- Location
- Charlotte NC
I would come down on your pop off some and go with a bigger needle and seat...
Reverse jetting- how does it work and what are advantages
- Thread starter krawler98
- Start date
I would come down on your pop off some and go with a bigger needle and seat...
Dual 46 Black jack
- Location
- Nor Cal
- Location
- Australia! North qld
That's going to be lean. Go 115 pilot 105 high, 2.3 n/s 80gr Spring. That's the advice I got for a similar engine and it worked well
- Location
- Nor Cal
Thank you rowsto. I'll probably try that first then. I've been buying a poop load of jets for this exact reason. Lol. I ordered new N/S yesterday and should get them by Tuesday. I'll let ya know how she does
Sent from my XT1254 using Tapatalk
- Location
- Nor Cal
Sent from my XT1254 using Tapatalk
tntsuperjet
Tntperformance-engineering.com
- Location
- Georgetown ca
Reverse jetting only works well if you have a boat that struggles to breath in the engine compartment.
If your have enough venting it won't run for crap or it will hurt the motor.
If your have enough venting it won't run for crap or it will hurt the motor.
Man, why ya got to tell me dat! haha
I WAS excited about putting mine in the water after finding out it was rich. Bubble busted!?
Why does Jetworks black jack carbs come reverse jetted? I dont want to start anything and I truly appreciate your opinion. I am just wanting it to be jetted correctly reverse or not! iwantagoodyearofjetskiing!
tntsuperjet
Tntperformance-engineering.com
- Location
- Georgetown ca
Well I can't speak for black jack carb.
But the only reason would be they have a strong vacuum signal on main jet circuit that causes a rich condition on top.
But I can say a Rockter hull, tiger craft, almost all the free ride boats with only engine venting coming through handle pole reverse jetting works pretty well.
Soon as you add hood vents it doesn't work it so well.
Small amount like say a
130 low 125 high can work good for free ride.
But stuff like 140 low with 110 high. Not so much
But the only reason would be they have a strong vacuum signal on main jet circuit that causes a rich condition on top.
But I can say a Rockter hull, tiger craft, almost all the free ride boats with only engine venting coming through handle pole reverse jetting works pretty well.
Soon as you add hood vents it doesn't work it so well.
Small amount like say a
130 low 125 high can work good for free ride.
But stuff like 140 low with 110 high. Not so much
Thanks for your input man! I am glad you post on other things in the forum, you have a lot of knowledge to share with people like me that want to get the most of their set ups.
tntsuperjet
Tntperformance-engineering.com
- Location
- Georgetown ca
No problem
- Location
- Nor Cal
I'm stock duel SBN44's with a 62t/61x 84mm flatwater port motor with lightened flywheel, B pipe, msd, high comp. What would you recommend? A guy that gave me my jet specs has almost the same setup as me and I've never rode a more responsive ski!
Sent from my XT1254 using Tapatalk
tntsuperjet
Tntperformance-engineering.com
- Location
- Georgetown ca
When you say soneone has same setup as you.
If you have same hull with same engine venting in the hull then you should be able to use same jetting he has. You say you like it why not try it
But without knowing your porting and prop specs.
Most people don't realize if you have even a slightly larger prop you need more jet
But I like to start with 120-125 lows and 135 high jets and run the motor with stock carbs and figure out where my my screws are and then fine tune the jetting from there.
I always want my low speed screws at 1 turn, because there really designed to control idle fuel.
So if you have to big of a low speed jet you end up with low speed screws to far closed and that greatly increases lean run away risks. If your low speed screws are less then 1 turn its not if. But when will you have a lean runaway.
High speed screws I like at 3/4 to 1 turn.
This way you have more controlled fuel in a jet and still just little fine tuning room with the screws
Once u get the high speed screws past 1-1/4 they have to much wiggle room and jetting is inconsistent
In a race boat I like my high speed screws 0-1/2 out. Has best fuel control and rider can't lean boat down to hurt it
. But room to Richen if you should get a cool day or water condition.
But on a refined tune free ride boat I want high speed at 1/2 turn. Good control and room to adjust. If I need more then 1/2 turn adjustment something is wrong with motor and needs attention
Keep in mind it takes time to get your jetting that fine tuned.
But anyone can do it if you spend the time bracketing.
Example.
125 low. 135 high.
5 seconds of idle stab throttle.
Gurgles then pulls clean. Tells me I'm not far off. If idles 5 seconds and gurgles never pulls clean. I know I'm outside tunable range with those jets.
If idle then bogs, Richen both low and high. Remember. Just because your boat not moving doesn't mean your only in low speed jetting, jetting is throttle dependent more so then boat speed or engine rpm.
Look at a engine lean runaway. It's turning 7,000 rpm plus with throttle closed. Pure low speed jetting problem.
So if I have a bad bog I will first listen to the sound of my idle. Am a little lazy feeling and yang yang sounding. Or is it little gu gu crackle sounding. If ts crackle and girgly idle I know I'm Ritch on bot and the lean big is from lean high speed circuit. So clean up idle with low speed screw and get strong idle. Now lean bog is really bad. Open high speed screw 2.5 turns out. How's the bog now.
Better but still big bog, I know I need to go up at least 5 Five being 125 to 130.
Now out the high speed screw back to one increase main jet back to same test.
Once I get that all sorted out now I do a roll on roll off on plane run.
If the boat sounds lean when your letting off slow your high speed jet to small. Go bigger again.
Now it won't pull clean right away.
Now address fuel delivery with needle and seat and pop off.
Hope that helps
If you have same hull with same engine venting in the hull then you should be able to use same jetting he has. You say you like it why not try it
But without knowing your porting and prop specs.
Most people don't realize if you have even a slightly larger prop you need more jet
But I like to start with 120-125 lows and 135 high jets and run the motor with stock carbs and figure out where my my screws are and then fine tune the jetting from there.
I always want my low speed screws at 1 turn, because there really designed to control idle fuel.
So if you have to big of a low speed jet you end up with low speed screws to far closed and that greatly increases lean run away risks. If your low speed screws are less then 1 turn its not if. But when will you have a lean runaway.
High speed screws I like at 3/4 to 1 turn.
This way you have more controlled fuel in a jet and still just little fine tuning room with the screws
Once u get the high speed screws past 1-1/4 they have to much wiggle room and jetting is inconsistent
In a race boat I like my high speed screws 0-1/2 out. Has best fuel control and rider can't lean boat down to hurt it
. But room to Richen if you should get a cool day or water condition. But on a refined tune free ride boat I want high speed at 1/2 turn. Good control and room to adjust. If I need more then 1/2 turn adjustment something is wrong with motor and needs attention
Keep in mind it takes time to get your jetting that fine tuned.
But anyone can do it if you spend the time bracketing.
Example.
125 low. 135 high.
5 seconds of idle stab throttle.
Gurgles then pulls clean. Tells me I'm not far off. If idles 5 seconds and gurgles never pulls clean. I know I'm outside tunable range with those jets.
If idle then bogs, Richen both low and high. Remember. Just because your boat not moving doesn't mean your only in low speed jetting, jetting is throttle dependent more so then boat speed or engine rpm.
Look at a engine lean runaway. It's turning 7,000 rpm plus with throttle closed. Pure low speed jetting problem.
So if I have a bad bog I will first listen to the sound of my idle. Am a little lazy feeling and yang yang sounding. Or is it little gu gu crackle sounding. If ts crackle and girgly idle I know I'm Ritch on bot and the lean big is from lean high speed circuit. So clean up idle with low speed screw and get strong idle. Now lean bog is really bad. Open high speed screw 2.5 turns out. How's the bog now.
Better but still big bog, I know I need to go up at least 5 Five being 125 to 130.
Now out the high speed screw back to one increase main jet back to same test.
Once I get that all sorted out now I do a roll on roll off on plane run.
If the boat sounds lean when your letting off slow your high speed jet to small. Go bigger again.
Now it won't pull clean right away.
Now address fuel delivery with needle and seat and pop off.
Hope that helps
tntsuperjet
Tntperformance-engineering.com
- Location
- Georgetown ca
When you say soneone has same setup as you.
If you have same hull with same engine venting in the hull then you should be able to use same jetting he has. You say you like it why not try it
But without knowing your porting and prop specs.
Most people don't realize if you have even a slightly larger prop you need more jet
But I like to start with 120-125 lows and 135 high jets and run the motor with stock carbs and figure out where my my screws are and then fine tune the jetting from there.
I always want my low speed screws at 1 turn, because there really designed to control idle fuel.
So if you have to big of a low speed jet you end up with low speed screws to far closed and that greatly increases lean run away risks. If your low speed screws are less then 1 turn its not if. But when will you have a lean runaway.
High speed screws I like at 3/4 to 1 turn.
This way you have more controlled fuel in a jet and still just little fine tuning room with the screws
Once u get the high speed screws past 1-1/4 they have to much wiggle room and jetting is inconsistent
In a race boat I like my high speed screws 0-1/2 out. Has best fuel control and rider can't lean boat down to hurt it. But room to Richen if you should get a cool day or water condition.
But on a refined tune free ride boat I want high speed at 1/2 turn. Good control and room to adjust. If I need more then 1/2 turn adjustment something is wrong with motor and needs attention
Keep in mind it takes time to get your jetting that fine tuned.
But anyone can do it if you spend the time bracketing.
Example.
125 low. 135 high.
5 seconds of idle stab throttle.
Gurgles then pulls clean. Tells me I'm not far off. If idles 5 seconds and gurgles never pulls clean. I know I'm outside tunable range with those jets.
If idle then bogs, Richen both low and high. Remember. Just because your boat not moving doesn't mean your only in low speed jetting, jetting is throttle dependent more so then boat speed or engine rpm.
Look at a engine lean runaway. It's turning 7,000 rpm plus with throttle closed. Pure low speed jetting problem.
So if I have a bad bog I will first listen to the sound of my idle. Am a little lazy feeling and yang yang sounding. Or is it little gu gu crackle sounding. If ts crackle and girgly idle I know I'm Ritch on bot and the lean big is from lean high speed circuit. So clean up idle with low speed screw and get strong idle. Now lean bog is really bad. Open high speed screw 2.5 turns out. How's the bog now.
Better but still big bog, I know I need to go up at least 5 Five being 125 to 130.
Now out the high speed screw back to one increase main jet back to same test.
Once I get that all sorted out now I do a roll on roll off on plane run.
If the boat sounds lean when your letting off slow your high speed jet to small. Go bigger again.
Now it won't pull clean right away.
Now address fuel delivery with needle and seat and pop off.
Hope that helps
If you have same hull with same engine venting in the hull then you should be able to use same jetting he has. You say you like it why not try it
But without knowing your porting and prop specs.
Most people don't realize if you have even a slightly larger prop you need more jet
But I like to start with 120-125 lows and 135 high jets and run the motor with stock carbs and figure out where my my screws are and then fine tune the jetting from there.
I always want my low speed screws at 1 turn, because there really designed to control idle fuel.
So if you have to big of a low speed jet you end up with low speed screws to far closed and that greatly increases lean run away risks. If your low speed screws are less then 1 turn its not if. But when will you have a lean runaway.
High speed screws I like at 3/4 to 1 turn.
This way you have more controlled fuel in a jet and still just little fine tuning room with the screws
Once u get the high speed screws past 1-1/4 they have to much wiggle room and jetting is inconsistent
In a race boat I like my high speed screws 0-1/2 out. Has best fuel control and rider can't lean boat down to hurt it
. But room to Richen if you should get a cool day or water condition. But on a refined tune free ride boat I want high speed at 1/2 turn. Good control and room to adjust. If I need more then 1/2 turn adjustment something is wrong with motor and needs attention
Keep in mind it takes time to get your jetting that fine tuned.
But anyone can do it if you spend the time bracketing.
Example.
125 low. 135 high.
5 seconds of idle stab throttle.
Gurgles then pulls clean. Tells me I'm not far off. If idles 5 seconds and gurgles never pulls clean. I know I'm outside tunable range with those jets.
If idle then bogs, Richen both low and high. Remember. Just because your boat not moving doesn't mean your only in low speed jetting, jetting is throttle dependent more so then boat speed or engine rpm.
Look at a engine lean runaway. It's turning 7,000 rpm plus with throttle closed. Pure low speed jetting problem.
So if I have a bad bog I will first listen to the sound of my idle. Am a little lazy feeling and yang yang sounding. Or is it little gu gu crackle sounding. If ts crackle and girgly idle I know I'm Ritch on bot and the lean big is from lean high speed circuit. So clean up idle with low speed screw and get strong idle. Now lean bog is really bad. Open high speed screw 2.5 turns out. How's the bog now.
Better but still big bog, I know I need to go up at least 5 Five being 125 to 130.
Now out the high speed screw back to one increase main jet back to same test.
Once I get that all sorted out now I do a roll on roll off on plane run.
If the boat sounds lean when your letting off slow your high speed jet to small. Go bigger again.
Now it won't pull clean right away.
Now address fuel delivery with needle and seat and pop off.
Hope that helps
Quinc
Buy a Superjet
- Location
- California
What does one turn on the adjustment screw equal to in jet size? Example would one turn out be the same as going up 1 jet size?
2HIGH4U
Princess POWER
- Location
- BrisbaneAUS
I really like reading your replies on this sort of stuff ,thanks for sharing your knowledge, I know many who appreciate your know how and experienceWhen you say soneone has same setup as you.
If you have same hull with same engine venting in the hull then you should be able to use same jetting he has. You say you like it why not try it
But without knowing your porting and prop specs.
Most people don't realize if you have even a slightly larger prop you need more jet
But I like to start with 120-125 lows and 135 high jets and run the motor with stock carbs and figure out where my my screws are and then fine tune the jetting from there.
I always want my low speed screws at 1 turn, because there really designed to control idle fuel.
So if you have to big of a low speed jet you end up with low speed screws to far closed and that greatly increases lean run away risks. If your low speed screws are less then 1 turn its not if. But when will you have a lean runaway.
High speed screws I like at 3/4 to 1 turn.
This way you have more controlled fuel in a jet and still just little fine tuning room with the screws
Once u get the high speed screws past 1-1/4 they have to much wiggle room and jetting is inconsistent
In a race boat I like my high speed screws 0-1/2 out. Has best fuel control and rider can't lean boat down to hurt it
But on a refined tune free ride boat I want high speed at 1/2 turn. Good control and room to adjust. If I need more then 1/2 turn adjustment something is wrong with motor and needs attention
Keep in mind it takes time to get your jetting that fine tuned.
But anyone can do it if you spend the time bracketing.
Example.
125 low. 135 high.
5 seconds of idle stab throttle.
Gurgles then pulls clean. Tells me I'm not far off. If idles 5 seconds and gurgles never pulls clean. I know I'm outside tunable range with those jets.
If idle then bogs, Richen both low and high. Remember. Just because your boat not moving doesn't mean your only in low speed jetting, jetting is throttle dependent more so then boat speed or engine rpm.
Look at a engine lean runaway. It's turning 7,000 rpm plus with throttle closed. Pure low speed jetting problem.
So if I have a bad bog I will first listen to the sound of my idle. Am a little lazy feeling and yang yang sounding. Or is it little gu gu crackle sounding. If ts crackle and girgly idle I know I'm Ritch on bot and the lean big is from lean high speed circuit. So clean up idle with low speed screw and get strong idle. Now lean bog is really bad. Open high speed screw 2.5 turns out. How's the bog now.
Better but still big bog, I know I need to go up at least 5 Five being 125 to 130.
Now out the high speed screw back to one increase main jet back to same test.
Once I get that all sorted out now I do a roll on roll off on plane run.
If the boat sounds lean when your letting off slow your high speed jet to small. Go bigger again.
Now it won't pull clean right away.
Now address fuel delivery with needle and seat and pop off.
Hope that helps
- Location
- Nor Cal
Alrighty boys!!!! So I did what I said and reverse jetting my poop and no joke, gave me the extra bottom end hit to be able to flatwater flip my glass 61x Phantom! I can't believe the difference it truly made. Runs amazing and plugs are perfect chocolate brown. If anyone else is thinking about doing this for the extra bottom there looking for I would do it!
Sent from my XT1254 using Tapatalk
Sent from my XT1254 using Tapatalk