good motor mods for '00 yz426

10 replies to this topic

Posted January 17, 2005 - 10:34 PM


im in the process of putting my motor back together(seized the bottom end thanksgiving weekend at glamis) and i was wondering what you all think would be the best mods for me to do while its apart. im replacing all the bearings, auto decomp camp, and hi-comp piston. if i do the exhaust should i also do the intake cam? and will be doing the '01 clutch mod too.

  • Fastest1

Posted January 17, 2005 - 10:45 PM


No need for the intake cam.

  • Matt96xr6

Posted January 18, 2005 - 07:57 AM


Get the JD jet kit and do the BK mod to the carb. You should have more than enough power

  • yz426onNOS

Posted January 18, 2005 - 08:19 AM


13.5.1 compresson, larger bore, hot cams both exhaust and intake they include the auto decompressor, kibble white SS one piece valves are a must! Maybe even porting and polisihing.

  • Chills

Posted January 18, 2005 - 12:19 PM


Hey YZ426onNOS,

Can you shed some more light on the kibble white SS One Piece Valves for me...Thx Bro

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed

Posted January 18, 2005 - 08:23 PM


ive already done the BK carb mod and was planning on getting the JD jetting kit, just forgot to mention that.

yz426onNOS, if only i had the money... but, if i did have the money, it would be a stroker crank plus big bore equals 488cc. 13.5 piston, web cams, port and polish, and kibblewhite SS valves. that sounds about right. too bad its all out of my league $$ wise.

oh yeah, i ordered the hot cams auto-decomp exhaust cam today as well as the hi-comp piston.

  • blue_beast_wins

Posted January 18, 2005 - 08:40 PM


Drill and tap the breather hole in the case beheind the barrel, best to do it while the cases are split. :cry:

  • drc02

Posted January 18, 2005 - 08:56 PM


replace the crank bearings with ceramic

  • Bryan47

Posted January 19, 2005 - 04:25 AM


Ceramic?? Where do you get 'em?

  • myoung

Posted January 19, 2005 - 09:51 AM


Check the transmission gears for excessive wear.

  • Vibeguy

Posted January 19, 2005 - 02:50 PM


Forget the ceramic bearings, way over priced and the only advantage is more resistant to chemical attack, unless of course you have a chronic chemical attack on your big end!

My personal favorite, the TT decomp plug!

Related Content


Snake pit oct 30th by The Anvil

Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  293 replies

BIGBORE FOR YZ450F 2006? by Taattie94

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 5 replies


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  30 replies

Wilson the Blue Privateer by jetfuel

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  50 replies

Megabomb Fitment by 288yz450

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.