YFZ450 Connecting Rod Application

***cross posted in ATV forum for max information gathering***

I searched the forum for answers. Could not find a disscussion on the topic.

Here is the bottom line...

I wanted a 20mm small end wrist pin for my 2008 YAMAHA WR450F.

To do that you need to run a YAMAHA YFZ450 Connecting rod.

I cannot find the length of the 2 connecting rods to compair. I was told earlier model 04-05 YFZ had a LONG connecting rod(102.50mm) and 06-up had SHORT connecting rod(101.50mm)-is that correct?

I bought this Falicon connecting rod-


Did I make the wrong choice in connecting rods? The description says 06-up.

Falicon has 06-up and 07-up with 2 different part numbers.

I was confident this YFZ Falicon connecting rod can be directly pressed onto my WR450 crank was I mistakened?

Why did you want to run a 20 mm small end rod?

Why did you want to run a 20 mm small end rod?

The WR450 Comes with an 18mm small end rod.It becomes a "weak link" in the motor system when an increase in force is put on the crank and rod.Thus the upgrade to the connecting rod itself.

More complicated questions.....

So the OEM 2008 WR450F connecting rod is 103.5mm long.

A WR450F CP 98mm piston has a compression height of (from centerline of the wrist pin to top of dome) .918

The 2006 YZF Falicon connecting rod I have in hand is 101.5mm long

The YZF CP 98mm Piston has a compression height of .983

If you add the WR set up (rod length/piston compression height) .918+103.5=104.418mm

If you add the YFZ setup .983+ 101.5=102.483

Why is this not adding up? People say they swap the WR setup to their YFZ? What is the deck height wokout to be on the YFZ?

I can see on my WR cylinder there is roughly 3mm before the WR piston reaches even with the deck height.OEM clearance calss for no less that .04.

Does the clearance end up really being nearly 5mm in the cylinder?

Create an account or sign in to comment

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

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now