Installing a Hand Throttle
The hand throttle was built for a number of reasons. First off, with a four-cylinder and a carburator, getting the Jeep to stay running while it's pointed uphill is a major battle, especially if you have to hold the brake and the clutch at the same time. Also, it makes starting on steep slopes and off-camber situations much simpler. Finally, it's useful for setting a higher idle while using my on-board air or welder system.
The first step in installing a hand throttle is getting the necessary parts. First, you need an “old school” style bike lever. It needs to only have 1 lever. These can be easily found at any bike shop. Second, you’ll need a length of cable with an exterior housing. Around 50-60 inches is suitable for most vehicles. This can be easily found online. Lastly, you’ll need a circular electrical connector for the gauge of cable you will be using. This will be used to attach the cable to carburetors throttle control.
Next, you will need to attach the lever controller to your stick shifters column. I had to add a band of 1/8 inch metal around the column so the lever would fit snug, since it was much to large. Most bike levers are made for a 1-inch bar, and most vehicles have a ¾ inch column. Make sure you mount it in a comfortable position for easy reach with your fingers. You want to be able to move it up and down with your middle and index finger.
Next, you’ll need to bring the wire down the column, through the transmission access plate, and into the engine compartment. This is the cleanest way to do it.
Next, you need to find where your throttle linkage is. Mine was next to the exhaust manifold, a well way away from the actual carburetor. Crimp a circular electrical connector to the end of the wire, remove the current throttle cable off the stud, slip the electrical connect on the stud, and then put the throttle cable back on. This will ensure that the hand throttle cable will stay put.
Lastly, you will need to secure the exterior part of the cable to a fixed mounting point. Every engine has different components, so you will need to search around for a place to mount it. On my 4-150, I was able to remove a bolt on the EGR valve, slip the cable right next to it, and then snugly tighten down the bolt again. This ensured the exterior part of the cable wasn’t moving anywhere, which is crucial to the hand throttle system working.
Now its time to test it out. First jump back inside, and move the lever up and down to make sure there are no obstructions in the cable. Once you can freely move the lever up and down, put the vehicle into neutral, with the parking brake on. Be ready to shut the vehicle off incase the engine revs way up, as it did when I first tested mine. Turn the vehicle on, and slowly move the lever. The RPM’s should climb up steadily. You need to get a feel of how much lever movement equals number of RPM’s. Now, you can take it for a test drive.
I had to add an extra spring on the throttle linkage, since the existing one was small and weak. When I gave it gas via the hand throttle, it wouldn’t return once I released the lever. An added spring fixed that.
author: Darek from NEOW- (reprinted with permission ©2004 Daywreck)