FX-1 Jetting for SJ pump suggestions

swapmeet

swapmeet

Brotastic
Location
Arlington TX
Alright, I have a ported 701 with FX1 B-pipe. About to add a Protec head that should yeild 175-180psi. It has a single SBN44 carb on it.

When I last ran the motor it was running on the stock FX1 pump (~120mm) with what I believe is a stock prop. It ran great and other than having way too much top end on the prop.

I have no idea what jets/ spring or needle & seat is in the carb currently.

I'm about to put this engine up against a 144mm SJ pump with a Scat 12/17 prop in my new FC hull.

Since there are so many people with FX1's with big pumps, I figure ya'll can get me close. I just ordered a bunch of jets, but i'm not sure I ordered big enough jets. The biggest one I ordered was a 147.5.

Unless ya'll suggest it, I don't plan on go tearing into my well tuned carb until I know it needs to be changed. But its nice being able to tap into the wisdom of other members of the board.
 
motoman96

motoman96

Banned
Location
Lodi Cali
I don't remember what I was running with my setup similiar to yours, but it was a powerbomb 48 carb an it ripped. It's probably gonna be for sale soon too. Should know by the end of the week.
 
DirtyJ

DirtyJ

Freedom aint free no more
Location
Alliston, Ontario, Canada
swapmeet said:
Alright, I have a ported 701 with FX1 B-pipe. About to add a Protec head that should yeild 175-180psi. It has a single SBN44 carb on it.

When I last ran the motor it was running on the stock FX1 pump (~120mm) with what I believe is a stock prop. It ran great and other than having way too much top end on the prop.

I have no idea what jets/ spring or needle & seat is in the carb currently.

I'm about to put this engine up against a 144mm SJ pump with a Scat 12/17 prop in my new FC hull.

Since there are so many people with FX1's with big pumps, I figure ya'll can get me close. I just ordered a bunch of jets, but i'm not sure I ordered big enough jets. The biggest one I ordered was a 147.5.

Unless ya'll suggest it, I don't plan on go tearing into my well tuned carb until I know it needs to be changed. But its nice being able to tap into the wisdom of other members of the board.
Click to expand...

Pretty sure you gonna need bigger jets then that Bro.

I had a very similar setup and the main was 165 I believe the pilot was around 130? The n&s was 2.3 and I totally forget what the pop-off was. Is you motor ported? Thats another thing to factor in.

I hope this help you get a bit closer to where you want to be.
 
swapmeet

swapmeet

Brotastic
Location
Arlington TX
DirtyJ said:
Pretty sure you gonna need bigger jets then that Bro.

I had a very similar setup and the main was 165 I believe the pilot was around 130? The n&s was 2.3 and I totally forget what the pop-off was. Is you motor ported? Thats another thing to factor in.

I hope this help you get a bit closer to where you want to be.
Click to expand...

Ok, thanks that helps. The engine has been ported by GroupK (Hammer Porting). I guess I need to order more jets.
 
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