302Sport

i agree, if they can run the same boat with surface drives and get it dialed in, then i think playing with the props should solve your problem.......my prop shafts are 1" below the running surface and about 48" back from it.

Kool-Aid Man

What kinda power are you running

BLee

Just curious, but did the boat come with 5's on it when it was new? 1999 is a pretty late year model to have 5's on is the only reason I ask.

If someone added the 5's afterwards, the X dimension could be off by quite a bit if they didn't adjust for the drive change & transmissions, since TRS drives were pretty much out of production by 1999 when the boat was built.

Like others have already said, I'd try either having your props redone, or buy new ones all together if it were mine. If you have a reputable prop company do the work, they should be able to eliminate the porpose for you assuming it isn't too violent. If props don't smooth it out, try spacers next.

CIG3

You 99 with even a covergirl cabin is trying to carry alot of weight up front. With the "X" as high as it is your fighting a leverage problem. I agree with both opinions. Props will help but your "X" is a little too high. I would looks for a 2" spacer see how it runs, then send the props out. If you do the props first and the problem isn't fixed you are gonna have to get the props done again after the spacers. The only way to get the props right is to give the prop guys the correct information BBlades is great to work with.

bigfarmer

i have 2" spacers that I'am going to put in this season once the weather turns around here and stops raining every day.. my props are 17.5x29 merc 4 blades, what should i try first? (more blades, different pitch, diameter?) Also my tabs are 380's i run them level with the bottom as often as i can. The boat had 3A's form the factory, and then was switched to 5's and boxes. Power is 598 tall decks, 14-71 blowers, tuned down a bit making 850hp with 3.8 psi of boost..

302Sport

i would go 18 X 29P or 30P 3 blades. Bigger diameter will help you still get on plane, and 3 blades carry the bow better. find a pair and try them, what do you have to lose???? dont try going to five blades then you really wont be able to get the nose up. mess with diameter and blades, pitch is only going to get your rpm's where you want them.

kvogt

I think you need more blades with 17.5 to 18 inch diameter.

302Sport

more blades is going to lift the stern, but ur the guy who should know cause your running way up top. did you have the same problem??????? i love surface drives by the way...

kvogt

My boat never porpoised, but it is very sensitive to props. I've never had a set of 4 blade cleavers that I was happy with (spend a fair amount of money with bblades trying to get them better). I had a set of Hoss 4 blade round ears that ran very well after bblades worked on them, but threw the blades off one of them. Now I have a set of 6 blade Herings with a high rake angle, these seem to run very well but I only have limited time on them before I tore the boat apart. Now I up-ed the power a little and lightened the boat?? We will see in the next month how it works. btw Since I switched to bblades for prop work I have been very happy with the results.

Try some different props even if the pitch isn't exactly right, you will get a feel how they carry the boat.

Kris Vogt

LongStoryShort

i apologize for bringing this topic up again, i see that it has been dead for several years...

I have a 94 TG with 780hp blower 540's and Teague platinum drives, with labbed props, i can get 82GPS on smooth water. i still have a porpus problem though, should i look into putting extention boxes on?

this boat is new to me, and im new to the "go fast" side of boating, so i apologize if i ask a dumb question.