Power Take Off (crankshaft) Pulleys

The top left picture on the right is a crankshaft PTO (Power Take Off) pulley we manufacture that allows for the attachment of a twin belt alternator. Below that is a similar pulley using a serpentine belt instead of a twin V-belt solution. We stock the PTO pulleys that fit (bolt on to) the Yanmar engine crankshaft pulley.

The picture on the far right top is a 4 sheave PTO pulley that is designed for significantly larger engines that feed multiple power take off options. This type of PTO requires additional horsepower and the availabilty of room around the engine in order to allow for the attachment of the options.

For other manufacturers, we are able to custom create (special order) a PTO pulley or a new replacement pulley that will be the combination of the main crankshaft pulley (one or two sheaves) plus a 2 sheave PTO. The end result is a new bolt replacement pulley for the crankshaft with three or four sheaves that will accomodate all of your needs to mount v-belts. Pictured at the far right bottom, are a couple of examples that required widely different specifications.

Standard Yanmar 2 Sheave PTO - edge view

Standard Yanmar Serpentine PTO - edge view
Standard Yanmar 4 sheave PTO - edge view

Very Custom 3 sheave PTO    Very Custom 2 sheave PTO

Specialized Pulleys

Depending on your situation, we may ofer to custom create (requires a special order) a new replacement pulley for most items attached to your power plant or accessories in order to have a proper total solution. The costs associated with this option varies widely depending on what is required, complexity of fabrication and the man hours that may be required. A free phone consultaion is always available in order to get initial estimates for your situation.

Pictured at right, is a completed one-time installation that had it's 3/8" single sheave crankshaft pulley modified to become a 1/2" single sheave version, a new 1/2" water pump pulley was made to replace it's previous 3/8" one. We do not provide this service as a regular product - it is only displayed here to show capabilities. Due to the additional side loading on water pump components created by alternators exceeding the 94 amp level has reportedly led to premature failures, ZRD will not provide this specific service due to factors beyond our control that may lead to overloading and failures.

Completely Custom Refit of small Westerbeke

The important item of significance to note here is that the modified crankshaft pulley and the new water pump pulley were created in such a way as to ensure the alignment of the newly created sheaves with each other and the replacement alternator's sheave. This technique is applied when we design PTOs / Replace Crankshaft Pulleys for PTO attachment for our Second Alternator High Output soultions. In order to ensure a proper fit, you will need to send us your existing pulley(s) and any associated & co-located hardware (washers, bolts, balancers, ...).

Special Note:
If any hardware sent to ZRD is not easily replaceable via the manufacturer or a parts supplier, ZRD must be notified in advance prior to shipment to ZRD. ZRD's only accepted liability is to a pre-arranged agreed amount ($) in the event should damage or loss of non-replaceable customer hardware occur after ZRD receipt of customer hardware and prior to customer's receipt of a completed order. The completed order shipment will contain all customer supplied hardware in addition to the ordered components. If no order is placed after ZRD receives a customer's hardware, customer agrees to assume full sole responsibility for return shipment charges and any and all liability for loss or damage. If customer does not request the return of any of his supplied hardware within thirty (30) days of receipt by ZRD, customer relinquishes all claims to supplied hardware. Under no circumstances, shall ZRD's maximum accepted liability for any loss or damaged customer hardware to ever exceed $500.

ZRD Alternator Pulleys (In Stock - Special Order)

Following ZRD stock pulleys are machined to work in conjunction with standard engine or ZRD custom PTOs to enable/ensure correct engine/alternator operation range. They are for use with large and X-large case high-output alternators with 7/8" shaft bore.

Part Number Description Dia. Belt Width Bore 
ZP782240 Dual Groove 2.40" 1/2"  (2) .875"
ZP782270 Dual Groove 2.70" 1/2"  (2) .875"
ZP782300 Dual Groove 3.00" 1/2"  (2) .875"
ZP782325 Dual Groove 3.25" 1/2"  (2) .875"
ZP782350 Dual Groove 3.50" 1/2"  (2) .875"
ZP782425 Dual Groove 4.25" 1/2"  (2) .875"

ZP78S240 Serpentine 8-Groove 2.40" 1.125" .875"
ZP78S270 Serpentine 8-Groove 2.70" 1.125" .875"
ZP78S300 Serpentine 8-Groove 3.00" 1.125" .875"
ZP78S340 Serpentine 8-Groove 3.40" 1.125" .875"