Prop ??

[mad8713]

Now that I have the alarm problems straightened out I am looking to get a better prop.I have a 200hp mercury on a 22mako.(20 inch shft) Right know I am running a 17p. Not sure of the diameter. The wot rpm are around 5850. Doesn't seem to change with full tank of fuel or extra people on board. The one thing I noticed is right when the boat is about to plane, the prop seems to break loose for about a second. The rpms don't jump, it just sounds like it. I was thinking I should up the diameter.(what ever it is). Any suggestions on the prop size and diameter?????

 

[LubeDude]

Re: Prop ??

Assuming you are now running a stainless prop, I would think you could turn a 19P, 14.25 ? If not, go to a stainless 17P in the same diameter you have now.<br /><br />The slight bit of cavitation you are experiencing is ok, it lets your engine gain a few RPM for getting out of the hole. Is there holes drilled behind the leading edges of the blades on the prop you have? If so, thats why they are there.

 

[ronmold]

Re: Prop ??

17p seems a little low for a 200, I would think a 19 would be better BUT you are in the right rpm range. 14.25 dia. would be "standard" for a large gearcase for a 3 blade. Is it a heavy boat and are you running a stainless?

 

[mad8713]

Re: Prop ??

THe boat is heavy. it is a old mako. The previous own built a t top out of ss and built a storage box out of wood and glass in the bow. Right now am not run a ss prop but would like to upgrade to one.

 

[ronmold]

Re: Prop ??

17 might be OK then, What is your diameter? Often an aluminum that has been re-worked, ding repair etc. start to lose their diameter. a 17 4 blade stainless would drop RPM's a tad 100-200 and give a better grip when getting on plane.