What up everyone! I’ve got a 701 bored and ported to about a 731 with a hot rod crank. Also have a ported b-pipe. I need help tuning my dual 44s. What does everyone recommend for jetting specs? I’m riding at around 1,500ft. I’ve flipped around jets and still can’t seem to find a happy spot. It would be for flat water freestyle riding. Any help is greatly appreciate!!
701 dual sbn 44 jetting
- Thread starter Patty14
- Start date
Quinc
Buy a Superjet
- Location
- California
Carburetor (specs) Database: SuperJet and Blaster 1
The SuperJet and B1 Carburetor Database I'm in the process of putting a pair of 46mm Mikuni's on my SJ to see if I like them and have been thinking of how I plan to jet them. I then though how helpful it would be if we all had a large database list of what others run with their given setup...
www.x-h2o.com
waxhead
wannabe backflipper
- Location
- gold coast
re they oem 44 760 carbs
Yes
- Location
- Charlotte, NC
Try 117.5-125 pilot, 130-135 main 2.0 n/s 95g spring, 25psi popoff 1 turn out on both screws with oem flame arrestors 1 screen. That should get you close enough to fine tune.
Also the hull you're running your engine in will affect jetting as well. I had 125 pilots 135 mains 25psi popoff in my superjet with similar setup as yours.
Also the hull you're running your engine in will affect jetting as well. I had 125 pilots 135 mains 25psi popoff in my superjet with similar setup as yours.
waxhead
wannabe backflipper
- Location
- gold coast
130 low
110 high
2.3 n/s
95 gram springs
this will have you close. make sure your pipe is set up correctly
110 high
2.3 n/s
95 gram springs
this will have you close. make sure your pipe is set up correctly
- Location
- Charlotte, NC
When I tried reverse jetting in my superjet, it ran like crap, loaded up, burned lots of fuel as well. Reverse jetting seems to work better on skis with no hood breathers, only pole breathers. When I went back to jetting like I listed, my throttle response came back. This was in my superjet with a rrp dual breather pole and stock hood.
waxhead
wannabe backflipper
- Location
- gold coast
Ok fair enough.
waxhead
wannabe backflipper
- Location
- gold coast
If you were loading up with poor throttle response on the setting I gave you. You have another issue.
- Location
- Illinois
Sounds like you need to reconfigure your pole breathers, and/or add a vent in the hood. That alone should not effect your jetting that drastically.
I'm currently reverse jetted in my '10 sj, stock hood breathers,130p 125 m, 50psi pop off, 2 1/4 turns out on lows (fine thread screws) don't recall high screws exact but think I'm like 1/2 turn out. Oem FA. Stock 760 64x cylinder.
Approx 400 elevation. Very snappy and starts easy (hence why I like to use a lot of the low speed screw, and counter it with high pop off). Running b pipe wet and cool. It's not "perfect" but runs pretty well.
- Location
- Charlotte, NC
No, it was the carb settings. Reverse jetting and low popoff dont always work in every combination. At least in mine it didnt. Now, that engine is going into a new hull so maybe reverse jetting will work. It could have to do with my riding style too, I'm not an idle blipper haha.
- Location
- Charlotte, NC
Yeah I wasnt running anywhere near 50psi popoff. That is stock popoff territory. Most reverse jetting tunes I've seen run half that popoff psi. The popoff recommendation wax gave was a 2.3 n/s with a 95g spring=20psi. to have 50psi popoff you have to be running a 1.5 n/s with a 115g spring which is stock.
waxhead
wannabe backflipper
- Location
- gold coast
How is your pipe setup. What’s the rest of the spec of your engine
- Location
- Charlotte, NC
Lpw 62t "freeride" ported 735. Tnt ss chamber, 49mm headpipe, dedicated line to headpipe from the pump, 1/2 turn on top screw 1/4 turn on middle. .25 restrictor in bypass from flow control valve. Jetting specs from paul were not reverse jetted. We talked several times about reverse jetting and decided to try it. Tried several different specs including one very Similar to yours. He gave me some reverse specs to try as well. Just didnt like it. It was a little mushy on the bottom, would run great once all the excess fuel burned off from holding it open, then once back in the low circuit it would load up again. I think it was from the low popoff from the large seat leaking fuel causing the engine to load up in the popoff circuit. Also known as the fuel dribble. And going to a smaller low jet with higher popoff solved the issue. This engine seemed to like the popoff at least 25psi. At 18-20psi it would dribble. I'm running dual 61x flame arrestors with 1 screen. They were trimmed a little to clear the head.
I have no doubt I'll have to retune the engine when I get my next hull finished as it is a solid 25-30 lbs lighter and maybe reverse jetting will work. But in my heavy superjet, I did not like it.
I have no doubt I'll have to retune the engine when I get my next hull finished as it is a solid 25-30 lbs lighter and maybe reverse jetting will work. But in my heavy superjet, I did not like it.
Last edited:
waxhead
wannabe backflipper
- Location
- gold coast
your pipe is very wet./cold
With reverse jetting you do not want to run your pipe like you are, I would close the top the and the middle screws. Open the bottom 3/4
I don't run flow control valves but eave it in there. The bypass ?? are you restricting the water going over board some more ?? Put the restrictor on to the stinger side and use a 3-4mm restrictor in there, The majority of the water flow should be over board,
The ski came right after holding it on because the pipe finialy could get up to temp and make power.
With reverse jetting you do not want to run your pipe like you are, I would close the top the and the middle screws. Open the bottom 3/4
I don't run flow control valves but eave it in there. The bypass ?? are you restricting the water going over board some more ?? Put the restrictor on to the stinger side and use a 3-4mm restrictor in there, The majority of the water flow should be over board,
The ski came right after holding it on because the pipe finialy could get up to temp and make power.
- Location
- Charlotte, NC
My chamber is pretty warm to the touch after a good ride. The water temps I ride in most of the time are in the 80s-90s in the south. Getting the pipe too hot I've found can make it mushy on the bottom and lose some throttle response.
- Location
- Illinois
Early on after this setup was together I was in the low 20's of pop off (can't remember exact pressure, tried so many variables in short time), with am FA's, it ran well down low to mid, but I couldn't use enough low speed screw to make this damn thing cold start the way I like (I refuse to have to prime/choke a ski with a simple motor setup). Lots of jetting later, ended up back at a high pop off and feels exactly the same but would cold start consistently well.
You ain't wrong about the heavy hull part, it's a pig and on top of that, I probably weight almost as much as the ski lol.
waxhead
wannabe backflipper
- Location
- gold coast
if your pipe is not hot enough you will find that you end up with a mushy power band, You have to bring the pipe up to temp every time you want the power. This is the very same reason people all threw their water injection in the bin. It just means the pipe temp changes to much and it brings variation to the tuning required for the pipe.
How ever there is a 1000 different way to skin a cat and if its working for you then all good
waxhead
wannabe backflipper
- Location
- gold coast
yes you will get more hit in the low end and some more mid