jet setback

[TBONE1904]

I have owned by jet boat for 6 months and finally reliazed I have my pump setback. My question is why do it, and what performance gains are there. Does this mean i defiantly need to put my nitrous kit on?!!!! Any help is appreciated

[victorfb]

you may infact have a differant pump itself. some pumps were designed to be set back more. i believe the berk JE or JF was set back with the hand hole on the outside of the transum. this may be what you are seeing. you will need to look at the tag ontp the bearing housing on the pump and tell us what pump you have. then all the other details such as hull, engine, HP, ect. and of course what you plan to use the boat for. recreation, speed runs, ect.

[TBONE1904]

its a Berekley 12jg. if the hand hole is inside the transom and it has that square fiberglass enclsure around the jet that allows it to be "setback" passed the transom, that means its setback..right?

[TBONE1904]

its a 19' Bahner. right now it has a 454 chevy and i plan to have fun with it at the river. I am a gearhead so i wouldnt mind messin with different engine combos, as i do have a 1000 HP super gas motor, for the nova, about 85% complete.

[clownpuncher]

Here's a pic of my 12jg setback.
http://www.***boat.com/image_center/...RM0001-med.JPG

[TBONE1904]

Here are some pics of mine. Its a 12JG Berkley pump. I just bought a place divertor but it isnt installed yet. Is my pump indeed "setback"?
http://www.***boat.com/image_center/..._00059-med.JPG
http://www.***boat.com/image_center/..._00060-med.JPG

[flat broke]

Yes, your pump is set back. The next investment I would make would be to get a different transom adapter made. One of the biggest safety benefits of that much set back is that the hand hole cover is on the outside of the transom. Should the cover break (and it can happen to anything from a boat with a warm 460 to a 800hp bbc), your current transom adapter would keep that water inside the boat and sink it in a heartbeat. With the hand hole cover outside the boat, you elimiate that risk for a potential entry point for water. The other obvious benefit would be better access to the hand hole cover, and the ability to clean it out with the boat in the water.
Chris

[TBONE1904]

thanks for the headsup. what are the performance benifits of the setback?

[flat broke]

By moving the pump further back, you give it more leverage against the weight of the hull when trying to create lift. In theory the further the thrust line is from the boat, the more leverage it would have when making trim changes etc. That and in your boat, it allowed them to give you more interior space because as the pump moved back, so did the motor.
Chris