Originally Posted By: Lawn_Care
Originally Posted By: Ducked
Also says
"Be sure not to use oils labeled “ENERGY
CONSERVING II” b or higher. Engine oil
also lubricates the clutch and additives
could cause clutch slippage."
Is that true for an automatic CVT scooter, or have they just cut and pasted that from a motorcycle manual?
Yup - CVT scooter is a whole different animal. Use any oil you'd like. I prefer an HDEO due to the high rpms they sustain, but to each his own. Any stout oil of an appropriate grade (as per manual) will be fine.
No need to buy bike-shop specialty oils for a scooter.
From checking a few more Yamaha manuals available online, this fundamentally half-assed procedure seems to be more or less standard for Yamaha scooters, without the clutch slip stuff, which I THINK is just wrong. For example, the YP400T manual has:-
"1. Stand the scooter on a level surface.
NOTE:
_
• Place the scooter on a suitable stand.
• Make sure the scooter is upright.
2. Start the engine, warm it up for several minutes, and then turn it off.
3. Check:
• engine oil level
Wipe the dipstick 1 clean, insert it into the oil filler hole (
without screwing it in), and
then remove it to check the oil level.
The engine oil level should be between the minimum level mark a and maximum level mark b.
Below the minimum level mark → Add the recommended engine oil to the proper level.
CAUTION:
_
Do not allow foreign materials to enter the
crankcase.
NOTE:
_
• API Service “SE”, “SF” and “SG” type or equivalent (e.g., “SF-SE”, “SF-SE-CC”, “SFSE- SD”)
• Before checking the engine oil level, wait a few minutes until the oil has settled.
4. Start the engine, warm it up for several minutes, and then turn it off.
5. Check the engine oil level again.
NOTE:
_
Before checking the engine oil level, wait a few minutes until the oil has settled."
I don't like this procedure because its more time consuming than checking cold, and its likely to be less consistent. Specifically
(a) You basically have to repeat the entire procedure twice ( 2=5, 3=6) , the second time (only, for no obvious reason) telling you to wait a few minutes before checking the oil level.
(b) There are many more uncontrolled variables with this procedure than there are just checking the oil-level cold. For example
1.How hot does it get?
2. How long EXACTLY do you let it settle? ("a few minutes" is imprecise)
3. How much does it settle? (this will be influenced by 1. 2. and the oil used)
4. How much does it cool while its settling? (too many influences to list)
The only reason I can think of that checking cold would produce the overfill I'm accused of is if oil expands significantly when hot.
According to this site:-
http://www.engineeringtoolbox.com/cubical-expansion-coefficients-d_1262.html
Volumetric Coefficient of Expansion of Oil (unused engine oil) is 0.00070
Assuming you put in a litre of oil at an ambient temperature of 30C, and assuming its at 80C when its level is measured, it'd have a volume of 1035 mls, or 35mls more. Maybe this is enough to produce an overfill.
If it is I suppose I could just put in 35 mls less when I check and fill it cold.