Frame drain plug on YZ 450 ?

14 replies to this topic
  • couly

Posted June 19, 2002 - 04:32 PM


It sure looks like a frame drain plug on the new YZ 450. It even looks higher than the aparent fill plug on the shifter side of engine case. Anyone know the details?

  • Bambislayer

Posted June 19, 2002 - 05:48 PM


I was told that is the nitrous blow off valve.

  • Guest_mxrider426_*

Posted June 19, 2002 - 05:57 PM


I am pretty shure that the 450 is still dry sump. If it was wet sump, then they would brag about it, but all they said was "reduced oil capacity". I didn't think that yamaha would make the 450 wet sump since it didn't recomend wet sumping the 426.

  • Fastest1

Posted June 19, 2002 - 07:42 PM


I thought I had read they quit storing the oil in the frame and increased the crankcase capacity. But still not up to the original total capacity. Still dry sump. They say alot to get us to buy their equipment (it is their job). Do you think dry sumping is for improved control of lubrication or performance? Though without lubrication increased performance wont be the result LOL. They talk out of both sides of their mouth about performance issues because R1s & R6s have wet sump motors. Just a thought. Hard landings though I am sure cause momentary lubrication problems. :)

  • Norman

Posted June 20, 2002 - 04:20 PM


True about the R1's motor being dry sump but Ive also read not to get too good at wheelies because of oil starvation, dont know if that would affect a dirt bike though, but then again my R1 holds about 3 1/2 quarts of oil in the motor.

99 R1
01 YZ426

  • Bambislayer

Posted June 20, 2002 - 06:03 PM


Norman your R1 has a wet sump engine as all streetbikes do. The oil starvation happens because of where the oil pickup is located in the sump and it would not happen if it were dry sump due to the constant pressure of oil entering the top end. just some info for you.

  • Manic

Posted June 20, 2002 - 07:25 PM


The R1 is a wet sump but your mistaken about all street bikes being wet sump.

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  • GYT-Rider

Posted June 21, 2002 - 08:58 AM


The bike is dry sump.

Check out the technical info about the engine in this site.

  • Mark_UK

Posted June 21, 2002 - 09:09 PM


i dont see where it says its 'drysumped'

  • GYT-Rider

Posted June 21, 2002 - 09:25 PM


If you press the technical information button, and then the picture of the engine. Then scroll down to to the bottom of the page. You will find engine info:

Type Liquid cooled, 4-stroke,single cylinder, DOHC 5 valves
Displacement 449 cm3
Bore and Stroke 95.0 x 63.4 mm
Compression ratio 12.5:1
Max. Power N.A.
Max. Torque N.A.
Lubrication Dry sump
Fuel supply Carburettor (FCR39H)
Clutch type Wet, multiple disc
Ignition C.D.I.
Starting system Kick
Transmission Constant mesh, 4 speed
Final transmission Chain
Gear ratio 1 1.929
Gear ratio 2 1.563
Gear ratio 3 1.278
Gear ratio 4 1.05
Primary reduction ratio 2.818
Secundary reduction ratio 3.357

  • Bambislayer

Posted June 21, 2002 - 10:48 AM


tell me of a streetbike that has a dry sump engine please because I do not know of any. No sportbikes are dry sump.

  • Cobra314

Posted June 21, 2002 - 11:08 AM


I talked to the owner the dealership where I am getting my 450 that went to the Dealer show. He said they still have some oil in the frame and that is the fill plug. He said most of it is in the engine though.

  • moto614

Posted June 21, 2002 - 11:38 AM


Harley/Buell are dry sump but they are more lawn and garden equipment than street/sport bikes :) :D :D


  • Norman

Posted June 21, 2002 - 03:48 PM


Sorry, typing mistake on the dry/wet sump, I know that, pretty funny about the Harley/Buell lawnmower thing though.


  • Scott_F

Posted June 22, 2002 - 02:08 PM


The '03 YZF's have the oil filler on the ignition cover, but the oil is still pumped up to the downtube reservoir for a dry sump motor.

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