What is the correct way to measure shaft length ?

[fishon71]

I have 1988 Evinrude 8 hp extra long shaft. Looks like spacer measures 10". I want to know where to where do you measure an engine to tell someone the exact shaft length. What is the shaft lenth on this engine?<br /><br />Model# E8SRLCCS<br /><br />Thanks

 

[Joe Reeves]

Re: What is the correct way to measure shaft length ?

Measure from the underside of the transom brackets (the portion that would rest on the transom top) to the cavitation plate that exists just above the propeller.<br /><br />Short shaft = 15"<br /><br />Long Shaft = 20"<br /><br />Extra Long Shaft = 25"

 

[fishon71]

Re: What is the correct way to measure shaft length ?

Okay I confirm how to measure, thanks. What is a standard length then 20 inches?

 

[fishon71]

Re: What is the correct way to measure shaft length ?

This one has two cavitation plates, from transom mount to first is 25" and second is 28" so what's up with that? What do I call it ????

 

[seahorse5]

Re: What is the correct way to measure shaft length ?

That's a sailboat motor. They have a very long exhaust housing to reach the water while hanging off the back of the blow boat.

 

[rickdb1boat]

Re: What is the correct way to measure shaft length ?

What do I call it ????

Extra Long Shaft.....

 

[fishon71]

Re: What is the correct way to measure shaft length ?

Very good, I know its a sail boat motor, question is " what is the length 25 or 28 inches" as I explained from post before by the measurements.

 

[Silvertip]

Re: What is the correct way to measure shaft length ?

As was pointed out, measure from the bottom of the transom bracket to the AV plate just above the prop. Forget about anything in between these two points. Take the measurement with the engine vertical. There is no "standard" length as various engine sizes have different shaft lengths. Small outboards generally are 15-inch but have optional lengths (kits) available. Mid range are generally 20, high end motors are 25. Just guessing, but since your small motor is normally a 15" in standard configuration, addition of the 10" spacer would make it a 25".

 

[rickdb1boat]

Re: What is the correct way to measure shaft length ?

Agree with Upinsmoke. If anyone asks, it would be a 25" shaft motor...

 

[fishon71]

Re: What is the correct way to measure shaft length ?

Okay, I'll call it 25 inches even though it measures 28" I guess... the extra 3" is in between the two cavitation plates. This is not a spacer though. The spacer measures 10"

 

[seahorse5]

Re: What is the correct way to measure shaft length ?

If I remember correctly, a sailboat motor is considered to have a 30" shaft.

 

[fishon71]

Re: What is the correct way to measure shaft length ?

Oh, confuse me more!

 

[rickdb1boat]

Re: What is the correct way to measure shaft length ?

 

[rickdb1boat]

Re: What is the correct way to measure shaft length ?

Look like this?<br /><br />

 

[Paul Moir]

Re: What is the correct way to measure shaft length ?

Often small outboards measure a little longer. On the side of the 8hp engines I've seen there's a water bypass just above the cavitation plate that must be submerged at idle. It looks just like other outboards with an exhaust/water intake "fin" rather than thru-hub. Perhaps that's the reason they make them a bit longer.<br /><br />So always round down (within reason) to the nearest 5" increment when measuring.

 

[fishon71]

Re: What is the correct way to measure shaft length ?

Very good, great information, I confirm its an extra long shaft 25" thanks