125-200cc CR 125 water in motor

I seem to be having an ongoing issue with water in the oil of my daughters bike. The vent hose seems very short ( about 6 inches ) so I rplaced that with a longer one. I'm pretty sure that it's not coolant as it's clear and we use motul coolant that is green. Has anyone else had this issue wit a CR 125 or a WR 125?

re-route the vent tube into the air box or high enough so it won't come into contact with the water.
when you travel through cold water it can create a vacuum in the crankcase due to cooling and suck in the water.

Don't rule out coolant just because it doesn't appear green in the crankcase. Once mixed in the oil the green tint will not be noticeable. How old is the bike? If it's very old the head "O" rings will flatten and let water pass especially during warm up. A leaky water pump seal is also possible.

This might be an un-popular reply but…I usually remove the vent hose altogether. That vent is packed away in under the reed case and sees very little water. Ever. My son has watered out his bikes a number of times, yet we have still never gotten water into the gear case.

Edit: One other thing, is the coolant level going down? Pretty well the only way for coolant to make it into the oil is through the water pump shaft seal or maybe the centre gasket. If you are constantly having to top up your rads, it may ineed be coolant.

bingo!

sidenote- dont route yer trans vent up- it cant drain off that way. esp after you wash yer bike. it's makes it a straight path to the trans.

if you suspect coolant in your trans, and the level of your radiators is not going down, your are probably experiencing condensation in your crankcase- due to a LOT of reasons. dont panic. just change the oil and monitor your coolant level. check the coolant cold before a ride. if your bike go hot during the test ride and pissed out coolant, which i doubt as these things cool like a champ, then the test is invaild. i live in a dry area and my oil is black with silver in it from abusing the clutch. the condensation that usually collects gets burned off in about oh, maybe 30 seconds into my ride....

do a test and let us know how it goes.

We haven't noticed it puking any coolant. The bike is an 08 with very little use on it as she just recovered from a knee injury. I put 15 psi on it for an hour the other day with a pressure tester. I had the entire clutch out of the bike at the time and didn't see a drop. The only real water it has seen is the odd puddle on a track and the pressure washer.

I've been chasing a water in my gear oil problem for about two years on my 06 gasser 300. If you want to rule out rad fluid send a sample out to an oil testing company. (about $25) Thats what I did ... no glycol. Keep in mind they test in Parts per million. The last sample I sent out had so much water in it they could not do a flash point test ... i.e. it would not burn ... it would just boil. that sample had about 15 hours on it in pretty dry conditions. No clue where the moisture is coming from. oil comes out looking a watery light gray. I've replaced just about every seal I can think of. Bike runs great and I'd like to sell it but .....

guys- as Bill stated, unless your coolant level drops significantly, the water is not leaking into the trans from the cooling system.

hot oil/cases collect condensation when it cools. it's evaps off during running then it re-condenses new moisture after shutting it off.

your area and other factors (even washing it) determine how much condensation collects.