Merc 5hp & 6hp difference?

[wooly15]

I recently picked up a 2004 Merc 5hp four stroke tiller and started doing some research. I compared it to the same year model 6hp and noticed that the only difference was higher RPMs on the 6hp. Is that all it takes to make it qualify as a 6hp? If so, whats the point of offering two engines with such a subtle difference?

 

[TOHATSU GURU]

Re: Merc 5hp & 6hp difference?

Different carb. The 5 is a 6 hp engine with carburetor that only lets the engine develop 5 hp at WOT. It's cheaper to build an engine and retard it down rather than purpose build every single hp size.

 

[kingsnakejr]

Re: Merc 5hp & 6hp difference?

Guru,
I had the very same question about the difference between a 18xd and 25xd.
Laddies said the difference was the tuning pipe. What is the tuning pipe and why is it no longer available?

 

[TOHATSU GURU]

Re: Merc 5hp & 6hp difference?

A "tuning pipe" refers to the exhaust tube under the powerhead that can be found on many outboards. I have no idea what an 18XD or a 25XD is so I can't tell you anything about parts availability for them.

 

[wooly15]

Re: Merc 5hp & 6hp difference?

Different carb. The 5 is a 6 hp engine with carburetor that only lets the engine develop 5 hp at WOT. It's cheaper to build an engine and retard it down rather than purpose build every single hp size.

Would the 6 hp carb bolt directly on the 5p engine with no modification?

 

[TOHATSU GURU]

Re: Merc 5hp & 6hp difference?

Yes, you can make a 5 into 6, a 5 into a 4, a 6 into a 5, a 6 into a 4, a 4 into a 5 or a 4 into a 6. All with no modification other than a carburetor replacement.

 

[wooly15]

Re: Merc 5hp & 6hp difference?

Yes, you can make a 5 into 6, a 5 into a 4, a 6 into a 5, a 6 into a 4, a 4 into a 5 or a 4 into a 6. All with no modification other than a carburetor replacement.

Roger that! thanks Guru