Jump to content
Sign in to follow this  

Water in engine oil

Recommended Posts

I was riding my '99 YZF400 in a very wet location a couple of weekends ago and stuck it in a hole up to the lower section of the engine. The motor immediately died. We got the bike out and I was able to start it back up after about 10 minutes of kicking. Bike thereafter ran fine the rest of the day.

I got home that evening and cleaned the bike up. Checked the oil and it was milky. I flushed it with some regular oil and continued to do so for another 4 flushes until it came clean. At that time I went back with a new filter and Motorex. Air filter was slightly dirty but did not appear to be wet. I service air filter after most every ride.

I have had this happen once previously and cannot figure out how the water is getting in the engine. Keep me straight here. My theory is that it is not going thru the breather as it would have to get past the rings. Could it be going thru the crankcase ventilation tube? If so, is there an alternative routing for the tube?

Can anyone help me out here? I want to avoid this happening in the future.

Thanks,

Brian

Share this post


Link to post
Share on other sites

Yep your crankcase hose sucked up the water - never stop in a water/mud hole up to the bottom frame rails - you can reroute hose to the airfilter boot or cavity. I would change oil immediately and it may take up to 3 oil changes to get all water as well as sand etc.. out - change oil filters. I had this same thing happen on my WR several years ago.

Share this post


Link to post
Share on other sites

OK, thanks for the information.

Did you drill into the side of the breather housing and route the hose thru the hole and apply silicone or a sealer? Or would a better way be to simply route on the outside of the housing alongside the drain tube?

Thanks!

Share this post


Link to post
Share on other sites

An even simpler solution is to take a sharp blade, like an X-Acto, and cut a short slit in the backside of the breather hose at about the level of the cam cover/head joint. Cut the slit at a 30-45 degree angle, and no more than 3/8" long. This will allow the hose to function normally in most cases, but when it tries to raise a column of water up to the head, the vacuum will pull air through the slit instead.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

  • Similar Content

    • By BDTRENT
      Selling an FMF Power Core 4 exhaust system off my 450FX. Exhaust has 80 hours and is 100% functional. This will also fit the 14-15 YZ450F and 16-18 Wr450F. If needed I can also include new muffler packing although it does not need it. 
    • By Woody Oakson
      I have a 2008 YZ450F with a stock header pipe and Pro Circuit T-4 Slip-On Exhaust. I'm 99% sure the slip on is shot because its loud as hell and when I take it off and shake it it rattles. I would repack it but the screws are all stripped ect.
      Anyways I've gone over the carb multiple times and I've got it running pretty well. The only issue I have with the bike is that it sputters and pops around 1/2 throttle when I hold it there. When I give it full throttle from any RPM it runs great or when I give it about 3/4 throttle it spins up like a top to redline.
      Initially the popping and sputtering was way worse I made the situation better by moving the pilot jet up in a few sizes from a 45 (stock) to a 62. The issue has gotten way better since then but I'm not super sure what to do from here. Should I keep moving my pilot jet up in size because that's a pretty large jump right? I tried changing my needle clip position but that didn't help much if anything it just made starting it worse and little to no impact on the ride.
      Any input on this would be helpful. I don't want to buy other slip on. Also as for the rest of the carb I'm very sure everything else in it is what it needs to be at. I've replaced all the gaskets and O-rings cleaned all the jets, valve holes ect. fixed the accelerator pump timing. I just thinks its strange that my pilot jet size is going so far from the stock 45, but all symptoms point to the bike running lean.
    • By Haydenbaha
      Hi I was wondering if y’all have been using a 450 on your YZ250F?
    • By RockerYZWR
      Excel Takasago 17x3 front and 17x5 rear supermoto wheels with Metzler M3 tires in very lightly used condition. Less than 200 miles total on the setup. Warp 9 spokes. Rear has a Talon hub with 45T Sunstar steel sprocket and OEM rear disc, and front has a polished OEM Yamaha WR450F hub (for the stock speedometer), with a Motomaster 320mm disc. Included is a DID gold o-ring chain, 14T front sprocket, and front brake caliper adapter for a truly turn key setup. Everything is in excellent condition, not a single scratch on these wheels. Came off my '11 WR450F, but will fit many different Yamahas with 20mm front and 22mm rear axles. Asking $1400 plus shipping.
      **Will be driving up near Atlanta, then to northern Louisiana, OKC, and down through Dallas and Houston, TX soon -- can meet or deliver if in the area (Aug 31-Sep 9)**
    • By YZ426fNC
      Hi I’m new on the forum and I was wondering if a 2001 Yamaha YZ426f clutch is interchangeable with a 2002 Yamaha YZ426f clutch thanks , Coleman
×