Has anyone installed a gx390 carb onto a 6.5hp clone or predator motor? What were your engine builds and general rpm ranges? I have a mild built clone I'm thinking about putting a gx390 carb onto and was curious to see what others have noticed. My build will generally be in the 5000-7500 rpm range. Also did you guys leave the gx390 carb with stock jets or did you rejet the carb and to what size main/idle jets? I want to install this without a fuel pump and also was wondering if you need to get an adapter to fit the gx390 carb onto 6.5hp clones? Would the black insulator for the carb fit onto the 6.5hp clone as an adapter or would I need to purchase an after market adapter? Thank you.
You most definitely need an intake manifold to put a 390 on a small block head ..and it is kind of overkill for a mild build . the throttle hook up is a little tricky . Barry young and a couple other people make huge HP with the 390 carbs dover has the manifold I believe me might have one too . unless you are running like a 28.5/25 set up though it's too much carb
This works pretty good too you know and you get some screws to adjust.
https://www.youtube.com/watch?v=PQ9U7flWop0
But my carbs are the ugly step sisters of the minibike world lol....
( that's a carb off a 10 hp Tecumseh snowblower with a tillotson intake and air filter kit. Hard to get simpler )
https://www.youtube.com/watch?v=PQ9U7flWop0
But my carbs are the ugly step sisters of the minibike world lol....
( that's a carb off a 10 hp Tecumseh snowblower with a tillotson intake and air filter kit. Hard to get simpler )
The 390 carb works well with 27/25 valve head also... Works well also with 260 duration cams... Works well with stock bore and stroke engine, works well with a bored and stroked engine...
I have never run a 390 on gas so I can't answer that but on alky they are easy to tune...
If it is a genuine Gx390 carb. Leave the Etube stock, move the oring on the low jet above the centre hole, and start with a jetting of .036 low jet and a .067 high jet...
And hang on...
I have never run a 390 on gas so I can't answer that but on alky they are easy to tune...
If it is a genuine Gx390 carb. Leave the Etube stock, move the oring on the low jet above the centre hole, and start with a jetting of .036 low jet and a .067 high jet...
And hang on...
the 390 carb works GREAT.
currently on stock cam and ports it will work!
works on the pump gas too.
i tried mine out yesterday so i know for a fact it works. Either way you should probably get a fuel pump. Unless you don't care about having to pressurize the tank with your mouth every so often so fuel will go into the carb bowl like i need to do IT ISNT FUN!
currently on stock cam and ports it will work!
works on the pump gas too.
i tried mine out yesterday so i know for a fact it works. Either way you should probably get a fuel pump. Unless you don't care about having to pressurize the tank with your mouth every so often so fuel will go into the carb bowl like i need to do IT ISNT FUN!
dangerous to add pressure to a tank in place of a fuel pump.
5.5 HP Evinrude Johnson Pressurized Fuel Tanks
5.5 HP Evinrude Johnson Pressurized Fuel Tanks