outboard gears

[ibeiser]

Do typical outboard engines have just 1 forward and 1 reverse gear? Or are they like cars where the transmission may have 4 or 5 forward gears? (eg. most likely arrangement in my outboard which is a 2007 Suzuki 115hp 4 stroke or other comparable engines.)

Thanks and sorry if this question is too basic for this forum.

 

[erikpn]

Re: outboard gears

Do typical outboard engines have just 1 forward and 1 reverse gear? Or are they like cars where the transmission may have 4 or 5 forward gears? (eg. most likely arrangement in my outboard which is a 2007 Suzuki 115hp 4 stroke or other comparable engines.)

Thanks and sorry if this question is too basic for this forum.

1 forward, neutral, 1 reverse

 

[5150abf]

Re: outboard gears

that is how you learn is to start with the basics.

How a lower works is there are 3 gears, forward,reverse and a pinion gear, they are in an upside down U shape with the pinion on the drive shaft.

When the engine is running all the gears are turning and there is a clutch dog on the prop shaft that slides back and forth to engage the gears.

Thereis a basic description of how a lower works, pretty ingenious really.

 

[Chris1956]

Re: outboard gears

In addition, the water acts like the clutch in a car, and allows you to shift in and out of fwd and rev, at slow engine revs.

Having multiple forward gears wouldn't work on a boat because of the drag. You would slow down too much when you shifted gears.

There was a Power2prop some years ago which featured a shifting mechanism. In theory, when the motor reved up high enough the centrifical force would turn the prop blades adding pitch, and slowing the RPMs. This in turn could lead to higher top speed or faster out of the hole performance.

The props were expensive, and I do not think they were too popular.

 

[ibeiser]

Re: outboard gears

Thanks all. Appreciate the info.

 

[kenmyfam]

Re: outboard gears

Here's an interesting article that was posted by someone a long time ago on the subject. This is a copy and paste.

Why don't boats have more forward gears?


Yeah...it does seem sort of logical at first; doesn't it? But when you're running your boat; it's like a car going up a very steep hill all the time. Just cut off the power and notice how fast the thing slows to a stop...nothing like a car.

It takes a lot of power to keep a boat moving; unlike a car which has little comparable rolling resistance once it acheives a certain speed on level ground.

Marine engines are designed to produce that maximum power at high RPM's.....and would lug terribly if they were forced to run at lower RPM's (which could be obtained with the use of a different prop

Bad for the engine; terrible for performance. I think the closest we can come to more efficient "gearing" is through the more sophiscated props that are on the market today

 

[metriccrescentwrench]

Re: outboard gears

Actually some race boats use a transmission with multiple forward gears. However, that's a very specialized application and most of our boats would see little or no benefit compared to the added cost and complexity.