F1campion

I am currently running a 23P Mirage Plus and am turning toooo many RPM's. Also prop comes loose in 30-35 mph slaloms and just as the boat comes on plane unless i feather in the throttle. Last season I tried a 24P 4 blade and a 25P 3 blade. The 24P 4 blade never came unhooked and had incredible acceleration. The 25P gave me the best top speed but still came loose. I also noticed a little vibration at about 2000 rpm with the 24P prop but I think it was just the prop.

I have heard that my existing prop can be reworked to get my RPMs in par but I am skeptical about removing any material from the blades. I am skeptical because it seems that one would have to remove material to change the shape of the blade therefore making it weaker and more pron to flexing and fatigue.

What are my options? Could I ever get a 3 blade to stay hooked up?

O-ya ... did I piss everyone off or something? No replies to my last post.

HOUSTONPROP

F1 campion,your 23 pitch prop you said, you need to lower the rpm ,we do not have to reduce dia or thickness to reduce the current rpm,You need to have the pitch changed up 1 or 2 " in pitch,the 25 pitch you tried worked well except you mentioned it would not stay hooked up, a little cupping will fix this problem in the majority of all props,but,I would need alot more info as what RPM YOU ARE TURNING ON EACH PROP. also flexing will happen if the blades are too thin and the prop is not cooled properly(when)working on it, it takes time to do the job correct so you don't have someone ruin your prop,I do all the lab jobs at my shop and give each customer and their prop the same care as if it was my own prop. also four blade props are excellent ,it may just need balanced. Darin hope I have helped some?

F1campion

I am a little confused. If you had all info (RPM's) could you rework my existing prop to get me where I want to be, or should I start with a 25P three blade and cup it? Does cupping reduce top end?

HOUSTONPROP

yeswe need to know where each prop is running for rpm this will give us the info on which way and what needs to be done /cupping can increase the speed,but it can also slow the boat down if there is to much it is very critical as well as the rpm . we can achieve 600 rpm up or down to obtain max performance.

Waterfoul

This is Rambunctious on Waterfoul's login. i can't seem to log him out and be myself again!!!! anyway...

darin, would prop efficiency ( or slip measurement) tell you whether stepping to a 24 would be better than cupping a 3 blade?

seems 15% slip is about optimal from what little info i've found from mercury.

f1 champion. i think your boat acts similar to my formula 272.
i have 25 pitch 3 blades, they blow out if i hammer it trying to get on plane. but they are the fastest top end i think for my boat. 64.9mph gps at 4600rpm.

if your 23's aren't slipping too much, then going to a 4 blade may just waste energy turing the extra blade through the water, thus loosing top speed potential. it they are slipping excessively, then your boat may need the extra blade surface of a 4 th blade in the water to move your boat at the speed and rpm you want.

like Darin said. rpm and speed info is critical to determine where you stand and what is the best fix.

Rambunctious

F1campion

Darin-
I am going to pick up a new/used 25P three blade but would like you to lab and cup my 23P except do not add pitch. My stay in Washington is limited to one year and I will be moving back to Utah's high elevation within the next 5 months. I do not want any pitch because my RPM's are ok at Utah's elevation, but labbing and cupping will help remove all or most vibration and keep the prop hooked up respectively.

Rambunctious-

Its always a trade off! Unfortunately it always seems to come down to top speed. When a 28' Nordic running a whippled 502 and IMCO-mod drive pulls up next to you thinking they are the **** or a 26 commander with a bulldog motor is starring you down it is nice having the three blade to blow both their doors off even though your wife is yelling at you to slow down. I am going to stick with the 3 blade. Thank god I was tied up drinking beer when the HTM hit the water to ruin everyone else's day.

Thanks for everyone's reply!