Olds Mechanical Engineers and Founders - Innovative Engineering Excellence

OLDS ENGINEERING     Marine Division

ProPulse Frequently Asked Questions

What material is ProPulse made of?
A high density composite, which is the same material race-car parts are made from. Also, some new outboard power heads are made from similar composites.

Is the material strong enough?
The composite that is used for ProPulse is stronger than aluminium and  resistant to corrosion and cavitation damage. The hub has a 3 year guarantee.

Does it fit to my engine?
ProPulse fits all of the most common outboard brands and stern drives between 18 and 300Hp (see motor specification)

Why four blades instead of three?
A four blade propeller is easier to balance and has a better grip in the water. It has more traction, smoother operation, quicker acceleration, better cornering and handling and holds the boat on the plane at lower RPM.

How many different pitches can be adjusted?
4901 and 4902 - 11"-17"  with 7 pitches
6901 and 6902 - 11 "-17"  with 7 pitches
8901 and 8902 - 15"-21"  with 7 pitches
9901 and 9902 - 14"-22"  with 9 pitches

How can you adjust the pitches?
By slackening the bolts approx. 4 turns, so that the ring can be lifted about 2mm. The chosen pitch can be set by turning two opposite blades whilst watching the pitch gauge. The pitch is locked by retightening the bolts crosswise. (see operating instructions "Adjusting the pitch")

What is the advantage with adjustable pitch?
You can optimise the rpm of your engine and get the best performance from your combination of boat and engine ie. highest speed, lowest fuel consumption and best holeshot.

What pitch is correct?
At full power your engine should run at the correct specified rpm range (see instruction Manual for engine). It is harmful to run the engine above or below the recommended range. If maximum rpm is too high or low, adjust the pitch until correct.
To increase by 200rpm Reduce the pitch by one increment.
To decrease by 200rpm Increase the pitch by one increment.

What is the advantage of replaceable blades?
If the Propeller is damaged, it is easy to replace blades on the spot and carry on immediately with your trip. It is cheaper than a repair or buying a new propeller. Also, this is more accurate than a repair.

How do I change blades?
By unscrewing and removing the four bolts so that the ring and the rear hub section can be removed and the damaged blade replaced. (See operating instructions "How to replace the blades")

Do all four blades break if I run aground?
The blades are designed to snap off in the event of the boat running seriously aground. This is to prevent damage to the engine and transmission (most commonly, only one or two blades will break). When this happens to an aluminium prop all three blades will brake and the bushing generally goes as well.

Do ProPulse Propellers fit stern drives also?

What is the size difference between 3 and 4 blade propellers?
As a general rule when converting a 3 blade prop size to a 4 blade prop size, you would reduce pitch by 1". For example, a 17" pitch 3 blade propeller would become a 16" 4 blade propeller.

Order Your ProPulse Propeller Now

Wm. Olds & Sons Pty. Ltd. trading as OLDS ENGINEERING
78-80 North Street, Maryborough Q, 4650 Australia
P.O. Box 3030, Pallas St. Post Office, Maryborough Q, 4650
Phone: 07 4121 3649 Fax: 07 4123 3590 International Phone +61 7 4121 3649 Fax: +61 7 4123 3590

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