Quick question, are 2 stroke trials bikes generally pre-mixed fuel? Or do they have a seperate oil pump ala road going 2 stroke bike engines?

Cheers

Si

Q1 yes

Q2 no

There probably are some older trials bikes that originaly had a seperate oil tank for the two stroke oil, how about the TY80?

I can't think of ever seeing a modern trials bike that wasn't pre-mix.

Yep TY175 had an oil tank as original too.

think all the TY range 80, 125, 175 and 250 came out of the factory with oil pumps and tanks but that was the first thing to be removed by a trials rider

Thanks for the info. Is it a bit of a job the pre-mixing? Or is there a standard set of equipment/measuring vials/shortcuts that everybody uses? I mix about a litre at a time now and again for the strimmer & leaf blower but it's always a bit of a mission trying to work out how 40:1 into a 1 litre container works then measuring the required oil etc, just tend to guesstimate and suffer the resultant smoke. What's the standard drill on mixing for trials bikes? Gallon at a time or do a batch the night before an outing? (I'm used to pulling in to the petrol station, filling up and riding off... spoilt )

Print this off, always useful... Work to litres not US gallons.

http://www.rctek.com/pdf/fuel_to_oil_ratio_chart.pdf

Put 75ml of two stroke oil into a 5 litre can and fill with high octane petrol. Thats what I run mine at and most of my mates do the same, and we've never had any problems.

2 STROKE CHART

This one goes up to the sort of ratios trials bikes use.

Edited October 1, 201015 yr by t-shock 250

It is not much of a hassle - once you buy some form of measuring device. I have a Ratio Rite cup that can measure the amount of oil needed for various sizes of fuel containers. You have not stated what type of bike you are riding.....but if you have a modern trials bike it will probably run at a much different ratio than your string trimmer. Be very careful to keep you mixed fuel in a container that you will not confuse with the unmixed fuel!

I use a hypodermic syringe (50ml) to measure, it's the most accurate way and you get all the oil out of it unlike a jug where some always sticks. Don't rely on the measurements on the bottle. I checked the quantity using an Ipone bottle (the one where you squeeze some up in to a small chamber)and it was 10ml out which is quite a lot if you are only putting 70ml in to 5l of petrol. Larger syringes can be found - try a vet?

Excellent tips & charts, thanks for those. Never thought of the syringe method, sounds relatively pain free, think that's the route I'll go, great tip Don't have a proper trials bike yet but gradually getting the picture (ie didn't know about the pre-mix!) Another thing, looking at various pics, is that the gear lever seems way forward from the left footrest & unreachable, how do you go through the gears seamlessly?

I've got a Beta ALP at the moment, sort of trail/trial bike combo, but want to try a pukka trials bike at some point.

Riders just tend to lift their foot off the footrest to change gear. I often ride a whole trial and only use 1st gear on the sections, it's quite rare for me to change gear in a section. The only time I tend to change gear if there's a very tight technical part followed by a big climb.