How to Take Measurements For Boat Throttle and Shift Cables

If you have an older boat, the time may come to change out some control cables. So how do you go about determining which cables are going to fit on your boat? 

You’ll need to know not only how to measure control cables, but also which ones to order. When it comes to the control side versus the engine side of these cables, it can get confusing with all the different applications and configurations. But if you take your time, do some research on your boat, and take pictures of what you've got, then you should be able to line up what cables you need to replace. Here’s how to take measurements for replacement boat shift and throttle cables. 

Universal Boat Control Cables

Universal control cables are exactly what they sound like. These cables have the same fitting on both ends for the engine and control sides for whatever manufacturer and generation you’re dealing with. 

OEM Boat Control Cables

If you don't want to use universal cables and prefer to go with an OEM replacement, you have to be careful about which type you're ordering. For example, in the video above we have Mercruiser Gen 1 and Gen 2 cables. The Gen 2 cable has the standard engine connection, but the control side looks more like a universal cable. 

The Gen 1 cable has a standard engine connection, but then it also has a completely different attachment point for the control side. 

There’s a large family of cables available anywhere from the Mercruiser Gen 2 to the Gen 1, OMC, and the universal types. The trick is finding the correct end, because you've got different diameters going from a 10/32nd, to a quarter inch, all the way up to a 5/16ths in a variety of applications. 

Once you know the right cable type for your boat, you need to measure how long it needs to be. For our particular application in the video above, it’s for a Mercruiser inboard. There are several measurements to make for this boat. We need to go from the control down the length of the boat to the stern. 

We then have to measure from the stern to the halfway point of the boat itself, which is the center line of the engine. Also, we need to add any distance we have in elevation plus the distance from the center line to the control point itself.  We’ll also to have to take into account measurements for the throttle side, and a linkage side for the shifting. 

Whatever the center line number is works in this case for the shifter side, but for the throttle side, we’ll add another foot to that to give us enough wiggle room to get everything in there. 

NOTE: For an outboard instead of an inboard, you can measure it the same way, but then add 4 feet to your measurement to account for the amount of play to where it can track the engine as it goes through its arc. 

Measuring a Boat to Find Control Cable Dimensions

Measurement 1: Measure from the control down to where the cable is routed.

Our Measurement: 2 feet

Measurement 2: Next, measure back to the stern itself, where the cable is going to turn. 

Our Measurement: 12 feet

Measurement 3: Measure to the center line of the boat. 

Our Measurement: 3 feet

Measurement 4: Looking at the top of the engine, roughly a foot forward from the center line to the control point. 

Our Measurements Calculation: 2+12+3 +1= 18’ (shift side) and 19’ (throttle side)

Once you have your control cable measurements, you’re ready to order new cables and replace them. If you’re looking to test control cables, check out our video below on how to test cables with a control cable tester.

Looking to do some maintenance on your boat’s control cables instead of replacing them? Watch the video below to see how to do maintenance on outboard throttle cables.