siezed rod bearing

[J-Dawg]

I have a 99' 400f with a siezed rod bearing.When I took the oil filter out it was collapsed somewhat.I am thinking I did not have full oil flow throughout the motor.Also I am putting the White Brothers 420 kit on. Has anyone had any problems with this kit?

[ian040207]

I've just had my connecting rod bearing sieze up. I have already pulled the motor out. Can you just buy a new bearing, or does it come in a complete kit?

[642MX]

Wow, this is an old thread.

Anyways, the crank comes as a complete assembly or piece by piece. I just replaced my crank not long ago. We don't have any good machine shops close by to rebuild cranks, so it was easier to get the assembly.

Welcome to TT. ?

[stnkbg1]

Mine did the same recently. Since the motor had lots of hours on it I went ahead and put in a 426 crank, piston and cylinder. This thing is an animal now. It always had lots of power, but damn is it getting it now.

[Speedracer747-400]

If you want to convert your YZ400F to a YZ426F this can be done using factory oem Yamaha parts. The YZ426F connecting rod uses a larger piston pin giving you a little better reliability.

Here's the parts needed to do the conversion:

(1EA) 5BE-11681-00-00 YZ400F CRANK PIN

(1EA) 93310-634B0-00 YZ426F CRANK BEARING

(1EA) 5JG-11651-00-00 YZ426F ROD, CONNECTING

(1EA) 5JG-11631-10-00 YZ426F PISTON (STD)

(1EA) 5JG-11603-00-00 YZ426F PISTON RING SET (S

(1EA) 5JG-11633-00-00 YZ426F PIN, PISTON

(2EA) 93420-19084-00 YZ426F CIRCLIP

(1EA) 5JG-11181-00-00 YZ426F GASKET, CYLINDER H

(1EA) 5BE-11351-00-00 YZ426F GASKET, CYLINDER

(1EA) 5JG-11311-00-00 YZ426F CYLINDER 1