Prop or Speed issues.....

Mastiff Rider64

New Member
May 16, 2016
9
Spartanburg
Boat Info
2002 Sea Ray 200BR
Engines
305 or 5.0 MPI Mercruiser with Alpha 1 drive
Hi, looking for some advice on how to fix an issue I'm having. I have a 2002 Sea Ray 200BR with a 5.0 MPI, Alpha 1 that I believed to be geared at 1.47:1 or maybe 1.62:1. But here is my issue, I had a 3 blade SS prop 14x19p on it. WOT (rpm's) would reach over 5000 to the point the rev limiter would shut the boat off, top speed GPS tracked was 40 MPH. This was with 2 adults, 1 child, ice and drinks in the cooler made into the passenger dash. After months of the boat cutting off I decided to change props. I bought a revolution 4, 14-5/8x20p. Now my WOT (RPM's) are about 4200 and top speed GPS tracked was 42 MPH with the same load out. I'm wondering since everything I read told me to go up on pitch size since I was over revving the motor, how now I can't reach desired rpm's of 4400 to 4800. And why my top speed only increased by 2 MPH with a 4 blade prop. And what really troubles me is how I keep reading all these ppl with boats either the same as mine or close to mine, either older or just a few years newer running 50 plus MPH. What should I check to get mine to run that fast? What prop works best, cause 3 blade 14x19p doesn't work with my set up, and 14-5/8x20p keeps the boat from cutting off but won't reach desired rpm's. I worry that a 14-5/8x19p may let the high rpm's back and if a 20p only got me 2 MPH faster does that mean I will lose that going back to a 19p? Any advice would be grateful, or any answers as to why my boat is stuck in the 40 MPH range when others are busting 50 plus.
 
Just my opinion, but you did 2 steps at once. I would of gone to a 3 blade prop 1 pitch higher, or a 4blade that is the same pitch.

I think the engine with the extra blade and higher pitch was too much
 
A four blade prop reduces slippage, like 4 wheel drive on a vehicle. The penalty is increased drag on the top end. Great for water sports like pulling slalom skiers. You were very close with the original prop and more people on board.
 
Something doesn’t seem right. my 240 sundancer with a 5.0 fully loaded with 6 people will do 43-44 mph gps at 4600-4800 rpm. And my boat is much heavier than yours.
 
What doesn't make sense is the loss of over 800 RPM's simply by going from a 19" 3-blade to a 20" 4-blade. There's something else going on here to explain that. That is way to big of a jump to be explained by just the small difference in props. And, yes, upper 40's to low 50's is about right for that model.

Also, the 40MPH (even with the 19") doesn't seem right. It really seems like something else is going on here. Whether it's a mechanical/engine issue... dirty bottom... not trimming properly... there is definitely more going on than just a prop issue.

Most likely, your boat came standard from the factory with a 21" Vengeance SS prop. Go to Sea Ray's website and look at the prop matrix to double check me, though. But I still highly doubt that putting the OEM prop on there is going to solve this.
 
Something doesn’t seem right. my 240 sundancer with a 5.0 fully loaded with 6 people will do 43-44 mph gps at 4600-4800 rpm. And my boat is much heavier than yours.
Exactly part of my point. I recently found that my boat came with a 13.75x21p 3 blade mercury vantage prop. And sea ray says my boat will do 55 mph with that prop atleast everything I've seen in the old brochures says top speed 55 mph. But I cant break 42 mph on the best day with a calm water. I've had the 13.75x21p on there it was topping out at 44 mph, went to a 14x19p to increase hole shot without giving up to much top end, that prop dropped my speed to 39 to 40 mph and over revving the motor. so I go to a 4 blade 14-5/8x20p and I'm back to 42 mph, not the best hole shot. I have the revolution 4 with VPS system with small hole plugs in. So going to a 4 blade I gained top end which is never heard of and I also increased diameter and pitch but lost my rpm's. So what gives?
 
You have other issues besides the prop. your engine is probably tired. Tune up, compression , fuel pressure ?
 
Exactly part of my point. I recently found that my boat came with a 13.75x21p 3 blade mercury vantage prop. And sea ray says my boat will do 55 mph with that prop atleast everything I've seen in the old brochures says top speed 55 mph. But I cant break 42 mph on the best day with a calm water. I've had the 13.75x21p on there it was topping out at 44 mph, went to a 14x19p to increase hole shot without giving up to much top end, that prop dropped my speed to 39 to 40 mph and over revving the motor. so I go to a 4 blade 14-5/8x20p and I'm back to 42 mph, not the best hole shot. I have the revolution 4 with VPS system with small hole plugs in. So going to a 4 blade I gained top end which is never heard of and I also increased diameter and pitch but lost my rpm's. So what gives?

Vengeance, not Vantage.

What brochure did you see Sea Ray stating it would do 55mph? I have never seen Sea Ray state speed numbers in public brochures. In fact, they typically refrain from publishing anything like that on purpose. Dealer info states 49-53. Which is right in line with what I remember. Maybe there is something (public) out there, somewhere?

You gained some speed with 4-blade 20p because you went up in pitch from the 3-blade 19p.

You've got to get off the prop thing as the issue - you're chasing the wrong culprit. As mentioned, unless it's the way you're trimming it, it's a mechanical/fuel issue.

It's a little confusing trying to follow what you're saying, at times. For example: "But I cant break 42 mph on the best day with a calm water. I've had the 13.75x21p on there it was topping out at 44 mph"
 
Sorry to confuse you, 42 mph (gauge on dash) with the 3 blade 19p factory black one. The 3 blade SS was 40 (GPS), then the 4 blade 21p was 44 mph(gps). Now i have the Hi Five 5 blade on it and lucky to get 40 mph(gauge on dash). And I do have some issues for sure ever since buying the boat. If I run wide open throttle and get to 4400 to 4800 RPM and run it there for any length of time the boat just dies. like running WOT to nothing, motor dies and you have to cut key switch off then back on, crank the boat and it will run fine again until you go WOT again. Then it will die again, no warning bells no nothing just dies. I've spent well over $3,000 chasing two rabbits down holes at 3 different boat shops, the last place just told me not to run it at WOT and problem solved, but charged me $500 in labor for trying to track down the problem. Another problem I'm having is I can run the boat for hours at 3/4 throttle to just no waking it around the lake. But get to a sandbar and spend a few hours there and get back in the boat to leave and it wont start or if it does it seems to starve for fuel and cuts off. I have spent over an hour drifting down the lake trying to start my boat. This weekend I actually took video of this issue because those 3 boat shops said they couldn't get it to repeat the issue. Even tho they replaced fuel pump, even said they added a secondary fuel pump called a booster pump because my boat calls for that, even tho I cant seem to find the secondary one???? The shops have replaced idle air sensor, fuel injectors, crankshaft position sensor, map sensor, air filter, water separator filter, ignition coil, rotary button, distributor cap and wires, but issue is still there. Which it isn't an every time issue. Some time and most the time the boat starts right up, every once and a while after running the boat for long periods of time it just wont start back up. I noticed this past weekend also cranking the boat and just sitting at idle that the tach gauge will go from about 800 rpm to about 3000 rpm at a slow climb, then back down to 800, then to 1000 back down. now once i give it throttle it stops but still shouldn't be doing that. If you would like to see the videos of what the boat is doing I'll gladly email them to anyone who has an idea what to check. for some reason it wont let me upload them to this site.
 
Last edited:
What's your fuel pressure doing at WOT when it dies?
I honestly don't know. I've taken it to shops and they tell me that they can't get it to repeat the same issue. Yet I can put the boat in the water right after getting it back and I can get it to cut off within minutes. I'm not sure how to check the fuel pressure on the boat, as I'm driving it and getting it to cut off. I mean boat is running fine somewhere between 4600 and 5000 rpm and then boom it just dies. Cut the key off, turn it back on and it starts up every time. I've gotten so use to it that when I feel the boat die I throw it in neutral cut switch off and back on before the boat slows down to much. But I was hoping to fix these issues over the winter, as I have pulled my boat out for the year now.
 
On my engine it’s a little difficult to check fuel pressure while running. It’s under the plenum, I would need to extend the Schrader valve.

It May be worth installing a gateway to see the fuel pressure on your phone. I installed a fox marine gateway, love it. My engines are not smartcraft, but gives me so much data, well worth it. There is other brands out there. You would need to find out which one for yours, mine took a mefi-3

https://fox-marine.com/index.php?route=product/category&path=81
 

Forum statistics

Threads
112,950
Messages
1,422,860
Members
60,932
Latest member
juliediane
Back
Top