17p aluminum to 19p stainless??

[BOONEX]

hey all i was wonderin if there would be any noticable differnence if i swaped out my 17p oem alumiumn prop for a 19p cabellas stainless..i bought the ss for my 90hp mercbut didn getit running so i ended up buying a 89'70hp merc to replace it id love to use the SS instead of the aluminim but not sure what to expect....i belive ive read here at some poin hat the lower the pitch the higher the RPM?? is this correct so the swap o the 19 would lower rpms right?

 

[Laddies]

Re: 17p aluminum to 19p stainless??

If you engine is proped right now, it will never get into the right RPM range and will be gutless out of the hole

 

[BOONEX]

Re: 17p aluminum to 19p stainless??

If you engine is proped right now, it will never get into the right RPM range and will be gutless out of the hole

well to be quite honest i havent really tryed it out much from what i can tell the holeshot seemed to be pretty much gutless now it seemed great on top end i dont have a tach and didnt have the gps with me ....maybe im just used to my 82'90hp inline it seemed great outta the hole the 70 seems alot slower outa the hole but didnt notice much top end differnce what i did notice on my little cable set up and trial was the differnce in fuel the 70 from what ive seen could cut the 90 in half if not more

 

[Silvertip]

Re: 17p aluminum to 19p stainless??

Just the difference in pitch between the two props will lower engine rpm from 400 - 500 RPM. Without knowing what rpm and speed the 70 was turning with the 17P, and since we also have no idea what boat, size, and load you have there is no reasonable way to determine if the 19P will help or hinder but I will take a wild guess and say if it was a pig out of the hole before it will be a real big pig out of the hole with the 19P stainless. The best prop is the one that allows the engine to run within the manufacturers recommended rpm band at wide open throttle with a normal load. Too many revs you need more pitch -- too few revs you need less pitch. Whatever speed that provides is what you get. Playing with engine mounting height can optimize the setup to gain a little top end.

 

[Silvertip]

Randy you just hijack this thread -- why? Your question has absolutely nothing to do with Mercury/Mariner outboards and nothing to do with this thread. If you scroll to the bottom of this page you will find the word BOATS (250+ manufacturers) under BOAT MANUFACTURERS. Go there, click on your boat type and ask your question.

EDIT - The off-topic hijack was moved to a more appropriate new thread in General Boating, Non-repair. Silvertip is not hallucinating! GA_Boater