Hi there , im new to the sport and just bought myself a 2001 beta rev 3 bike ,,the owners manual says oil to be mixed 3.5%mineral 1.5% synthetic , can anyone tell me if this ratio is correct , as it equates to 40:1 ?

im realy enjoying the steep learning curve but the last thing i want to do is screw up with a wrong mix

spot on. use a good quality fully synthetic oil and the highest octane pump fuel mixed at 1.5%.

spot on. use a good quality fully synthetic oil and the highest octane pump fuel mixed at 1.5%.

So what is the actual ratio in total of oil to petrol ?

75cc oil to 5lt of fuel. about 66 to 1

Edited September 14, 200718 yr by paul w

Not sure where you get 40:1 from? And I think it might be me just not understanding what you're saying (or what the manual is saying.

Are they saying if you use mineral oil you need to use it at 3.5% (approx 30:1)

And if you use synthetic oil, use it at 1.5% (approx 66:1)

I'm not sure of the specifics with Beta, but I would say you can't go far wrong with synthetic mixed at around 66:1.

My preference is nearer 75:1 or even 80:1 on the Sherco.

Edited September 14, 200718 yr by bikespace

I've always used 80mls of synthetic oil to 5 litres of fuel which gives 62:1

I run my beta at 75:1 (1.5%) - which is approx 67ml fully synth per 5L petrol - seems fine at that.

Jim

Course the above is complete rubbish isn't it - 1.5% doesn't equal 75:1 but if you're going to be pedantic you need to allow for the volume of oil so you'd put 75ml oil in 4925ml petrol - or 76.5ml in 5L - or as I generally spill some and leave some in the measuring jug just forget it .........

Edited September 14, 200718 yr by jimw

I dont understand why this issue is so difficult that you need to think of ratios etc? Its quite simple. Buy a 10 litre canister. Use high quality fully syntetic oil like Castrol TTS. Pour 1.5dl oil to canister and then fill it with 10 litres of 99+ gasoline. If you have the possibility, you can use also racing fuels that are like 102+ octanes. With this oil mixture you are safe and the bike dont smoke that much. However, just a hint. After driving few hours, "clean" the engine and exhaust every time after practising by driving with 6th gear 1-2 minutes with full throttle if possible. Leave the bike running for 3-5 minutes. You will see that it is smoking like hell which means that its burning carbon deposit and you will notice that next time your bike is revving clearly and you enjoy driving more.

This hint is just because, when you use too fat mixture, low quality oil or 95 octane gasoline, your bike is soon absolutely blocked-up. Therefore I really suggest that invest more money and use high quality oil and gasoline. In the end you will end up saving not only money put servicing as well!

I dont understand why this issue is so difficult that you need to think of ratios etc? Its quite simple.

If you're OK at maths it's quite simple with ratios.

I've seen lads on the way to trials who've got a litre or two left in their can, and want to fill it up. But because they can't do a bit of simple arithmetic, they're screwed.

I know if I can only fit eight litres in my tin and I want around a 70:1 mix, then I have to divide 8 litres by 70 and thats the oil I need, so I'd go for about 115ml.

Even more simply, I know I can just fill my can right up without worrying, and just divide however much the pump says by 70.

Just get a ratio rite and you'll be all set for mixing your gas. I have been mixing my Beta at 70:1, 50% Pump gas and 50% Race gas.

http://www.motoworldracing.com/Ratio-Rite.html