Jump to content
Sign in to follow this  

Yamaha oil in breather pipe yfz450

Recommended Posts

Just bought 05 yfz 450,rage built national motor,480 athena kit ,wr crank.Can anyone tell me why we would have oil coming up breather tube that goes into air box?Also has a kn air filter with 2 sponge filters overtop.Too many?Any way to distinguish if indeed it has an athena kit by looking at the outside?

thanx for any help in advance

Peter

Share this post


Link to post
Share on other sites

thanx for replying.This started suddenly after riding in wet ,muddy conditions.Researched the subject and sounds quite common,but seems excessive in our case.Rode for 1/hr last nite and swingarm has fair bit of oil on it.Enough to drip off onto the ground.Anyone experience this?Appreciate any input on the subject

Peter

Share this post


Link to post
Share on other sites

exact came thing is happening to me, it starteed after the first time I cleaned the K&N filter. I mean there is a lot of oil on the swingarm.

Share this post


Link to post
Share on other sites

Sounds like this is a common thing .Doesn't seem normal to me.Does anyone know if there is a fix.Is the motor tired?We had a fair bit of oil on the arm also.Not sure on the air filter issue,seems like overkill.I was wrong when i said it was a k&n.After pulling off the first foam filter the inside says pro flo or something like that.It has its own foam built in.Do I need the second one?

Thanx for any help

Peter

Share this post


Link to post
Share on other sites
thanx for replying.This started suddenly after riding in wet ,muddy conditions.Researched the subject and sounds quite common,but seems excessive in our case.

The YFZ450 holds 1.98 quarts of oil... and accepts less than that when doing an oil change. There's a good chance you overfilled it. I always follow the manufacturers directions on adding oil to the crankcase and the resevoir and have never had a problem.

Share this post


Link to post
Share on other sites

That was the first thing I checked because I have had this with a ktm product that suggested 3/4 liter when changing oil but would spew out of the breather if you used that much .Less oil no problem.I did check ours and was right on the full line.Haven't changed it yet.Was wondering if I had another ktm on my hands.It's also been suggested to me that the motor is pooched and this is blowby.Seems like a lotta blowby to come on suddenly, and I don't have anything coming out the pipe or driveability issues.Pulls like a bear.That's why I'm using this site .Let the more experienced guide me.

Thanx for the input.Wanna go racin this weekend and don't know if we have a problem or not.

Peter

Share this post


Link to post
Share on other sites

I assumed this was a fresh motor since you just bought it. Sounds like you got a beat motor. If the oil in the crankcase smells like fuel, that's your second clue there might be blow-by.

Share this post


Link to post
Share on other sites

No, the oil is clean and does not smell like fuel.This happened suddenly,only noticed it after the really wet ride,but not before.Don't think we pulled in any water but it was my son riding it not me.airbox is open and has 2 large openings at the bottom also(?)Thinking it might be time to open it up.Motor was not fresh but was said to have maybe 20 hrs.Never know when buying used.Everyone but a few is of the opinion this is normal?I'm not so sure

Peter

Share this post


Link to post
Share on other sites
Everyone but a few is of the opinion this is normal?I'm not so sure

Peter

Maybe it's common if you overfill it? I'm riding with a few YFZ450ies this weekend. I highly doubt any of them will demonstrate that problem.

Share this post


Link to post
Share on other sites

Well I'm guessing by your last post that we have a problem then.Changed the oil and filled to 1.98 litres and we ended up being overfull after warming up.Installed longer tube from seperator and didn't have any leakage.Tough to decide if we should have to tear into the motor.That kind of crankcase presuure would indicate perhaps a cracked piston or poss h/gasket leak but we don't show signs of your normal worn out eng symptoms.

Thanx for your help

Peter

Share this post


Link to post
Share on other sites

I found this on the Duncan Racing web site - for modded yfz motors.

OIL BREATHER: It is also advisable to re-route the exit breather line going from the oil breather catch tank

(mounted LH side of sub-frame), it is no longer advisable to have it vent into air box.

It is NOT recommended to remove this breather catch tank.

It is recommended to install a longer hose on the OUT line of the catch tank and route it over top of engine

but below fuel tank to front of engine and have it stop in front of radiator. It is also advisable to install a

universal type paper filter on end of this vent hose. These types of filters are commonly used on 4-stroke

engines of all types.

Make sure that ALL of the engines breather hose lines are free of kinks or any other types of obstructions.

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 Big64N
      Good condition with a long list of high end upgrade parts.
      Rekluse EXP 3.0 with cover and slave
      EVO- Ellensburg suspension tuning for 6' 200# expert rider
      Fork bleeders
      Trail-tech map switch
      Moose 1-1/8 flex bar
      CYCRA probend bar guards
      SXS skid plate with linkage plate
      Clutch and water pump guards
      Frame guards
      Fastway Evolution III pegs
      SRT Pro Armor radiator and rear rotor guards
      Acerbic Front rotor guard
      TM designs chain guides
      DID race chain
      Renthal sprockets
      Gripper seat
      FMF F-bomb header
      Dirt Tricks timing chain tensioner
      Pro Wheel, wheels
      Tubliss front and rear
      New top end and valve adjustment 60 hours old
      Many more aftermarket parts as well as spare parts and service manuals included in the sale.  Willing to include 4 sets of tires with 80% tread left for full price.
      Great bike with plenty of life left and set up for anything from single track woods to wide open dessert.
      Can hang with any of the 450's but is much easier to handle in the tight woods.
      Priced to sell at $6000.00 
      Willing to consider reasonable offers but no trades or carry.
    • By dank08
      I am selling my 2001 yz426f(As is), I bought it used from private seller back in 2011.  I rarely used it at first, playing around in dirt areas and local OHV trails.  I began using it for bigger trail rides like Gorman in Hungry valley.  I hated the manual decompression. In 2015 I bought Hotcams stage 1 intake and exhaust cams for the auto decompression.  I had Motorcycle Tech in Upland, CA do the install.  They also installed a new Piston Ring and Intake valve.  Have work order paperwork and old parts from the job.  Last big ride was 2017 September, Kennedy Meadows.  Put on new tires before this ride along with fresh oil/filter and new air filter.  Bike ran like a champ and we made it up some some pretty nasty climbs first try 
      The Hand Grips are new. The front and rear fenders along with radiator shrouds are a year old.  Side # plate cracked as seen in picture.
      Still an awesome ol' powerful bike.
      Negatives are a heavy clutch pull and a grabby clutch.
      Selling because I've replaced it and have no intention of using it anymore.
      Pink in hand.
      I'm asking $1,500 OBO for the bike as is.
      No trades.
      Cash only please.
      Serious inquiries only.
      Thank you.
       
    • 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 YamahaYz1
      Hey TT, I know there's endless topics on YZ250/ two stroke tuning in general but I have not been able to find one that helps me get my 09 YZ250 set up for my riding style and where I ride so I'm here asking for help. I got this bike around 1.5 years ago and have not known how to set it up properly. I know no one can give me a perfect set up but I'd like a good starting setup to work from and tweak to perfection. Throughout this time I've had this bike, its always been covering the bottom of the entire silencer and dripping all over the swing arm and rims with oil. Also, the joint between silencer and expansion pipe has oil around it too but I've heard I have to close the gap a little to squeeze the silencer a little tighter and stop the leakage there. I don't have too much experience messing with carbs but I've messed around with previous two strokes and tuned them a little better. I change the oil on my bike after 15-20 hours on it and clean and oil the air filter after almost every ride. The sparkplugs never last me more than a few months but recently have been lasting me no more than a few weeks. With the excess oil from the pipe and spark plug fouling you can see why I need to set my bike up to stop this. 
      The bike:
      Completely stock with V-Force 3 Reeds and a FMF Shorty silencer. 
      Usually running around 32:1 premix with 91 pump fuel because I prefer to keep it well lubricated instead of running rich.
      Riding:
      I ride enduro in Ontario, Canada. So mostly single track and some fire roads but nothing close to MX and not a lot of time wide open. Therefore, probably mostly 1/4-1/2 or 1/4-3/4 throttle range.
      Where I ride:
      Usually 0-500' above sea level. With temperatures ranging from around 15-35 degrees Celsius (55-95 Fahrenheit).
       
      If anyone can give me a setup to go from, that would be very much appreciated. Even multiple set ups for different temperature ranges or any suggestions would be much appreciated. Thanks and sorry for the long read, I just didn't want to leave anything out. Ask any questions if you have any, too.
    • By Charles Joseph Miron
      Hello all.  Need a helping hand here..  
      I bought an older TT225 and am not about to spend almost $600 on a new carburetor for it. So I'm hoping someone can help me out with an idea of what (other than original carburetor) style, type and brand I should go with..  I'm also having a bit of trouble finding info on this bike.  It's a 1986 Yamaha TT225.  
      Thank you in advanced
      Charles
×