Another prop question: Please be patiant with me - Maxum Boat Owners Club

timpyron1980 · 07-06-2011, 03:34 PM

Hello, for starters i have a '99 Maxum 1800sr with the old faithful 3.0 merc. I have owned the boat for a year now and have enjoyed it. Since ownership, the tach has never worked (needle stuck on 6k- never moves) so i have never known where my rpm's are at WOT. My speed is around 40-42 when lightly loaded. The boat is equipped with a Michigan 14x19 aluminum prop which seems to pull the boat around pretty well. My problem is my prop got damaged last weekend due to some rocks (2 blades are chipped pretty severe). I have sent my tach off to Faria for repairs so that problem has been solved but now i really dont have a good starting point to get another prop. Would it hurt to run this broken prop just enough to see where my WOT is? I would like to try a 4 blade for the better hole shot being we do a lot of tubing,wakeboarding,etc....but have no idea what direction to go on pitch. Anyone know of a company that offers demo props for trial and error? Do most 3.0's in like size boats perform in similar ways so i can get an idea for a correct replacement prop? I know the questions i am asking will come with vague answers due to not knowing WOT but hopefully someone else has encountered this before. Thanks for any answers in advance.

Brianm · 07-06-2011, 05:59 PM

I am by no means an expert but I would think that using the "damaged" prop, when you have a working tach, would likely NOT give you an accurate reading on the WOT range. You might consider having a shop look at the prop and repair it, then test it with the new tach and go from there. In other words, I wouldn't want to base my decision on how the prop / engine are preforming when one (the prop) is damaged. Can tell you that my 1900SR3 with the V6 came with a 14x23 3 blade and with light load I reached about 4700 RPM and 52mph GPS. So, it is propped right for high end speed performance. I did buy a 4 bladed 14.25X19 Solas (recommended by my tech) for "power" use (when yanking my football player sized adult sons up on skis) and it does help with hole shot, staying on plane and I lost only a little of top end speed. I do have to watch the RPM though when using the 4 bladed prop with a light load. Hope this helps and good luck.

TBarCYa · 07-06-2011, 06:31 PM

Where are you from? I have a stainless 21P 4 blade prop sitting in my shed that I'd let you try if you're from the NJ/Philadelphia area. I'm going to guess that your boat is similar in weight to mine and the 14x19 is what came on mine as well and the boat performed very well with it.

I would suggest looking for a prop shop in your area and see what they'll charge to repair it. It'll be cheaper than a new prop and if you end up getting a different prop anyway because your WOT rpm isn't right, you can keep it as a spare.

seapuppy · 07-06-2011, 07:00 PM

2 very good answers...

Bottom line is the prop is damaged and should be repaired or replaced....what is happening, that you probably don't feel, is the damage has caused the prop to slightly out of balance....it needs to be repaired ASAP...once repaired...the hull clean..lightly loaded..then and only then make your wot run with a working tach.....then you can adjust with a different prop for the performance your looking for...

second...an out of balance prop will prematurely wear the seals out causing leaking drive oil..... water intrusion..etc....

SP

timpyron1980 · 07-07-2011, 01:42 AM

Thanks for the responses, i am in Mississippi Tom so not quite in your area but thanks for the offer. I appreciate everyone's time knowing my situation is somewhat of a guessing game. I live in a lake town but no marine shop nearby- go figure..lol, i have sent several emails to different prop companies and awaiting responses. Thanks again..................Tim

timpyron1980 · 07-07-2011, 02:22 AM

Quote:

Originally Posted by TBarCYa

Where are you from? I have a stainless 21P 4 blade prop sitting in my shed that I'd let you try if you're from the NJ/Philadelphia area. I'm going to guess that your boat is similar in weight to mine and the 14x19 is what came on mine as well and the boat performed very well with it.

I would suggest looking for a prop shop in your area and see what they'll charge to repair it. It'll be cheaper than a new prop and if you end up getting a different prop anyway because your WOT rpm isn't right, you can keep it as a spare.

Tom, how did the 21 4 blade perform on your boat out of curiosity.

TBarCYa · 07-07-2011, 12:14 PM

I'm really happy with it. In fact, I got a great deal on two of them and have been running one while the other sits in the shed. The hole-shot is really good with the 4 blades and I have no problem pulling the tube around with up to 400lbs on it and two adults in the boat. At the top end, I could use a little more since the WOT rpm can be pushed past 4800rpm with a light load and little wind and she tops out at about 44mph. I'm actually trying to find someone that wants to trade a 23p for the spare 21 so I can try it.

The one thing I do notice and I'm not sure if it's because I have one of those hydrofoils on the drive or not, is that the prop does tend to lose grip on the water near the top end when fully trimmed and if trimmed out around a turn. I'm thinking I could pick up a couple mph if I could trim it all the way out and keep the prop in the water but I want to try the 23P prop first and see if that makes a difference. I considered removing the hydrofoil, but I remember the reason I put it on was because the bow wasn't coming down fast enough and it stays down now.

timpyron1980 · 07-13-2011, 02:23 AM

Small update to this but more of another question. Tach came in and i installed, the needle rotates all the way around while engine is cranking but quits registering once engine is running. Any ideas? I have my pole switch on back set to 1 being a 4 cylinder. Old tach would never move, just stuck on 6k rpm's. Went with a 14 1/4x21 Turning Point Legacy prop after playing around with several of these online "prop wiz" programs. Hope to have some results this weekend.