Pontoon Boat & Deck Boat Forum

Has anyone heard of the black max 77340cp1 pontoon specific prop. I called mercury and spoke with a tech, and he said that this was the prop I need on my boat. it is a 2007 bentley, 90hp merc fourstroke 240 cruise (24'). it had a 13.5 x 15pitch on it and would run 27-28 mph @ 5500 rpm. prop got dings around the edge causing it to cavitate,wich leads to ventillation wich slowed it down to 22 mph @ 5400 rpm. the tech said I should be turning this engine 5700-5800 rpm for max performance, and that it was designed to run 6000 rpm all day long. it does have a rev limiter, so I'm not worried about over reving it, but I just wonder how many rpms I'll pick up going to a 14"diameter x 13" pitch "pontoon prop".
this "pontoon prop" is supposed to be extra cupped to help grab more water for better traction

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Welcome

Surprised you were getting 28mph with the 90. Not familiar with this specific prop but think the 13 would be about right. The extra cup will help on the hole shot and in turns but may not give you the best top end. It sure looks like the one to try, saw some 120 to 140 buck price on the low end. Sure it would work and even make a good spare if you decided to change later on. Found this on I boats
http://forums.iboats.com/showthread.php?t=232838
Typically you gain about 200 to 300 rpm for each inch pitch you go down, given the props are similar.
Thinking between 11 on the low to 13p on the high, would be my guess. Good Luck and Welcome
doc

doc, thanks for the link, sounds like it's going to be the right prop. btw, how do you like your bentley. I wish I had the side strakes, some one should invent some aftermarket bolt on ones. it's a shame bentley went out of buisness, there should be a law, if a someone goes out of buisness, you shouldn't have to make anymore payments on their products. Oh well. lesson learned. I'll let you know how the new prop does. thanks again

For sure, would be interested in knowing how it works for you. Heard a lot of input from people using the cupped prop and they said it worked great for them. Bentley is back with the previous owner that sold the company. You can order a new bentley now. Not sure what that does to the warranty situation. Had heard he would honor the warranty on the boats he had built and not the ones that were built during the time he didn't own the company, not sure if that is true or what has happened recently. I really like my 243, lot of boat for the price. If you get in the market for one let me know got a close friend in the business, with the lowest prices in the Southeast.
Good Luck with the prop.
doc

hey doc, just took the boat out with the new prop. I'm not overwhelmed, but I am happy with it's performance. here are my results. today the lake was fairly choppy, and it was pretty windy out as storms were blowing in here in charlotte nc. I had 2 adults and 4 kids, this includes myself, and 1/2 tank of fuel and all of my gear. the motor turned 5600 rpm, and it ran 25-26 mph. not bad considering the load and weather conditions and also the fact that it is a larger diameter prop. I could really tell a difference when turning sharp, rpms didn't fall off near as much as they used too, and when pulling into the dock and onto the trailer, it seemed to be more stable and responsive. it was raining hard when loading as well. Also the boat has a hell of a holeshot now, jumps up on plane very quickly, and it will cruise 12mph @ 4000 rpm, and 20mph @4900 rpm. anyway, I think it's going to work just fine for my purpose. if the water was calm, and there was no wind, I believe I could've gotten 27 mph and 57-5800 rpm with the load I had today. I'll post further results later after I pull the tube, and when I have a lighter load and better conditions!

Thanks for the info.....I'm going to order mine in a few days....its the 14X10 version for my 6o 4 stroke. Hopefully i will be happy with it.

specialk wrote: hey doc, just took the boat out with the new prop. I'm not overwhelmed, but I am happy with it's performance. here are my results. today the lake was fairly choppy, and it was pretty windy out as storms were blowing in here in charlotte nc. I had 2 adults and 4 kids, this includes myself, and 1/2 tank of fuel and all of my gear. the motor turned 5600 rpm, and it ran 25-26 mph. not bad considering the load and weather conditions and also the fact that it is a larger diameter prop. I could really tell a difference when turning sharp, rpms didn't fall off near as much as they used too, and when pulling into the dock and onto the trailer, it seemed to be more stable and responsive. it was raining hard when loading as well. Also the boat has a hell of a holeshot now, jumps up on plane very quickly, and it will cruise 12mph @ 4000 rpm, and 20mph @4900 rpm. anyway, I think it's going to work just fine for my purpose. if the water was calm, and there was no wind, I believe I could've gotten 27 mph and 57-5800 rpm with the load I had today. I'll post further results later after I pull the tube, and when I have a lighter load and better conditions!

Thanks for posting the results. Always interested with prop results. Considering your load and conditions, sounds like it is a keeper.
doc

mjlyn wrote:Thanks for the info.....I'm going to order mine in a few days....its the 14X10 version for my 6o 4 stroke. Hopefully i will be happy with it.

mjlyn, I think you'll be happy with it, I probably could've went with a 14 x 12, but 14x13 seems to work well. 14 x 10 or 11 should work good for your's. my logs are 26" wich from what I understand helps out with speed. not sure what you have, but the 14 x 10 should work well enough for you! compared to the 13.5 x 15 I had on there, this 14 incher looks huge!