GX390 not powerful enough for TW5050 (on paper)

Hi All,

I was about to purchase a TW5050 to go along with a GX390 as this seems to be a highly recommended budget setup. I spoke to my local supplier (BAR australia), they said I’d need a v-twin to power a tw5050 and directed me to their website for stats, and indeed it does appear to be too much for a GX390.


So why does it work for everybody on youtube? Are the stats extremely conservative? I’ve even seen a video of a guy running an 8gpm pump from a 390, he said it ran but was putting a lot of stress on the motor. Why wouldn’t I be able to run a tw5050 if he can do that?


It’s rated at 5gpm and 5000psi. The other guys can comment further, but typically you’ll see about 5gpm/2300psi out of a GX390. Unless you’re doing some sewer jetting you definitely don’t need 5000psi so that’s the wrong pump.

You can run an 8gpm pump but maybe see 1500psi if that.

Stop watching YouTube videos, they are very misleading. This is the site you want to get info from.


Now this is starting to make sense to me. Clearly I need to spend some more time here. Thank you.

1 Like

Just to add, you can run a pump rated for more psi than you need. It doesn’t necessarily make it the wrong pump so much as it will be a little bit more expensive. A beefier manifold on a pump is never a bad thing.

1 Like