Is 600lb Fat Sac enough for 18.5 I/O Boat?

leviwynnyk

I have a 1996 Glascon 18.5 bowrider with a mercruiser 4.3LX engine and just bought a 600lb fat sac. Will this be enough for the boat or will I need another? I already installed a Monster Tower on it because of this forum (Very solid, and better then expected), and am looking for some advice. I want the wakes as big as possible without wrecking the engine or anything.

Thanks.

ffboarder · Newbie Joined: 14 Mar 2004 Posts: 20

I have a 18.5 bowrider Four Winns with a 5.0 liter OMC Cobra. I put a 600 pound fat sack in the ski locker and if the boat is full of people, I can't get on plane. With just my family, the 600 pound sack is good. I have a 19 pitch 3 bladed prop and I am probably going to a 4 bladed lower pitch prop. (Thanks to the advice on this forum) So, my long winded answer is that with your engine, and I assume you have a similar prop to mine, a 600 pound sack should be plenty.

5280HighButter · Soul Rider Joined: 16 Mar 2005 Posts: 258 City: Littleton

I've got a 600 locker sac as well, and a 20ft 5.7L V-8, I add another 300 and people but ya the 600 will be fine, you could add more if you want but a 6 hundi will make a great diff. As for the planing issue stated above make sure you place this sac in the bow walkway area or there about, the more forward the better. Also drop to a 4 blade 17.

leviwynnyk · Posted: May 02, 2006 6:29 pm Post subject:

So the 600 LBer should be enough. I was debating getting another one, and I am just not sure if I will see or notice a big difference with the one bag. And advice for driving an I/O for a wakeboarder? This will be my first year on this boat, since I have been riding behind a 15.5 foot Tri-Hull with a 100HP outboard for the past 2. I am really hoping this newer boat with the Monster tower and a Fat Sac will be an improvement.

As for the sac, I had originally planned to put the 600 across the back of the boat but now from every one's advice, I am going to put it closer to the bow.

Vampyre · Addict Joined: 12 Oct 2004 Posts: 622 City: Ooltewah, TN

I have a 18.5 ft I/O with a 4.3L as well. Here is what I run.
600 lb sac in the bow walkway, as far forward as possible. I also have a few waterbed tubes filled with water in the ski locker, about 150 lbs. On either side of my engine I have about 50 lbs of sand in a bag. I am still running my 19" 3 blade SS prop.
I usually run with just one other person, about 160 lbs or so. The wake is OK, and has a clean spot, running at about 21 mph, just is not clean for very long along the wake.
It is a struggle to get a clean wake, but, it can be done.
So.. my answer is yes, that should be just fine, just push it up as far as possible. If I have a passenger, I usually put them in the bow as well as that fat sac.

leviwynnyk · Posted: Jun 14, 2006 10:26 pm Post subject:

Thanks for the advice. i had it in the middle of the boat, but more to the front, but I'll try it all the way in the bow. Would 1200 be too much?

Vampyre · Addict Joined: 12 Oct 2004 Posts: 622 City: Ooltewah, TN

That depends on how many people are in the boat. I have run 2 of those fat sacs in the bow (the one in the floor 600 lbs) and another laying across it, about 3/4 full. This is only with one lighter person in the boat though. Having a lower pitched, 4 or 5 blade prop will certainly help this.
I would not get greedy with the weight just yet, try the 600 in the bow, and maybe some portable weights (like a bucket of concrete) that you can move on the fly, as needed to experiment with the weight and wake