Oil in 250r radiator

[Ryah]

I just came back from Glamis and my radiator fluid was a little low. I stuck my finger in to check it and it came out covered in oil. where could it be entering the radiator system from? I know to check the waterpump, but could it be coming from anywhere else. This is the first engine I tore all the way down to the the trans by splitting the cases and putting in a new crank. I think I've done something incorrectly upon rebuilding it. Any ideas where all to check. I rode it all weekend without any problems, except at high speed flat out runs. It would cut out like it wasn't getting enough fuel, but ran great for any time that it wasn't run all out for an extended period of time (ie wide open for 15+ seconds in 6th gear). Any ideas would be greatly appreciated.

[Rennat_2006]

Must be the water pump seal but usually the gear/trans oil has the coolant mix in with it not the other way around. Check the trans oil and see what it looks like

[Chevy n Honda]

Head Gasket ?
Don't own an R but it's the first thing I check on anything else
that has oil in the coolant. Compression check should tell .

C N H

[Ryah]

Funny that you mention that. It did have a very minor head gasket leak. But do you think that the oil could have been premix?

[Ryah]

I drained all the bottom end oil. It was dark but I saw no traces of water in it. Could it really be the premix from a leaking head gasket builing up over time. It had about 9 hours of ride time on the top end. Would this be enought time for the oil to accumulate?

[Rennat_2006]

I doubt it would be from a head gasket. I've never heard/seen about fuel mixing with coolant, In cars you see oil just because the have oil passages by the coolant passages.