i have a 1993 gas gas 250 contact rubio sig model. as my first trials bike , now i need to know a few stupet questions? does it run on unleaded or leaded? and how big is the tank? and can you buy workshop manuels for these bikes and where from? also it has rubio's signature on the side, is it a rubio signature model? thanks colly

leaded if you can get it or just unleaded i think your gas gas is supost to be run at 75:1 my mate has one and he asked bvm moto and that is what they said. dont no how big the tank is but a ruff guess would be around 3 litres. not sure if it is a rubio signiture model but im sure one of the other guys can tell you that.

happy trialing

Edited August 3, 200422 yr by beta boy

Try and use unleaded its better for your bike if you use leaded the bike will start pinking which is a pain so run the bike on unleaded. As for the manuel you can ask around companys like Haven Trialsport, BVM or White Brothers to get you a manuel.

Gavin

wonderboy you talk a load of b8ll8cks leaded fuel will do the opposite to what you say. unleaded also has a lower octain rating if you kow what that is

Well apart from the fact you can get leaded fuel any more looks like you

wonder boy is wrong again where i live premium unleaded is 95 octane ans super is 98 and leaded fule is still sold in some places but it is more expensive and the suply is limited

not worth arguing if the point is not understood

wonder boy is wrong again where i live premium unleaded is 95 octane ans super is 98 and leaded fule is still sold in some places but it is more expensive and the suply is limited

No I

well maybe where you live the fuel octanes are like that but here in jersey it is what i said and just to prove you wrong here is a site that shows you all the places in the uk that sells leaded petrol http://www.leadedpetrol.co.uk now your the one that is talkin b8ll8cks mate!!!

Getting back on subject a little the lead in our fuel was put there to help lubricate the top end of 4 stroke engines. The development of better materials and a wish to reduce harmfull emissions drove the change to unleaded. All engines will run on unleaded but for the older ones the top end will be lacking vital lubrication and will wear faster. If you have such and engine then it's obviously better to run leaded or lead replacement fuel.

A two stroke engine doesn't have valve gear to worry about and more importantly has oil mixed with the fuel so plenty of lubrication is provided. Therefore you can run a two stroke of either leaded or unleaded and will be fine.

I wouldn't recommend you change fuel ratings constantly as each one has a different octane or RON rating and will effect the carb set-up. If your bike is well setup for 93 octane keep running that likewise if you've setup for 98 octane leaded then stick with it. You probably wouldn't really be able to notice the difference and it will do no harm but it's best to stick to one octane rating and a constant fuel/oil ratio. Always use a good branded fully or semi sythetic two stroke oil and fix at around between 70 - 80:1.

thanks for the help. i run40:1 at the moment as that is the mixture i had for my yamamha ttr. but will run 75:1 later. i will post pics of my bike up soon'ish'