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oil change

Posted: Wed Sep 18, 2024 4:03 pm
by George
Following a suggestion on a previous post, on my last oil change on the 350 Road I changed from the expensive Silkolene Comp 4 20-50 4T semi synthetic to Millers Classic 4T 20-50 mineral oil. As I ride two Ducati bevel singles regular this saves a lot of expense.
I now find that after a ride when starting after a tea break etc I first have to free the clutch plates to avoid stalling. With yet another oil change almost due my question is:
Is this just a coincidence or could the Millers oil cause the problem.
Sorry for another oil question but it does have a different slant to the usual questions.

Re: oil change

Posted: Wed Sep 18, 2024 7:14 pm
by ranton_rambler
I use the Silkolene. Even expensive oil is nothing compared to the cost of fuel if you do any decent mileage.

Re: oil change

Posted: Wed Sep 18, 2024 7:52 pm
by Bevel bob
It may be that the new oil is just thicker than the old used oil.

Re: oil change

Posted: Wed Sep 18, 2024 8:52 pm
by themoudie
Aye George,

In my experience "freeing off the plates", with the 450, is part of the first start up routine of the day. Not that they are always stuck. However, I then know that I am going to have a smooth take off.

Having used 20W/50 Duckhams Q multigrade, 40W mineral oil, Millers and Castrol, 10W40 Westlake semi-synthetic and now Smith and Allan 15W/50 synthetic, over the past 48 years, the clutch has always tended to "stick" if left for a week or so. 450 spring pressure and the viscosity of the oil probably all contribute to the "stiction"!

As for "expensive" oil? As we have often said before on this forum, nothing wrong with a 4T 20-50 mineral oil, providing you change it regularly, between the 1,000 and 1,200 mile marks, or after every race meeting. I prefer the extra lubricity of semi-synthetic, synthetic oils and change the oil between 1,200 and 1,500 miles. So, 3 to 4 oil changes a year, 2.4 litres (4.25 pints) a time. A 20 litre drum lasts 2years and costs ~£81-65 at today's prices. The synthetics also adhere well to all the internal engine surfaces, if you only run the engine intermittently, this helps prevent corrosion.

Having broken a clutch post at over 60mph, fired the bits through the clutch cover and ridden a further mile, with oil all over the rear of the bike and my left leg, before trying to change down to turn right and finding it a bit difficult to free the clutch, I can testify to the lubricity of synthetic oils! :roll:

Good health, Bill

Re: oil change

Posted: Wed Sep 18, 2024 9:37 pm
by George
themoudie wrote:Aye George,

In my experience "freeing off the plates", with the 450, is part of the first start up routine of the day. Not that they are always stuck. However, I then know that I am going to have a smooth take off.

Having used 20W/50 Duckhams Q multigrade, 40W mineral oil, Millers and Castrol, 10W40 Westlake semi-synthetic and now Smith and Allan 15W/50 synthetic, over the past 48 years, the clutch has always tended to "stick" if left for a week or so. 450 spring pressure and the viscosity of the oil probably all contribute to the "stiction"!

As for "expensive" oil? As we have often said before on this forum, nothing wrong with a 4T 20-50 mineral oil, providing you change it regularly, between the 1,000 and 1,200 mile marks, or after every race meeting. I prefer the extra lubricity of semi-synthetic, synthetic oils and change the oil between 1,200 and 1,500 miles. So, 3 to 4 oil changes a year, 2.4 litres (4.25 pints) a time. A 20 litre drum lasts 2years and costs ~£81-65 at today's prices. The synthetics also adhere well to all the internal engine surfaces, if you only run the engine intermittently, this helps prevent corrosion.

Having broken a clutch post at over 60mph, fired the bits through the clutch cover and ridden a further mile, with oil all over the rear of the bike and my left leg, before trying to change down to turn right and finding it a bit difficult to free the clutch, I can testify to the lubricity of synthetic oils! :roll:

Good health, Bill


Thanks for the comprehensive answer Bill. Of course I am comparing the 350 with the 200 Elite, that does not stick, without thinking about spring pressure. The plus point, and I am not sure if it is the mineral oil or because engine has now covered 2000 miles and settled in but the gear changing feels much slicker on the 350, something I never expected on a bevel single.Having done a little research I will stick with mineral 20-50 oil but try Morris Golden Film that seems to have good reviews. Price set between the other two. Available in 5ltr which should give two oil changes.