2001 1900 Maxum Power Issue?

[jaycozer]

I submitted this topic this morning in the prop forum. I did not see the this repair category so I thought maybe some of you guys could take a crack at this also. Sorry for doubling up in forums but I'm just getting familiar with the website.

Greetings,

Our family, excitedly, bought our first boat. It was used w/120 hours on it and the previous owner really seemed tedious about the upkeep. It has a merc 5.0 220hp running a high five ss 23 pitch prop(1.47 gear ratio). When I got it the high five had three of the vent plugs removed(supposed to increase hole shot). I am 215 pound slalom skier so I expected the engine performance to get me going pretty easily. Some other lighter skiers and myself found it really sluggish first couple trips out. I plugged the holes on the prop and this did improve the sluggish starts and it planes quicker(more solid water I presume). However, with only a regular five person load(2 small kids inc.) it still holds at around 3900 rpm and tops around 40 mph WOT. It does not seem to be misfiring and feels strong throughout a session on the lake but these numbers are really off what they should be.
When I bought it the owner said he had only used 91 octane and never had any problems. It had sat several months(previous owner had a severe injury) before I bought it so I have been filling it with 91 each trip out and trying to run it as much as I can. I feel if I keep running it at this low rpm the plugs may foul, if they haven't already. I also don't know if the 23 pitch would have this much effect on the performance with such a normal load.
At any rate, before I take it in to the local shop if anyone could give me some direction on performance or mechanical solutions I would appreciate it.

Thanks for reading a novel from a newbie!

 

[JoJoBetsy]

Re: 2001 1900 Maxum Power Issue?

Let's start with the engine and prop serial numbers and outdrive type. My initial thought is you have a prop/engine mismatch, i.e. overpropped. Hole shot props are 17 and 19 pitch. A 23P five blader seems like a lot of prop for a 5.0L/220 HP motor. You should have 4400 to 4800 RPM at WOT with a 19P three blader.

Let's not forget as well that unless the previous owner had receipts for the last engine tune-up(s) you should probably look into doing most of this now so that these "basics" can be ruled out.

jb

Here's what Merc says about their PVS props. I have one and my holes are plugged up.

The Performance Vent System (PVS) was created to help our customers optimize Mercury Propellers on their personal boat and unique boating conditions. PVS allows the boater to "custom tune" the venting of the propeller blades to dial in the perfect acceleration and cruising performance. On acceleration, exhaust is drawn out of the vent hole located behind each propeller blade. When the next propeller blade strikes the aerated water, less force is required to push through the aerated water vs. solid water. This allows the engine RPM to rise more rapidly. Once the "on-plane" speed has been reached, water flowing over the vent holes seals the exhaust in, allowing the propeller to again operate in solid, non-aerated water. By varying the size of the exhaust hole, the rate at which the engine RPM rises can now be controlled. Laser II, Trophy Plus, and Tempest Plus are shipped with the medium PVS vent plugs. Mirage Plus, Offshore, Revolution 4, and High Five are shipped with the Solid PVS plugs. Most acceleration problems can now be addresses, Some examples are: Slow/Sluggish acceleration to plane (engine unable to push solid water away quickly) Over ventilation - the propeller breaks loose allowing the engine to over-rev before reaching plane (there is too much air being drawn into the propeller blades).

 

[paulie0735]

Re: 2001 1900 Maxum Power Issue?

Your boat / engine package is never going be a stellar performer as a ski boat. 220hp is the peak reading, the 5.0 was never a big torque deliverer at low rpm. As a ski boat these would have been fitted with the 5.7 magnum. Also worth considering is that many owners who 'don't know better' fit bigger props to get the rpm down thinking they are saving on fuel. Truth is they are probably using more because the engine is always working harder. Sounds like all is fairy well with the boat and engine, what you need is some test props to get the hole shot your looking for. At 215lbs you’re no light weight so you may even consider a set of smart tabs but get it propped right first. For sking I would prop it for 4800 - 5000 at WOT. Top speed should be around the mid 40’s. Good luck.

 

[fredster]

Re: 2001 1900 Maxum Power Issue?

I have a Larson Senza 186 with the 220 merc/alpha 1.68 ratio. The stock prop was a 21 pitch/14.25 incher which is 2 less pitch then yours. I then switched to a MI Wheel Avenger 4-blade stainless, 20 pitch/14 incher. This really improved my holeshot and reduced planing speed from 18 to roughly 15, less bow lift, too. My top speed is the same or slightly higher (51.5-52MPH).

To do it over I would have used a 19 as I am only turning 4500 WOT and could go up 2-300 RPM's and still be in the range on the top end but gain some grunt on the bottom. If you try something with a pitch of 18-19 I think you will be a lot happier.

 

[Crownie2]

Re: 2001 1900 Maxum Power Issue?

I agree with the guys above. In my experience it is a very rare family I/O that can pull a 23" prop.

You need to beg, borrow or... well, try a 19" prop somehow to see what it will do for you. Then you will better know how to spend your money.

P.S. the new Enertia prop from Merc does just about everything well but is expensive...

 

[Bondo]

Re: 2001 1900 Maxum Power Issue?

Ayuh,......... I Agree,...........

It sounds like you're Both,... Over Propped,+ Over Loaded.......

When you want to Ski,....... Drop off some of the Extra People in the boat..........

 

[John_S]

Re: 2001 1900 Maxum Power Issue?

As others have said, you are over-proped. A 305 in a 19' bowrider should be great for family water sports. As Paulie suggests, look into smart tabs. That 305 probably makes that stern set low. I would suggest adding the tabs before dialing in the prop. Also, since you might migrate to wake boarding, consider the trolling brackets which will allow you to create a good wake, when you want it.

Hopefully you will find a place that will allow trying out props. If not, start with a 19 pitch aluminum, and work from there.

 

[jaycozer]

Re: 2001 1900 Maxum Power Issue?

Thanks for all the input so far. This information has helped this new boater look for possible tweaks in my setup and takes away some worries about performance issues. The engine does start, stop, and run solid so these tips could help greatly.