0

Your Cart is Empty

How To Find The Correct Pulley Kit

October 11, 2021

Pulley kits can be confusing and difficult to determine which one is correct for your generator. The KSI and CSI generators use an aluminum idler pulley. The blower fan is mounted to the idler pulley. Please note, on some units, Power Tech installed a fan clutch.

Why do you need to replace your pulley system?

There are a few reasons why it might be time to replace your pulley kit. In most cases, it’s one of two reasons. One reason is your bearings have failed within the idler pulley. This would cause your blower fan to shake and create vibration due to it becoming unbalanced. Another reason why your pulley kit would need to be replaced is over time your aluminum idler pulley wears in the center where the belt rides. You’ll notice the belt is slipping and your blower fan isn’t engaging to blow air. As a result, your generator will overheat and activate the high temperature switch and shutdown.

Now that you know your pulley kit has failed, which kit do you need?

KSI and CSI generator pulleys were modified and often updated over the years to better improve the generator’s cooling system. Because of the modifications, it can be difficult to find the correct pulley kit for your generator. Pulley kits are sold with the blower fan and without the blower fan. Often times the fan is damaged when the pulley fails and is always a good idea to replace it when replacing the pulleys.  

Here are a few things you’ll need to know before purchasing your pulley kit.

  • Identify the generator model
  • Remove and measure the center mounting hole on the blower fan.
  • Measure the diameter of the water pump pulley.

Identify the generator model

There’s a difference between the CSI and KSI models. The KSI generators use a Kubota diesel engine to power the generator and the CSI generators (discontinued model) used a Caterpillar diesel engine to power the generator. Both models are available in 8, 10, and 12 KW sizes. If you're looking at your Power Tech serial number, KSI serial numbers start with a K and CSI serial numbers start with a C. Below, you'll see a more in depth breakdown on Power Tech serial numbers.

KSI Model Generator Serial Numbers

Example of a KSI Serial Number: KNM21DDD1234

The first letter in the serial number represents the engine type. For all KSI model generators, it will start with a "K" for Kubota. The second letter in the serial number represents the engine model. This may vary depending on the KW size of the generator. "N" represents the Kubota D1105 and "J" represents the Kubota D1505. The Third letter in the serial number represents the generator end used on the generator. "C" represents Colussium and "M" represents Marathon.  

To breakdown the serial number in the example above:

K = Kubota
N = D1105
M = Marathon Generator End

CSI Model Generator Serial Numbers

Example of a CSI Serial Number: CAM21DDD1234

The first letter in the serial number represents the engine type. For all CSI model generators, it will start with a "C" for Caterpillar. The second letter in the serial number represents the engine model. This may vary depending on the KW size of the generator. "A" represents the Caterpillar 3011 and "B" represents the Caterpillar 3013. The Third letter in the serial number represents the generator end used on the generator. "C" represents Colussium and "M" represents Marathon.  

To breakdown the serial number in the example above:

C = Caterpillar
A = 3011
M = Marathon Generator End

Remove and measure the center mounting hole on the blower fan.

By removing the blower fan from the generator, you will be able to take an accurate measurement of the center mounting hole on the blower fan. The measurement will read 2 1/2 inches or 4 3/4 inches in diameter. Power Tech’s current KSI pulley setup is 4 3/4 inches on the blower fan mounting hole. If you have the 2 1/2 inch fan setup, it can be upgraded to the 4 3/4 inch mounting style if you purchase the pulley kit with the fan included.  

NOTE: When installing this upgrade, you’ll need to cut the shroud for fan clearance.

Measure the diameter of the water pump pulley

When purchasing a pulley kit, belt sizes can be an issue. The belts that are included in the pulley kit are determined by the size of the idler pulley and the water pump pulley. In each kit description, you’ll see a reference to the diameter of the water pump pulley. To reassure that you’re ordering the correct kit, please take the measurement of the diameter of the water pump pulley.  

Water Pump Pulleys

PT# 03PDRFAN...................................3 inches
PT# 03PDRFAN-3011..........................3 1/4 inches
PT# 03PDRFAN-L................................3 7/8 inches