PDA

View Full Version : 1999 sweet 16 prop



hyperlite98
07-05-2004, 10:49 PM
I'm new to this, hoping someone can help me out! Just purchased a 1999 sweet 16 (1+3) with the 4.3L (190HP) alpha outdrive, came with a 19P aluminum propellar and I want to swap it out for a stainless. My RPM's with the 19P are a little high too (4900-5000) and I'm only gettin 50mph out of it.

Also during my 4 hour "test drive" last weekend i noticed she'll bounce on the water a lot with 4 people... any suggestions to keep her stable?

cheers,

jeff

MOP
07-05-2004, 11:46 PM
I can't help with the prop you need input from one of the 4.3 guys. If you don't have trim tabs get them the 16 needs them more than any other Donzi. The do nothing for speed but makes the boat handle much better, that was the best addition I made to mine. It does away with porpoising and helps a lot to trim in rough water, they also do away with the wandering a deep V does at slow speeds which is great in tight places.

Phil

hyperlite98
07-06-2004, 10:03 AM
Hi Phil, thanks for the suggestion... could you tell me what size you have on your 16? maybe what a good brand name is for the donzi?

thanks,
jeff

Sam
07-06-2004, 10:52 AM
I have either 8" or 9" tabs on my 16, they work great. Did you play with the trim on your drive, it should help if you trim it in a bit.

Sam

hyperlite98
07-06-2004, 11:12 AM
Hey Sam,

I had the trim all the way down, still porpoising with 4 people in the boat.

thx, jeff

MOP
07-06-2004, 11:23 AM
I had the 12 wide by 9 deep Bennets, there are several posts on getting them mounted right.

Phil

chip w
07-06-2004, 06:00 PM
Jeff,
When I bought my 16 the drive stop was not at it's lowest setting, thus the drive would not go all the way down causing the boat to porpise. Check to make sure that your drive is set to the lowest stop. This cured my problem without trim tabs. BTW, mine is a '69 w/302 Ford, so there's a little more weight in the back than the 4.3

Chip

smokediver
07-06-2004, 10:55 PM
welcome aboard . I have a 1998 w/ the same set up . I don't know what drive ratio you have . I have a 1.8 and I ran a 23 before going to a 4bbl. setup . If you have a 1.62 you might want to ask around who has the same ratio as you . The best 500 bucks you can spend is switching over to a 4 bbl. if you aren't fuel injected . I picked up almost 5 mph . oh, get trim tabs . world of difference in the ride quality .

hyperlite98
07-08-2004, 10:47 AM
Hi,

Yeah I have the 1.62 ratio, I talked to Donzi and they suggested a Vegeance or Laser2 14x19. Moving to a 4bbl... is there any other modifications that need to be done besides the carb?

Chip! Can ya tell me how to check that my outdrive is at the lowest setting? I have the Alpha one drive.

thanks all, this forum has been great in getting my 16 "up to speed"

jeff

smokediver
07-08-2004, 03:50 PM
You will need a new intake mainfold , carb , and fuel line . Not a hard job at all . I went with a cast iron intake as I am always in saltwater . edelbrock 600 cfm marine carb with there re-jetting kit for the 4.3 . edelbrock makes an aluminium intake for the vortec 4.3 . if I were in fresh water that is what I would have got .

MOP
07-08-2004, 04:47 PM
Jeff your Merc drive has different (no pin) setup than Chip has, pretty he is runnig a Volvo.

CrackerJack
07-09-2004, 03:38 PM
Take a look at the Lenco trim tabs. They were easy to install and work great. I had the same set up as you have for an engine and the tabs did cure the porpoising. To date they outlasted my engine.