.

L.A.B. said:

Welcome, Big Phil.



No, you don't have to do that here.

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Big Phil said:

Hi,
New to this forum. I have only owned my now absolutely beloved 1976 MK3 Interstate since July this year. If I am supposed to introduce myself somewhere else on the forum please let me know. Anyway, having been reading through this Forum it seems a much better fit for me than a pretty pretentious U.K. one I am already a member of. On to the subject of how much oil there is between the low and high marks of the dip stick in the oil tank this is what I have found. If my bike is filled to the high level it spits oil all over the swinging arm and rear tyre. If I keep it midway between the low and high levels I have no problem at all. So having put too much oil in when I first bought the bike (filled it to the high level after warming the bike up) I syphoned off about a 1/4 pint to get it to just above mid range between the oil dip stick markers. At that point it’s totally oil tight and I would therefore guess it’s about 1/2 pint between the low and high level marks.

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Welcome Big Phil !
my guess would have been 1/2 a pint.

cliffa said:

Welcome Big Phil !
my guess would have been 1/2 a pint.

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Well unless you want to go delving into applied Science or Maths then let’s say it’s 9oz. End of the day from what I have read, my own experience and whatever dip stick variant is on your bike, keep it midway between the two marks and you can’t go too wrong. So my method is starting from scratch top up to the high level then remove 4/5 ounces. From there on I check my oil level after every ride to ensure it’s mid-may. So far after 700 miles or so of moderatly quick riding I’ve only had to add 50ml of oil which is less than 2 ounces.

me another fan o turkey baster ps my mom used one to suck boogers out of my baby brother's snout she called it the 'booboo snatcher"

If it's wetsumped and the level is now down to where you want it on the dipstick, why not just drain the sump ?

At your next oil service I suggest the following:

1) Drain the sump, examine and clean the gauze filter. Keep a catch pan under the now open crankcase, do not reinstall yet.
2) Drain the oil tank, make a drain "oilduct", direct the flow to a catch pan. If you don't have a history on the feed "filter" pull it, examine, clean and reinstall it with NEW sealing washers.,
3) Remove the "old" oil filter, catch pan here too.
4) Do something else for at least 2 hours, overnight is best.
5) Reinstall the oil tank drain plug; to be "PC" use a new fiber washer; to be practical...examine the "old" sealing washer, if it not cracked or brittle, look over your shoulder and reinstall it.
6) Put some fresh oil on the filter's sealing rubber and install it.
7) Reinstall the sump plug, good idea to use a new sealing washer, up to you.
8) Check the oil lines for abrasion, brittleness and tightness at terminations
9) Add 2.5 quarts to the tank.
10) Start the engine, run it until the head/barrel are too hot to hold your bare hand on.
11) Stop the engine, check oil level, should be a tad below the "L" mark. Add the balance of the oil slowly until the level is between the "L" and "H", this should consume the rest of the oil, but let the dipstick be the judge.
12) Go for a ride, bring a clean rag or paper towel. At the five mile mark stop, shut the engine down, check oil level, should be between the marks, no visible leaks.


Why care how much oil fits between the marks?????? If you add oil to the tank with a sump full of same without running the engine first you may want to consider a bulk purchase of air filters and Simple Green (or similar).

Cool? Or should I run for the hills?

Best.

"Why care how much oil fits between the marks??????"

Right! Per the manual, as long as the oil level isn't above the H or below the L, the oil level is "correct." Put the bike on the center stand to ensure no issue with oil level vs lean angle. If you don't have a center stand, that's your fault; the bike came with one!

What is the capacity of an empty '74 oil tank; 3 quarts? Is that level what the H mark represents?
How much oil do you guys add after an oil change? I recall that 2-1/2 quarts is just about right.