Need setup help!!

[tdc53190]

Hi guy's I have a 90 hydrostream hst with a 92 260 with cle and having some trouble with the setup. It currently has 18.5 in of set back with hydraulic jack plate and a 20in mid can only get 84 mph out of it and that was with a 28 chopper and only could turn it 6100. I turn a 26 chopper 7600 and ran 80. Do I have to much set back and it porpoises around 80 any help would be appreciated thanks Troy

[bigbluechevy454]

Good way to tell if u have to much set back is If you have to use negative trim to hold the bow down. Prop style will have a affect on that also. Im not a hst owner but thats a general rule ive found to be true . Messing around with boats i have just because your buddy has the same boat may not mean u should use same jackplate because boats maybe rigged differently and center of gravity will change. Having said all that a think a sport cleaver or et cut prop will likely run better on your boat

[tdc53190]

Thanks for the info I don't have to use negative trim to keep the bow down so I guess I'm good on that. I'm trying to get my buddy's 28 cleaver and try that to see what happens.

[bigbluechevy454]

Ive found big choppers hard to turn There ment for heavy hulls that need lots of bow lift. That cleavor is complete opposite or the chopper. Lots of stern lift. A yamaha drag or et cut is in the middle. Et having maybe a bit more bow lift. Hope this helps

[GETBOATS]

are you sure of your rpm numbers? only 2 inches of pitch change won't net a 1500 rpm change unless there is something else going on. just a thought..gb

[bigbluechevy454]

Would if one chopper is small ear and one is big ear. I didnt even catch that earlier

[wetsidedown]

27in. set back with drive shaft at right angle to the centre pad and the top of prop shaft even with bottom of centre pad.
My HST(90) was a heavy 900lb. stripped. Ran 105 with 28ET, both with 260 & 280 blocks, 8200 rpm.