Murcury 115 prop question

[kappout]

i was wonderin the best setup for my 115 merc... its an older model. im thinking a 76? but im not quite sure. also will a hydroplane improve my performance?

 

[Chris1956]

Re: Murcury 115 prop question

When you said hydroplane, you meant doelfin? If so, attitudes are mixed on them. Some like 'em, some hate 'em. For me it depends on the application. I would never have them on my speedboat and I don't need it on my bowrider. My neighbor loves his doelfin on his runabout.


Props are hull+motor specific. You have told us what motor. What kind of hull do you have? How long, is it trihull, flat bottom, vee of deep vee?

 

[kappout]

Re: Murcury 115 prop question

thank you for the prompt response!

and my current setup is the merk 115 with a hydrofoil on it. the boat is a mark twain 16'... i think its also a 1978.

 

[Chris1956]

Re: Murcury 115 prop question

Ok, What RPM at WOT? What speed at WOT? I would think a 16 foot mark twain should do at least high thirties- forty with a 115 tower

 

[Chris1956]

Re: Murcury 115 prop question

Baseline the the rig with a GPS and tacho, and remove the whae tail and try it again. You may find a difference. You may not need the whale tail, or it might be dragging. You may be able to raise the motor on the transom a bit and pick up some RPM and speed.

 

[kappout]

Re: Murcury 115 prop question

the boat does low 30s top speed. the tac isnt wired curtesy of the older brother and his friends, also the prop is shot... chewed up by iowas poor dredged lakes and... once again, the older brother.

 

[cell]

Re: Murcury 115 prop question

also the prop is shot... chewed up by iowas poor dredged lakes and... once again, the older brother.

I don't know how bad the prop is,but don't run it with a "shot" prop.You can damage other things.What are the numbers stamped on the prop?

 

[kappout]

Re: Murcury 115 prop question

ill take a photo of the prop and ill get those numbers for ya