Thunderace oil thicknesses?

[Wideboy]

I've got three different oil types said for the thunderace

10w30, 10w40 and 20w40 all semi synthetic

if im burning oil i would want to use the thicker oil which is 20w40 (i think) but do the oil codes mean that the oil is at different viscosities when at temperature?

[Specialone]

It used to be how long it took to drain through a measured container, obviously the thinner, the quicker.

[Cymraeg_Atodeg]

This was explained in MCN a few weeks ago.

All modern oils are a combination of different oil types. The first number followed by the "W" is the "Winter" (or cold) viscosity, so, when the bike is cold the oil will have the viacosity of 10 weight oil, but it is 10W40 for example the oil will flow like 40 weight oil when hot, the higher the numbers of either means greater viscosity (thicker) oil.

The reason for the mixed oil types is because a 10 weight oil wouldn't be able to help the engine much when hot and a 40 weight oil would be like treacle on start up, so, mixed oil is the best of both :-)

[Wideboy]

This was explained in MCN a few weeks ago.


i read no further than this bit ;) :lol:

[Cymraeg_Atodeg]

i read no further than this bit ;) :lol:

You tool

[timwilky]

We do have oil experts on here, But I have not seen well oiled post for some while.

Viscosity is a funny thing, it is a measure of the shear forces required to allow movement of the fluid.

The method we used was to time the decent of a ball within a measuring tube. and I seem to recall the unit of measurement was the stoke or centistoke

[Bibio]

if its burning a lot of oil there is something not quite right.

stem seals, worn bore, sticky rings. give it a good flush out with engine oil flush and take it from there. there are also additives you can use to lessen the effect.

[suzukigt380paul]

i think you'll find that the thunderace and the earlier xups are well known for useing oil,(from new)and if you use a oil flush when you change the oil it will most likely make it smoke like a twostroke.so i'm guessing if its useing less than a 1 ml a mile then its not worth worrying about(1litre per 1000 miles)and 2ml a mile is getting a bit smokey,but if its burning 3 or 4 ml a mile then a strip may be on the cards

[Wideboy]

no work is necessary, there's loads of theory's flying about such as the bore wasnt machined perfectly circular ect

[Davies]

Over on the Thunderace forum they discuss using mineral oil if it's burning a bit. Food for thought :D

I used bog standard semi synthetic Rock Oil guardian (10w40) and it was fine :thumbsup:

[Wideboy]

Which is the correct forum? as i've found 3

[Lozzo]

I always used 10W40 semi-synth Motul in mine and it never did any harm. The previous owner had it from new and did 40K miles using the same oil as I did, all that ever failed on that bike was the bolt fell out of the gearchange clamp and it was stuck in fourth gear. He rode it half way across France 2-up and into Switzerland before it got fixed. I sold it with over 60K miles on the clock and it was burning 1 litre of oil every 2000 miles by then. It's now got well over 130K miles on the clock and does a regular Germany to Scotland run with its soldier owner - apparently oil consumption hasn't changed much.

All Thunderaces use a little oil between changes, it's just one of those things. Oil consumption gets a bit worse as they get over 40K miles. Just remember the oil light is an oil level light, not oil pressure.