A friend has a '94 Beta and drained his gearbox oil and found it a coffee colour mess. There is no obvious sign of missing oil or water coming from the engine. How can we determine where the water is getting into the oil? I thought it maybe a water pump issue.

Thanks.

id say water pump too

I had the older Beta Zero that leaked the coolant through the seals on the water pump shaft.

If my foggy memory serves me, there were two small seals on the shaft that needed replacing.

thanks for the info, he does have a Yamaha WR400, so he is familiar with watercooled bikes, but this one had him stuffed. When my '03 Sherco's waterpump was failing, it dribbled coolant thru the small hole to let me know something was amiss there. The Beta has done none of this.

Is it the color of milk or coffee and how long since the last oil change?

A warm gearbox if cooled in a stream will contract and suck in air - or water if the breather happens to also be in the stream. Mine did once.

Change the oil out a couple of times with some cheep ATF and it may be fine.

Oh and a top tip is to run the breather tube up high..... !

I'd agree. It's worth a few changes of cheap oil first as you may be surprised. The old oil could have been in there for ages and even if not a load of short runs still create condensation in the gearbox which can turn the oil milky.

he showed me a pic of the oil, and it would have done the ice coffee manufactures proud! He's taking the bike back to the workshop where he bought it a few months ago for a full check over( waterpump reco, fork seals and tune up) this week. It could be just condensation as you have pointed out, but he would like it sorted before he rides it again. Ive had milky oil in my TY250a ages ago and once the engine warmed up it wasnt too bad after. I changed the oil completely the next week.