I have a 1990 Honda trx 300 fourtrax 4x4 will the head and motor from 1993 2x4 fit Thanks Ray?

Yes, the head and motor from a 1993 Honda TRX300 2x4 will fit your 1990 Honda TRX300 4x4. The motors are very similar, and the only major differences are in the electrical system and the carburetor. The 1993 model has an electronic ignition, while the 1990 model has a points-based ignition. The carburetor on the 1993 model is also different from the one on the 1990 model. However, these differences will not affect the fitment of the head and motor.

Here are the steps you will need to follow to install the 1993 head and motor on your 1990 TRX300:

1. Remove the gas tank.

2. Remove the air filter cover and air filter.

3. Remove the spark plug wire.

4. Remove the valve cover.

5. Remove the head bolts and lift the head off of the cylinder.

6. Remove the piston and connecting rod from the cylinder.

7. Install the piston and connecting rod from the 1993 motor into the cylinder.

8. Install the head from the 1993 motor onto the cylinder.

9. Install the head bolts and tighten them to the specified torque.

10. Install the valve cover.

11. Install the spark plug wire.

12. Install the air filter and air filter cover.

13. Install the gas tank.

Once the head and motor are installed, you will need to make some adjustments to the electrical system. The 1993 model has an electronic ignition, so you will need to install an electronic ignition module and coil. You will also need to connect the wires from the electronic ignition module to the battery, ignition switch, and spark plug wire.

The carburetor on the 1993 model is also different from the one on the 1990 model, so you will need to install the carburetor from the 1993 model. You will also need to adjust the jetting on the carburetor to match the elevation and climate in which you will be riding your ATV.

Once you have made these adjustments, your 1990 TRX300 4x4 will be up and running with the new head and motor from the 1993 model.