Petrol/oil mixture

[Dogsbody]

Which synthetic? Some are designed for water cooled engines. I rang Silkolene technical to check their recommendation, and although told Pro KR2 @32:1, opted for 25:1 and have had no problems. Other Silverstone owners run 20:1 with R40 but it has too many disadvantages for me. Dogsbody

[John Wakefield]

this is great on my recently built scottish outfit i was reconmended to use 40.1 mix with sikolene synthetic oil , runs ok and seems fine in the sections , but seizing about four times when running in ,i thought was my fault , so kept stripping the top half filing off the high spots then running until all seemed well then on the beamish trial it only seized five times on the road between sections, the plug reading looks good and the power is all there, i now am thinking that maybe 40.1 on a hard ridden trials outfit is not enough ,has anybody got any other suggestions on what mix and oil i should use , i have only been riding bikes for45 years but this has me confused. will.

Villiers stipulate 20:1 for the 9E/32A engine. ie as stated in the post from Villiers forum "The older design of Villiers engines means they need a lot more oil. They are the last of the early design of two-stroke, for best results stick to 20:1."

[John Wakefield]

Filtrate Oil

Interesting to read this page that Brian has recently posted on the Manuals Thread.

Surprisingly Greeves recommended Filtrate Colloidal (graphited) Oil in trials & roadsters initially at 24:1 (running in) then 32:1. but Shell 2T at 16:1 & 20:1
Whatever happened to Filtrate? I used it back in the 60's but cant remember that it was any better than the normal 2 stroke oils (Shell, Castrol etc) It did make a mess if it leaked out of the filler cap, & coated the inside of the engine with black residue.

[Andy Z]

Just for a laugh, my 1920 Villiers 269cc engine runs a 12:1 petroil mixture, using straight 50 engine oil!
This is because of the plain main bearings and cast iron piston!


Seriously though, Greeves recommendations in petroil mxtures are a bit all-over-the-place. From 16:1 to 32:1 is a lot of difference on the same jetting. Was Filtrate that much better? It was still around in the 80s, but haven't seen any since.

[John Wakefield]

Just for a laugh, my 1920 Villiers 269cc engine runs a 12:1 petroil mixture, using straight 50 engine oil!
This is because of the plain main bearings and cast iron piston!


Seriously though, Greeves recommendations in petroil mxtures are a bit all-over-the-place. From 16:1 to 32:1 is a lot of difference on the same jetting. Was Filtrate that much better? It was still around in the 80s, but haven't seen any since.

Molyslip was another name from the passed, an additive for 4 strokes but think they did do one for 2 strokes.

[Dick F]

Petrol/oil mixture

John, that dam Filtrate got everywhere! not just in the engine i remember my Dad cursing me as i knocked a tin under the car and he reversed out across the concrete drive and was not amused! i think its best use was painting fences with

[gribley]

In the A. Bell book on 2 stroke tuning he states that 2 strokes will make more power with more oil (up to a point).
My Blue Meanie with a kart barrel and methanol smokes like a good 'un at 25:1 even when warm (it never gets hot, 1/4 mile at 11,500RPM and the barrel is just warm to the touch) but I am running methanol so it is going through a main jet in the 2.8MM-3.5mm range
I would personally err on the slightly oily side, but watch your jetting. the more oil you put through the less fuel there is so you run the danger of a lean mixture.
I use shellsport M

[46T Sprocket]

Interesting article, but it's nearly 30 years old.
Dogsbody

http://www.amazon.co.uk/High-performance-Two-stroke-Engine-Prof-Dixon/dp/1844250458

This book is more up to date 2005 - but it still gives similar information to what Jennings said in that old article and in his even older book all those years ago. There is much the same with the info on oil in the Bell book too.

If you want to delve further into this subject try Professor Gordon Blair, Of QUB fame's book. It's a good read.

http://www.amazon.co.uk/Design-Simulation-Two-Stroke-Engines-Gordon/dp/1560916850

[gribley]

£197 and £77.50, I would rather spend that on bike parts, tools and beer

[46T Sprocket]

£197 and £77.50, I would rather spend that on bike parts, tools and beer

Well don't drink when you get it fixed mate. I got my copies on ebay at a fraction of those silly Amazon prices.