Abdulaziz

Hello, I am new to high performance boats, I have just recently entered the game 3 months ago and have a twin staggered 525 efi engines on my Fountain. I was wondering if I could get some pointers from you guys since I see there is a lot of experienced people on here.

When running my boat the max rpms she hits is 4000-4500. I know that these engines in stock should hit 5400 rpms. Also my props size is big and I was told that its best to have smaller props. I was wondering is that the only reason or could there be something else?

Also what upgrades do you guys recommend? Note that I looking for something that is fairly safe on the engines and wouldnt cause any break downs. At the end of the day I want to take the boat out and enjoy my weekend!

Thanks any advise would be appreciated..

Gary C

Welcome to the boards. I'm sure some of the experts will chime in soon. But to help you, you need more info. What year and size is your boat? What size props are on there now? How many blades on the props? How is the hole shot now with this setup? If it is real hard to get out of the hole and you only get the tachs to 4500, then I would say you need to go down at least 5 inches in pitch. But I find that hard to believe someone would sell a boat so over propped. You could have something else going on. Lets see what someone else comes up with.

Abdulaziz

Gary thanks.

My boat is a 2006 Fountain Lightning, and the current props are 30'5 blade maximus props.

I dont understand what you mean when you say "How is the hole shot now with this setup? If it is real hard to get out of the hole and you only get the tachs to 4500, then I would say you need to go down at least 5 inches in pitch."

bear with me as I said I am kinda new to powerboats.

Thank again.

sommerfliesby

In 2006, Fountain made 42 Lightnings and 35 Lightnings...which one do you have?

Abdulaziz

Based on what I know from my 3rd party company and broker when purchasing the boat its a 2006, 38ft.

Crude Intentions

iTrader: (1)

Fountain had a 38 lightning in 06. I see lots for sale.

GoFastSonic

Try the trim button.

Abdulaziz

thats after trimming, then the engines start heating up so I take it easy on the trim...

Dave M

Your temp rises when you trim up? Sounds like you may have other issues.

You should be propping for around 5200 RPMs. Sometimes when somebody sells a boat, they throw on some props that they had laying around rather than the set that should really be on the boat.

Maximus props act like a larger prop than say a bravo. I'm on the rev limiter with a 28 Bravo, and I only see around 5000 w/ a 26 Maximus.

Abdulaziz

There could be some issues, but I see the temp raising after trimming for a while. Usually where I am from powerboat owners upgrade their cooling systems since it gets really hot over here, with outside temp hitting 122 degrees...

I have been advised to go with a 28’ 4 blade props, but would that give me more rpms?