Prop Size
 

Hello to all!
I am new to the Forum due to the recent purchase of a 2000 Mariah 202 Shabah with a 5.0L Mercruiser with Alpha 1 GenII outdrive. The boat is in great shape with new interior with 197 hours on the motor. I have all repair records and it appears the impellor has not been serviced and during inspection of the boat I noticed the exhaust bellow is torn on the outdrive end and the cable boot has a hole in it from age/wear.
The top boot in which the ujoint is located in still good and boot is not hard and cracked. It was replaced in 2005 with the boat not used much since then. So I have some service work to do on this outdrive as I anticipated.
The first question I have is the Prop! I want to replace it and when I pulled the prop off the boat and tried to locate the size and pitch but could not find any numbers. The local marina parts store could not determine which one I would need.
What is the prop size for this boat? I want to pull towables and the occasional skier.
Second question: I have always had outboard motors. The tear in the exhaust bellow and cable boot scares me. Will that tear in either boots let water into my boat and flood it while I'm out for the day on the lake. I assume the cable boot would let water in but unsure about the exhaust boot.
Thanks for the help! Peter

Re: Prop Size
 

Yes the bellows should be replaced and that means removing the outdrive and you should replace the impeller while you're at it. Before you remove the outdrive though, check to see if your trim gauge is working properly because that's a common problem. If not & a simple servicing of the trim switch doesn't fix it, you have to remove the outdrive to replace it.

As for the prop, likely a 19" pitch will be a good place to start as that was the stock size prop for this engine. It will provide a good mix of grunt & medium range speed.

Re: Prop Size
 

Thanks Mike.
I will definetly have the pump and impellor replaced.

You said 19" pitch, do you know what size 13, 14, 14.5 x 19?

Hopefully I can get my boat in for the repairs, the season starts Memorial Day weekend and the shops are busy. I was ASE certified mechanic(cars)way back and saw some U-Tube vidoes on changing the pump/impellor and it appears to be easy. I don't have the tools to do the hoses and if I cannot get it into a shop soon, I might try to replace the pump/ impellor myself with a buddy until I can get it into the shop.
Thats why I asked about water getting into the boat from the exhaust bellow and the hole in the cable boot. Will I sink if I go out and hang out for the day and keeping an eye on it while using the bilge pump when needed???
I saw these exhaust tubes as replacements for the bellows but they don't appear to connect connect to the outer part until the stern drops down. I'm curiuos on how does that not fill up the boat with water when sitting.
This is our first inboard/stern drive set up. We have been pontoon boat owners for 15 yrs and the kids are grown up now and want to ski, ride water tubes and wakeboard. I felt an inboard was a better choice for the sport activities and was tired of listening to the 2 cycle outboard.
Peter

Re: Prop Size
 

Anything from 14" to 14.5" x 19 should work. Ideally, finding a prop shop that will let you test run a couple of props would be best. I'd start with a 19" and check your rpm's at WOT. You shouldn't go above 4800 max at WOT.

btw...the original prop may not have shown a dia x pitch size on the back of the hub but may have shown a part# instead. If you can find that we can tell you what prop it is.

I wouldn't screw around with the bellows etc. You do run the risk of water entering the boat and also causing damage to the gimbal bearing & outdrive. Fix it properly & ignore the aftermarket gimmicks and then you will have nothing to worry about out on the water.

Re: Prop Size
 

The old prop has corrosion around parts of it. Cannot find any numbers. Will have to take a chance on the one you have recommended. Thanks for the help. I like the pictue of your boat with the bimini cover's side walls and front cover. Where do I find this? We sometime get afternoon down pours for 10-15 minutes and it would be nice to enclose the cockpit area.
I will find a professional to uodate the outdrive with bellows, seals, pump/impellor and take a look at the trim sensors.
Thanks for the advice!

Re: Prop Size
 

I had my bimini top & side covers custom made by a local marine canvas shop. It's always slightly more pricey to go custom but you are guaranteed a perfect fit that way.

Re: Prop Size
 

Hi Boaters

Well had no luck with the marine stores. They have 19" pitch props, but what size diameter.
13", 14", 14.5" x 19.

Does anyone else out there know exactly what prop they have on their 2000 Mariah 202-5.0L?
I have looked at the prop charts available and there are several sizes available listed for this 5.0L-Alpha1 outdrive which does me no good. I don't have the time to experiment on which one is the best, I just want to know who has an stock aluminum prop number for this boat and/or might know which size stainless steel available.
I just want to get a prop on this boat by this weekend and start having fun! Not looking for speed as much as towing the towables and skier.

Thanks,
Peter

Re: Prop Size
 

Your boat isn't unique so a correct prop that will give you the results you are looking for should be easy to locate as per my earlier suggestions.

Here's a link to iboats.com prop page for 19" props for your engine. Lots of choices and most should be available at any local prop shop / marina / boating store if needed by Friday.

Re: Prop Size
 

I was under the impression that when these boats were made, the boat manufacturer had a specific(through R&D) size and pitch prop that complimented this particular boat hull made for Mariah and that the manufacturer did not just put different sizes on the same boat.
Unless these boats are delivered without props to the dealerships and the dealer has to select whatever they think is correct.
As you said " your boat is not unique" so there should be quit a few out there. I was hoping someone on the dock here replaced their original prop on the same boat, same year, same model and remembered the specs on it or maybe what they replaced it with.
It appears that the 4 blades are good for the towables and skiers. I'm not concerned with speed.
Thanks for the link.
Peter

Re: Prop Size
 

Yes & no to the standard prop question. The mfr would install what prop worked best in most situations and for most of our boats in the 18-22' range that meant a 3 blade 19" prop. Buyers would sometimes change them out on purchase for something more suited to their needs (speed/cruising or pulling tubers/skiiers etc) and some dealers would give you a choice of 2 or 3 different props to install on your new boat. Also, dont get too concerned about diameter but stay in the 14 - 14.5" range. Going larger than that creates extra drag and possibly even contact with the cavitation plate while going smaller means less push and more work for your prop to get the same results.

As for 4 blades vs 3 blades, yes 4 blades performs better when you are pulling things. That 4 blade gives you a little extra 'bite' at low/mid speeds at the cost of 2-3mph top end off a similar size 3 blade prop. I do mostly mid speed cruising of the islands in Georgian Bay and haul my teen around on his wakeboard so I currently run a 4 blade SS - 20" prop on mine which performs very similar (but with slightly more grip) compared to the 3 blade 19" i had on the boat originally. I also have a 19" and 21" - 3 blade aluminums as spares. Going any farther (ie 17" or 23") starts to cause problems. Over propping and under propping a boat puts considerable stress on your engine whether you are running at high speed or not. That's why its important to stay within the recommended rpm range for your engine.

Best of luck with your choice!