What is the purpose of moving the intake/pump? Ive been reading about people setting their pumps back...does anyone move them forward?

Sent from my SCH-I535 using SoCal Jet Boats mobile app

What is the purpose of moving the intake/pump? Ive been reading about people setting their pumps back...does anyone move them forward?

Sent from my SCH-I535 using SoCal Jet Boats mobile app

Most people set back there pumps for a performance gain, by moving the pump back you are moving the thrust line of the pump back creating more lift. You'll see a lot of race boats and some hotrod river boats with setbacks. Also moving the intake back allows the hand hole to be outside the boat (being able to put a pop off valve on) and makes more room in the drive line to be able to add a jet-a-way.

I'm a new guy around so this may be an "obvious" thing, but I don't know the answer. When you guys are talking about --set back-- are you referring to moving the whole jet and housing to the outside of the transom of the boat?? I do a lot of picture looking, (because there aren't a whole lot of drag/jet boats in my area to look at) and I notice some jets have the hand hole/clean out on the outside and some have it on the inside of the boat. Is this what you guys are talking about, or  is there another reason for that clean out placement???
Thanks, Ken

I'm a new guy around so this may be an "obvious" thing, but I don't know the answer. When you guys are talking about --set back-- are you referring to moving the whole jet and housing to the outside of the transom of the boat?? I do a lot of picture looking, (because there aren't a whole lot of drag/jet boats in my area to look at) and I notice some jets have the hand hole/clean out on the outside and some have it on the inside of the boat. Is this what you guys are talking about, or  is there another reason for that clean out placement???
Thanks, Ken

Most people set back there pumps for a performance gain, by moving the pump back you are moving the thrust line of the pump back creating more lift. You'll see a lot of race boats and some hotrod river boats with setbacks. Also moving the intake back allows the hand hole to be outside the boat (being able to put a pop off valve on) and makes more room in the drive line to be able to add a jet-a-way.


Hey ken, in short, yes, when you see the handhole either halfway out or all the way out of the transom, it is setback...

sent from my smarter than me phone

Most people set back there pumps for a performance gain, by moving the pump back you are moving the thrust line of the pump back creating more lift. You'll see a lot of race boats and some hotrod river boats with setbacks. Also moving the intake back allows the hand hole to be outside the boat (being able to put a pop off valve on) and makes more room in the drive line to be able to add a jet-a-way.


Hey ken, in short, yes, when you see the handhole either halfway out or all the way out of the transom, it is setback...

sent from my smarter than me phone

Good to know, so with the setback, are people removing their pump set up, 'glassing in the old pick up hole, and making a new hole in the rear of the boat, after remounting everything rearward?
 
Which brings up another question, a pop off valve.... Like a pop off on a blower set up? Why would you need one on a jet? Racing only, average boat, safety reason?? Never seen one until I came onto this site.

BTW, I sure didn't mean to "hi-jack" this thread with my questions, so I'll move them if wanted.
Thanks, Ken

Im actually setting the pump back in my family boat right now. I need more interior space. I also hope to get the boat to free up a little as well. Its a 21' open bow and shes a PIG....