wild HP 300 rebuild
 

Well guys it's time to rebuild my much loved wild HP300 quad, so far i've rolled it, squashed 2 mufflers and twisted the balance shaft, after much reading i put the motor back together without the balance shaft which cracked all my engine mounts and learn't me a few lessons on vibration. so my question to you guys is while my majour rebuild is going on what mods should i do.

Vibrations are crazy without balance shaft, haha,

A larger radiator is a must, if you want to run fast!

Have you fixed the upper a-arms, to correct the castor, and reducing rider arms fadigue?

What all is involved in the castor fix?

Cut the upper a-arms and install uniball bearings. Know you can adjusting the nuts to correct the castor angle to normal values, lets say 2 to 4 degrees. Original setup has about 20 degrees!

I will send you a picture of my quad if you want.

Sent you a PM 2stroker. Thanks

I put the 2006 A arms on my 04 and they work great.

What is the difference between the two? I have an 03

The 2003 to 2004 have 50" wide a-arms. this is the first series.
From 2004 to 2006 are 2 options: first series or 48 " a-arms to make the front end of the quad narrower.

They also get the camber to 10 degrees which works well. I put 4-1 Hipers up front to suck it down a little more and it works great here in the Eastern woods. It's now around 47".
I wish Gas Gas would go back to the 300 engine in their quad. Everyone makes a good four stroke quad. They just never developed a market for this great machine.