Hello all, New to both trials bikes and to the site.

Bought a Beta Techno 250cc (1994) bike a week ago as a problem runner. The previous owner stated that it wouldnt run properly and needed the carb setting up.

Being a home (diy) mechanic I have checked over the bike and found a few little niggles, the running problem seemed to be solved by filling up with fuel???(70:1 mix)

I have riden it around for about 2 hours and it pulls well, ticks over fine and I thought was ready for a trial.

So wrong .

Checked the coolant and there is now a fair amount of oil coming to the surface.....

Correct me if Im wrong but with a 2 stroke there isnt any direct contact with oil if a gasket fails, could the oil from the gearbox get near the coolant. I am hoping that some fool has filled the topped up the coolant with oil but before I start pulling it apart thought I would get some advice from the experts here

What oil would people recommend for the gearbox, I will change all fluids as often as possible.

Cheers for any comments.

Lee

Bodgit,

You have 2 sources for oil (assuming no nut put oil in your coolant as you mentioned). One is the gearbox, the other is the engine. Generally, the cooling system runs at enough pressure that coolant enters the gearbox and not vice-versa. My guess is that a head o-ring is allowing a small amount of cylinder charge to leak into the coolant passage. The problem with this theory is that this will over pressurize the coolant system and you will have overflow from the radiator cap.

As for oil, a lot of people ran Dexron atf in their Techno gearbox. I used to have a '96 Techno and tried atf, but had better results from the Elf gear lube. I now use Maxima 75W gear lube in my Rev3 and I find that engagement is smoother with it than with atf. If you really want to pin down the oil source, you could fill the trans with Dexron and change your coolant. If the oil getting in the coolant has a red tint, then you have found the source. But my bet is it will not be. Please let us know what you find.

Sometimes the oil in water can be the seal on the waterpump shaft failing.Does the bike overheat and lose water through the radiator cap or overflow pipe?If not I would be looking in the waterpump area.If you're really unlucky it could be the casing eaten away by previos owners not using enough antifeeze in the water,good luck

I will go for, best bet water pump impeller shaft............. worst case scenario, hideous porous corroded cases.

best to check by removing the whole clutch casing.

good luck.