1.5% two-stroke mix for 2009 250 Beta

[McTrucky]

That is what the manual says, 1.5% which I think is about 66 to1.  

 

That seems awfully thin to me.  On my previous 2 strokes (MX race bikes) around 40 to 1 was what I ran.  The oil I have left from those days (Silkolene and Putoline) both have mix guides which stop at 50 to 1, so diluting them further seems risky.

 

So, is my old oil (guessing about fifteen years old) better thrown away and replaced with something newer? 

Does a lower reving trials bike want thinner mixtures than a race engine?

Are there special 2t oils designed for trials type riding that would be better than my race oils?

Should I uuse my old oil, but at 50 to 1?

Am I over thinking, and should just use my old oil and mix it to 66 to 1?

Thanks all.

 

[compactpete]

Dump the old oil and use a proper trials specific oil such as Rock or Putoline Strawberry.

You can safely run 70ml to five litres in a Beta, some people run less. I run 50ml to five litres in all my modern bikes, and 30ml to five litres in Vertigos.

 

 

Edited December 5, 2022 by compactpete

[McTrucky]

4 hours ago, compactpete said:

Dump the old oil and use a proper trials specific oil such as Rock or Putoline Strawberry.

You can safely run 70ml to five litres in a Beta, some people run less. I run 50ml to five litres in all my modern bikes, and 30ml to five litres in Vertigos.

 

 

I realised after spending over £100 on putting diesel in my car, and some V-Power petrol in a can to mix up for the Beta that penny pinching by using the old questionable oil vs buying a litre of new "Trials" oil was rather stupid.....  and I guess one 1l bottle at £16 will probably be less than half used by the time I sell the bike.

 

So thanks for the clear advice.

Edited December 5, 2022 by McTrucky

[faussy]

With a semi synthetic trials oil 66:1 is fine. With a fully synthetic mx oil you could probably run a little leaner. But IMO its not worth it. An old bike will not run any better running less oil, for you just to save a couple quid. 66:1 on your mx oil is more than adequate, and if it runs rich its probably more due to the mixture too rich or a clogging exhaust on a 2009 bike

Edited December 8, 2022 by faussy

[McTrucky]

Thanks.  I now have a strawberry flavour bottle of Putoline on order, and will go with around 66 to 1. 

Might try mixing it with milk and serving with IceCream, but reckon that will need to be a bit heavier mix.

[tshock250]

Always ran betas on 80:1 with a good quality synthetic oil. Thats plenty for trials use, you'll still get oil build up at that amount as you'll find out at the first big hill climb.

[lineaway]

As long as you ride it like a trials bike you can easily run 100:1, but 80 is just safer and 66 is just so wrong.

 Yeah, you should not be racing.

[carl ekblom]

I have used 1,5% for decades and have tested 1%. No ill effects as far as I can see. Remember chain saws use 2% and they stay at high rpm for very long periods. Use good modern synth oil.

Edited December 10, 2022 by carl ekblom

[dan williams]

On a MX bike you are blowing a lot of oil out the exhaust. On a trials bike the engine speed is so low that a higher ratio will just pool in the crankcase and gum up the exhaust. Most run their bikes around 80:1 but 100:1 is not unheard of especially if you’re a plonker. For reference the Vertigo with fuel injection runs at 200:1. Modern engines with water cooling and electrofusion cylinders don’t have the same thermal stresses as the old iron bore air cooled engines. Even at the higher oil ratios I haven’t seen an oil related failure in a modern engine.