How hard was this to build?
It’s not hard at all to do it the way he did it… it doesn’t look like he has a gearbox on them, they look like straight up direct drive, so you just bolt it right to the machine, install and set an unloader and think of a crafty way to mount it. Voila !
Build your own machine. DO you have a harbor freight nearby?
I run 4 gpm with an 8 hp predator engine. It has made me over 10k so far. Haven’t had any problems.
Yes i already looked it up they have one in stock for $310. I just worry that pump he has on his is to strong for the motor. Should i go with a 5pm x 2800psi pump? Or 4k x4gpm
I would go with a 4gpm pump honestly. The thing is, if the pump is too strong, the psi will drop. You will still get high gpm. A 4 gpm machine will run comfortably off of a home-owner water supply. Any higher and some jobs will require you to transport your own water.
The 301 cc harbor freight engine can be had for $220. A 4 gpm AR pump will cost you $230 from WaterCannon.com. I built a simple wooden mount for mine, but if you want you could buy a metal one. After that I bought 200’ of simpson hose from amazon. You can buy it in 1 200’ length for $150, or 2 100’ lengths for $90 each, which is what I did. Now your unit can sit in the truck while you take the hose around the house. Much easier. I would also recommend an xjet. All of this can be had for less than $1k.
I started out in much the same scenario you’re in. If you need any help being frugal, let me know.
Not hard to build just slide them together then 4 bolts, but i built my own motor mount and used chevy sway bar bushings for dampeners. 4gpm is definitely cheaper you don’t have to use a tank, bought my tank off of facebook marketplace.Piping and all the other junk that comes with bigger machines. A 13hp predator is plenty strong enough for a 5.5gpm pump doesnt bog at all when running. A 4gpm rig would be able to fit in the back of your truck save from buying trailer.
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4000?
13hp enough to get 4k? I thought it required more.
Actually scratch the first answer its 3600 then when i let off its 4000
You don’t need 4k PSI.
Yep. I don’t think anyone was looking for 4k. I have a similar engine and will be replacing the pump within a year. Just curious what he was getting pressure wise. I want to make sure I am getting enough to do conrete right.
Ya im seriously considering this i just found a good honda gx390 motor for $250 im going to look at it friday. Never tought id come to this in 2 days haha.
Returned a 3200psi 3.3gpm
To looking for a $1300 rig
To trying to build my own.
Lots of info from all the veterans on here
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This site is amazing,.
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What is a gx360 lol never seen one before. Im by far no veteran lol still a newbie, just do alot of reading, just read alot watch alot this forum does wonders. Heres a formula to help match engine to get a reccomend horsepower gpm x psi x .0007 mine said 15hp when i did so i guess theres a little wiggle room i got a 13hp so. @fredled i was trying to get the most out of my pump im never going to need 4000 but I’m getting the most out of the pumps.
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Gx360 is a 13hp honda engine
Fixed that for you ^^
Re-edited. I goofed. Had never heard of the 360 motor, and assumed it was a typo. My bad.
After some searching a gx360 is a liquid cooled 13hp motor never seen one before must be discontinued looks expensive maybe good for heavy use since liquid cooled.Thanks @florida_condo_cleani
That is fascinating. I’d never seen such a small motor that was liquid cooled. I wonder if any manufacturers still make something similar 
Anyone considering building a unit needs to follow the simple math to determine horsepower requirements.
Gallons per minute x (times) psi
=y
Take y and divide by 1,100
4x3500=14,000
14,000/1,100=12.72 horsepower
I swear I have posted this formula 10 times this season lol
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