polaris7541 Posted June 25, 2023 Share Posted June 25, 2023 bought this boat used , pretty sure its a frankenstein ,92 4 wwynns 205 prop that was on it is a 14.5 x19 pitch,, original prop is to be a 14/ 1/4 x 19 pitch , at 3500 rpms . almost wfo . i can get 35 gps mph,, should i go with a 14/14 x19 or 14 /1/4 x 21 any help would be great ,, it does take a long time to plane out ,, motor is a target 5.0 has 80 hours on it seems to run ok Quote Link to comment Share on other sites More sharing options...
Guest Posted June 25, 2023 Share Posted June 25, 2023 What is your target peak rpm? 21 will lower rpm and take longer to plane out. Quote Link to comment Share on other sites More sharing options...
polaris7541 Posted June 25, 2023 Author Share Posted June 25, 2023 boats is to hit 4000 too 4500 rpms , most i can get is 3800 with the 14 ,5 x 19 pitch checked with 4 wynns they say it should be a 14 1/4 x 19 pitch the 14.5 is what came on the boat the spare prop i have is a 14 1/4 x 21 pitch , so im thinking i should get a 14 1/4 x 19 then Quote Link to comment Share on other sites More sharing options...
Guest Posted June 25, 2023 Share Posted June 25, 2023 1/4" less prop isn't going to net you 500-1000 rpm. Someone on here must have more experience than me but IMHO you should be running a 17 pitch prop. Will get out of the hole better and gain rpm. Heck you may need a 15 pitch. My boat runs a 13 3/4 X 15 and a buddy wanted me to try his 19 pitch and my boat couldn't get out of it's own way. Quote Link to comment Share on other sites More sharing options...
favoritos Posted June 25, 2023 Share Posted June 25, 2023 The 1/4" won't make that big a difference if they are the same cupped blades. It does make a difference if you are SS and cupped tips. The older aluminum blades tended to flex and people added pitch to try and cheat top end. There are a lot of factors in a prop. Size alone isn't enough. Have you tried the 21 pitch? I wonder if it is a straight tip? I'm surprised they even had one that far out and kept it around. I bet that would barely plane out with anything in the boat. HSR is right on track. Try less pitch. Do you have any buddies that have the same drive spline? It might be worth trying a few different props to get it running just right. Some of them may have extra props laying around. There is room to run quite a bit better with that boat. I bet a lot is just in the prop. In my boating days, I kept quite a few props laying around to "play". Holeshot, speed lock, hybrids, and plain ol fast, were changed with simple prop swaps. If that motor is running right, it sounds like you simply have too much prop. I doubt it is in the 1/4" diameter. 1 Quote Link to comment Share on other sites More sharing options...
polaris7541 Posted June 26, 2023 Author Share Posted June 26, 2023 ok if i go to a 17 pitch will that have more top end speed , from the math sounds like the rpm s will go up , i think i need to find out what the drive ratio is also , boats pretty clean ,, motors been replaced ,, it might not be marine drives been replaced as well , dose seem like all the work was done proper, , but who knows,, theres to versions of the motor ,ones 185 ponies , the other 200, that could be issue as well, thanks for the inputs Quote Link to comment Share on other sites More sharing options...
Deephaven Posted June 26, 2023 Share Posted June 26, 2023 What type of prop do you have on it now? 14.5 x 19 aluminum, ss, 3 blade, 4 etc... I am also not sure I understand your 4000-4500. Find the max and target that, you can always not use full throttle. The other question is how the motor is mounted. Set back and lifting up a motor can really change the RPM's. I don't want to assume that the 205 is either an inboard or I/O but obviously good to know as well. The other question is what is more important to you. I am running a 12.25 on my Malibu, but it leaps on plane even with 6000lbs of ballast and 8 people on board. I have 4 different props for my fishing boat depending on the water I am going to run but generally prefer reasonable midrange to top end. Quote Link to comment Share on other sites More sharing options...
polaris7541 Posted June 26, 2023 Author Share Posted June 26, 2023 yep prop that came on it is a 14.5x 19 pitch 3 blade , its a 4 wynns cuddy cabin ,, 5.0 stern drive ,, 4 wynns states prop should be a 14 1/4 x 19 pitch . highest rpms i can get is 3800 on a good day at 35 mph on gps, 4 wynns states max rpms should be 4000 / 4500,, motor and drive have been replaced prior me buying the boat , only has 75 hours on motor , problem is there are are 2 5.0 listed for this boat mine is to be the 200 pony one , the other is 185 , not sure which one i have ,, Quote Link to comment Share on other sites More sharing options...
polaris7541 Posted June 26, 2023 Author Share Posted June 26, 2023 prop is aluminum. Quote Link to comment Share on other sites More sharing options...
Deephaven Posted June 26, 2023 Share Posted June 26, 2023 I'd guess a 14.5 x 17 would be the best starting point. It will really wake up the boat. If you don't care about top end a 16 would get you on plane faster. 1 Quote Link to comment Share on other sites More sharing options...
Deephaven Posted June 26, 2023 Share Posted June 26, 2023 1 minute ago, polaris7541 said: prop is aluminum. Assume then you are buying an aluminum replacement for the above. Quote Link to comment Share on other sites More sharing options...
polaris7541 Posted June 26, 2023 Author Share Posted June 26, 2023 need to replace the prop , hit a rock ,, just looking for improvements out of the hole and on top speed Quote Link to comment Share on other sites More sharing options...
polaris7541 Posted June 26, 2023 Author Share Posted June 26, 2023 yep aluminum Quote Link to comment Share on other sites More sharing options...
polaris7541 Posted June 26, 2023 Author Share Posted June 26, 2023 would the 17 give it higher rpms and more mph Quote Link to comment Share on other sites More sharing options...
Guest Posted June 26, 2023 Share Posted June 26, 2023 2 hours ago, polaris7541 said: would the 17 give it higher rpms and more mph Yes the closer you get to peak rpm the more hp you are making and the faster it will spin the prop. Very similar to clutching a sled. Quote Link to comment Share on other sites More sharing options...
krom Posted June 26, 2023 Share Posted June 26, 2023 (edited) Boat needs to be propped so it runs the top edge of the recommended rpm range with only the driver and a light load of fuel aboard. This will keep you in range for 99% of use conditions. too much prop will lug the engine, and burn valves, not enough and you risk throwing a rod from over revving. all things equal going from 19 to 17 is good for 200 rpm Edited June 26, 2023 by krom 2 Quote Link to comment Share on other sites More sharing options...
Deephaven Posted June 26, 2023 Share Posted June 26, 2023 I'd expect way more than 200rpm... Quote Link to comment Share on other sites More sharing options...
krom Posted June 26, 2023 Share Posted June 26, 2023 (edited) 39 minutes ago, Deephaven said: I'd expect way more than 200rpm... 200 per step on an aluminum is pretty normal, unless you are off a ton to begin with. Check the gear ratio on the outdrive, it wouldn't be the first time someone installed the wrong one.. post the transom plate serial number, and/or original engine serial number Edited June 26, 2023 by krom 1 Quote Link to comment Share on other sites More sharing options...
polaris7541 Posted June 27, 2023 Author Share Posted June 27, 2023 16 hours ago, krom said: 200 per step on an aluminum is pretty normal, unless you are off a ton to begin with. Check the gear ratio on the outdrive, it wouldn't be the first time someone installed the wrong one.. post the transom plate serial number, and/or original engine serial number gotta wait til rain stops Quote Link to comment Share on other sites More sharing options...
sleepybrew Posted June 27, 2023 Share Posted June 27, 2023 the drives also have different ratios. my boat is 20ft with a 4.3 and alpha drive, running a 23 pitch. also depends on the use. i wake board and need a good pull. my last boat i had a stainless prop repitched to a 20. gained just enough with no loss of top end from the 21 that was on it. i don't think they make even number pitch but the prop shop did a good job. a stainless prop does not flex as much and may give a better yank. i am primarily in the hudson river which has a mud bottom. lakes up north are all rock. in the river stainless is good because of debris. aluminum will get a ding quicker than shit, stainless will chop up most things and not notice Quote Link to comment Share on other sites More sharing options...
polaris7541 Posted June 28, 2023 Author Share Posted June 28, 2023 got a 17 on the way , thanks for all the input guys looked at the drive tag ser num and listed for 5.0 motor only things legible.. don't think stainless would be a good choice were my boat swims ,, to many rocks,, heard if you go stainless and hit a rock you bust the drive most of the time.. the prop i am getting is pressed cast ,which from what the guy told me dose not flex as much ,, we will see Quote Link to comment Share on other sites More sharing options...
krom Posted June 28, 2023 Share Posted June 28, 2023 4 hours ago, polaris7541 said: got a 17 on the way , thanks for all the input guys looked at the drive tag ser num and listed for 5.0 motor only things legible.. don't think stainless would be a good choice were my boat swims ,, to many rocks,, heard if you go stainless and hit a rock you bust the drive most of the time.. the prop i am getting is pressed cast ,which from what the guy told me dose not flex as much ,, we will see If you post a serial number of the original factory engine, or transom, I can run it in merc's system to tell you what gear ratio drive was on the boat when it was built. Quote Link to comment Share on other sites More sharing options...
polaris7541 Posted June 29, 2023 Author Share Posted June 29, 2023 motor and drive have been replaced ,, also its a omc,, new prop came , blades are real thick, but over all weight , is lighter than old one , worried if i hit something, ,gonna bust the drive now prop is a turning point hustler its not supposed to flex ,, i can see why Quote Link to comment Share on other sites More sharing options...
Gold Member EvilBird Posted July 2, 2023 Gold Member Share Posted July 2, 2023 On 6/29/2023 at 4:55 AM, polaris7541 said: motor and drive have been replaced ,, also its a omc,, new prop came , blades are real thick, but over all weight , is lighter than old one , worried if i hit something, ,gonna bust the drive now prop is a turning point hustler its not supposed to flex ,, i can see why 19p 3 blade is most likely what came stock on that Boat just fyi. Thats typical for that engine and size boat. 17p will get you out the hole faster for sure but I am guessing you will lose some top end speed along with gaining rpm. So just depends what you want. Personally id try a 4 blade 19p next if the 17p you just got doesn't work out. As for the prop not breaking if its aluminum dont worry it will break first. Stainless is another story. Just for reference I run 3 props for my boat depending on load etc. 21p 4 blade, 23p 4 blade , 23p 3 blade (stock) The 23p 4 blade is overall best around for MPGs, holeshot , top speed and even turning. Highest top speed the 3 blade 23p is still king by like 1-2MPH. My 21p I only use if I have full fuel, full gear and a bunch of people. Unfortunately sometimes You just gotta buy a few props to really dial it in. Ill probably end up buying another one soon enough. 1 Quote Link to comment Share on other sites More sharing options...
polaris7541 Posted July 2, 2023 Author Share Posted July 2, 2023 k getting confused is a 21 pitch faster than a 19 Quote Link to comment Share on other sites More sharing options...
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