Oil dripping? Problem solved check this out.

I had posted a thread a while ago about the constant oil dripping from the crankcase breather tube located on the left side of the bike that runs down to the skid plate :cool: . You cant miss it. It's the one causing all the mess on the left side of your bike. :thumbsup: I ride my bike on alot of dualsport trips and high rpms on the quite often :eek: . I was having to add oil every 50 to 75 miles and I was getting tired of it. This is what I did :p ... I removed the tank, found the top of this tube (the largest tube that connects to the center of the valve cover). Removed the tube and went to the Yamaha dealer and purchased for $5.00 a small waterproof crankcase breather. I also purchased 2 feet of 1/2in. tubing for $1.00. I attached the breather to the new tube with the supplied hose clamp in the breather package. I mounted the breather next to the dip stick neck(see picture) and routed the other end down along the frame to the top of the valve cover and applied the stock clamp. (As long as the tube is 10+ inches long and it's mounted at least 8 inches above the valve cover it will work properly). I rode for approx. 150 miles last weekend and the oil level has not dropped at all nor has the mess returned on the left side of the bike :thumbsup: . This mod allows the oil to flow up the tube slightly but not far enough to puke out the top enturn letting it slowly drain itself back down the tube again. Did I mention that this will also make the crankcase water tight :bonk: ... If you stall in a huge puddle, rest assured with this mod your crankcase wont be full of water ending your day :worthy: ... Hope this helps and I really think that this should be one of the essential mods done on all wr and yz's. One of the best valued mods seeing it was only $6.00 total. Anyway im done now enjoy and please leave feedback...


what happens when it rains?

thanks :thumbsup:

Dunno, but he said it was a "waterproof crankcase breather"

Its a waterproof filter, thats the key. The better question is if you stall in a puddle with the stock configuaration, will you get it started in time for the water to go up the tube into your crankcase??? Ive riden in pooring rain, snow and just about anything mothernature has to offer and no problems!!! :thumbsup:

Looks like an interesting alternative - I've yet to reroute mine to the airbox as everyone else does because I don't like the idea of the breather blowing spooge in there. Can the crankcase breather survive an inadvertent squirt from the old garden hose? Could water work it's way back to the head? If not, I like the idea........... :thumbsup:

a 1000 miles of hard riding on my WR450 and hasn't dripped one drop of oil

a 1000 miles of hard riding on my WR450 and hasn't dripped one drop of oil

6000kms ? miles on mine and no oil problems/dripping.

I would not recommend any flow resistor in the cam cover breather air flow.

That is a good way to damage and blow some engine seals. :thumbsup:

That looks like a crankcase breather and it would be fine for that purpose.

The problem seems to be fixed in the newer bikes but mines a 99 400 and so is two of my buds and they all have the same problem. This fixed it for us. Just thought id pass the news on but beware, you have to mount it up and out of weathers general direction and it must be waterproof material, they make some with chrome plated covers for wether deversion. I put a plastic bag over it when i wash the bike just in case... P.S. i didnt like the idea of oily airboxes either thats why I came up with it and it works!!!!!!!!

Not a good idea and looks ugly , why not route a tube to the air box and install and automotive PVC valve

I thought we were supposed to run that hose into the air box to make the bike water proof?

If we are talking about the same hose, that is what I did and have no issues with leaking oil.

I think the better cure would be here to take a look over the piston and rings. Filling oil every 50-75 miles is very unusual.

Yeah. My bike has the breather tube drip (02 426), but I've never had to add oil between changes due to it, nor has it leaked enough to wet the entire left side of my bike. Just an annoying spot or two on the garage floor to clean. Adding oil ever 50 -75 miles sounds wierd.

If the breather works for you, though, good job.

Filling oil every 50-75 miles is very unusual.

i agree.

your problem is deeper then escaping oil vapors!!

i took my vent hose up the right side of the bike. now it vents between the air box and the RH cover. it doesn't drip at all. not even after 100s of long wheelies @ 10 000rpm. the vapor sticks to the plastic and then dust stick to it. not much all and all for how often i clean it.

I ride dual sport a lot at constant high rpms for very long times, so do my two other buddys that both have the exact same year bike 99 wr400. They all do the same thing. One engine is new, mines got 1200 miles or so and the other one has 5000 at least. Its just something the 99's do at those rpms for that lenth of time... Anyway thanks for the concern about something maybe being wrong.

P.S. your tube being ran into the airbox doesent make the crankcase air tight. Theres a drain tube in your airbox for a reason... Water gets in there... Not much but it does. I like the design above cause it not only is truly waterproof but it naturally routes the oil back where it belongs. Works for me. Different strokes right!!!

my engine has over 48 000km on it and it doesn't burn any oil............ but the 400 and 450 are quite a bit difrent.....

my engine has over 48 000km on it and it doesn't burn any oil............ but the 400 and 450 are quite a bit difrent.....

Simon, with your 48 000 km on the counter you are only confirming that these engines are almost unbreakable if you maintain it well. I've made about 10 000 km on my old '99 WR 400. I was driven it for 6 years and at each oil change I got this same oil volume drained out as filled in...and the most unbelivable is that I was using the original pistons and rings till I sold it :thumbsup:

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