How do you make a Baja Warrior minibike faster?

Answer 1

To make a Baja Warrior/Heat/MB200 6.45hp mini bike faster there are a few things you can do. The first and the one with the biggest payoff in terms of speed is to remove the governor. Essentially prepping the engine the way it would be prepped for Box Stock Kart Racing. Box Stock uses Honda clone engines (a copy of a Honda GX165 or GX200 engine as used in all Baja 5.5 and 6.5hp mini bikes).

First drain the engine oil. Then lay the bike on it's right had side and remove the clutch and then the jackshaft assembly (4 bolts around the crankshaft/output shaft of the engine and one at the back side of the jackshaft assembly plate. You can see it from the other side of the bike).

Then remove the engine from the bike (only 4 bolts).

Remove the gas tank from the engine.

You will see a long metal rod that comes from an activation arm that is fixed to a small shaft on the top of the engine case. that is the governor arm and rod. The shaft that the arm is bolted to goes inside the engine casing down to a centrifugal governor.

First disconnect the rod from the arm, then lift it and the spring that is wrapped around it out of the top of the carburetor. Put to one side, you will need the rod again.

Now on unbolt the arm from the shaft, you will not need this again.

Now lay the engine onto it's left hand side. so that the pull start is on the ground. unbolt the cover plate on the left side of the engine (the side the crankshaft come out). You will need to use an 8mm socket. once all the bolts are out, careful lift the cover off.

Now you can see inside the engine. You will see that the governor shaft is shaped like an L push it down from the outside so that it goes into the engine casing and then lift it out. You may not have enough room to pull it out. If that is the case push it back up again and cut the top off so it is shorter and now you will be able to push it out.

There is a black washer around the hole it went through, make sure you get that too, otherwise it will fall down into the internals and damage the engine, actually destroy the engine.

You will notice at the opposite side of the inside of the engine there is a small white plastic cog (that the governor arm pressed against) that is the centrifugal governor and that MUST come out.

What I usually do is gut through the spokes of the cog with a pair of strong wire cutters. You can then lift out the cog and all that is left is the shaft is was sitting on and the hub of the cog. That is fine you can leave that in.

Make sure you get any broken pieces of plastic out of the engine though.

Now put the side casing of the engine back on and bolt into place. The engine should have been laying on the right side (pull start side) the whole time.

Now you can stand it up. There's now a hole in the engine where the governor shaft used to be. Take a 5/16 bolt and screw it into the hole. It will cut it's own thread. that will block the hole and stop oil from coming out through it.

Now take the long rod that was on the activator arm and cut it down. It needs to go from the throttle arm (the arm that moves back and forth when you turn the throttle) to the top of the carb.

One end is already shaped like an L that goes into the top of the carb.

The other end is attached to the throttle arm. I usually attach it to the hole in the top of the throttle arm. Just cut it to the right length and make another L at the other end push it through the hole and then bend the top of the rod so it can't come back out of the hole.

Now put new oil in the engine. put the gas tank back on, put engine back in bike. Cost $0.

Now instead of the engine only revving to 3600rpm it will rev to 5300rpm. The top speed goes from 18mph to about 30mph without spending a penny, just a couple of hours of time.

Acceleration, staying power and top speed are greatly improved.

If you want more speed, go for a GTC TAV Torque Converter (replaces the normal jackshaft).

With those changes you will have even better acceleration and a top speed of about 50mph.

You can find lots of videos on how to remove the governor on a 6.5hp clone or Box Stock Preparation of a Clone engine or race preparation of a Honda or Clone engine.

DO NOT just bypass the governor, if it is still in there and the engine is revving to 5300rpm, the governor could fly apart and destroy the engine. It needs to come out, not just be bypassed.

It may take a little time, but it's well worth it. You get a massive increase in power for $0