Oil tank dipstick set difference

Two different types of dipsticks for the later Commando oil tank were used. The only difference is the H-level mark. The dipstick with the lower H-level mark is the correct one (2,8 liter) therefor the dipstick with the higher H-level mark will allow you to slightly overfill the oil tank. Not a fatal problem but you can easily make an other mark like the correct level dipstick if necessary :idea:
I suspect the higher H-level dipstick was used in the early Commando without the extern oil filter system however I have seen both dipsticks in early and later Commando's.

What is a "later" commando?
The commando series has 3 different tanks types, though there are some sub variants.
fastback, S (central), roadster
They all accept the same dipstick...markings aside.
I agree establishing a proper oil level is worth while.

dynodave said:

What is a "later" commando?
The commando series has 3 different tanks types, though there are some sub variants.
fastback, S (central), roadster
They all accept the same dipstick...markings aside.
I agree establishing a proper oil level is worth while.

Click to expand...

By "later" I mean all Commando's with short triangular oil tank like the last MK3 (I know pipe sizes can differ). So to your specs it is the Roadster type.

I measured the capacity of this oil tank and marked the levels at 1 and 2 quarts.
Oil in the crankcase sump is extra.

My 71 750 has the lower dipstick shown above and my 74 850 has the upper one with the lower h mark.
on the last big 3145 mile trip my 850 used 1 1/2 litres of oil during the first 2600 miles and nothing on the last 550 odd miles. I always topped up to the H mark at the end of every day. On the previous long trip of 1250 miles I forgot to regularly check the level and had to add a litre when 100 miles from home. This seems to suggest to me that riding conditions rather than oil level determine how much oil the engine will use. As a result, I will keep the oil level topped up to the H mark when necessary.
Dereck

When my 74 Norton was in Commando form I found that if you filled the oil tank topped to the high mark it used oil, so every week checking the oil level it was down to the half way mark and always topped it up, but one day I decided to leave it at the half way mark and found it never used any oil at all at that level, so I think the high level mark was to high as all oil tanks need that air space, the Norton wasn't burning any oil, over fill the tank and it goes out the overflow pipe.
I run a 3 ltr round oil tank on my 850 Featherbed, 2 ltrs oil and 1 ltr air space, I also run a oil cooler all year round, my Norton never uses oil between oil changes and the same when in Commando form when I kept the oil level in between the low and high mark, so if you are topping up your oil tank regularly maybe you are over filling it, so leave your level between the low and high mark and see what happens if it loses any more oil.
I told my mate this when he told me he was topping his oil tank up weekly, since he kept his oil tank between the levels he hasn't topped it up since.
I have owned my Norton since new (41 years now) have rebuilt a few Commandos for mates and a have always told them to keep the level in the oil tank inbetween the levels and so far none of them have used oil between oil changes.

Ashley