RN superjet hesitation/fuel problem

[brando]

08 superjet twin carb 38mm
I’ve been having issues with a low end bog hesitation since I bought it, I recently went through the carbs and cleaned everything out and put back together. I took it out today with a full tank and it was running good but when I would turn right it would always shut off. Guessing an electrical issue.

By the end of the session it started bogging at high speeds and low speeds even more then it died and I couldn’t get it to start back up. Spark plugs are fine and when I took it home if I spray fuel mixture in the butterflies it will start and shut off. Any help on figuring out why it’s not getting fuel all the sudden? I double checked all the fuel lines everything is in correct place

 

[Big Kahuna]

You need to rebuild the carbs with oem rebuild kits first. Also replace the needle and seats and pop off spring.

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[brando]

You need to rebuild the carbs with oem rebuild kits first. Also replace the needle and seats and pop off spring.

Sent from my SAMSUNG-SM-G930A using Tapatalk

Ordered oem rebuild kit with new needle seats,springs,fuel lines,fuel filter and pulled the tank to clean out, let you know if I still have problem after replacing all that, thanks!

 

[Vumad]

Ordered oem rebuild kit with new needle seats,springs,fuel lines,fuel filter and pulled the tank to clean out, let you know if I still have problem after replacing all that, thanks!

You should be using a popoff gauge to make sure everything is correct. Needles and spring can sometimes be out of spec even new, and the popoff gauge is the easiest way to leak test the fuel pump. Sucks to think yourebuilt a carb and its not the issue only to find out the fuel pump was leaking. Also pleased with the JM allen head bolt kit, but not necessary. Just sometjing to consider ifalready paying shipping on a gauge.

Not sure if the 08 is capped the same as the 04 but removing the screw plugs and putting in longer adjustment screws as well as adding primer are considerations while working on the carbs. Not necessary but ifyou have extra time and money its a good investment into future tuning.

 

[brando]

You should be using a popoff gauge to make sure everything is correct. Needles and spring can sometimes be out of spec even new, and the popoff gauge is the easiest way to leak test the fuel pump. Sucks to think yourebuilt a carb and its not the issue only to find out the fuel pump was leaking. Also pleased with the JM allen head bolt kit, but not necessary. Just sometjing to consider ifalready paying shipping on a gauge.

Not sure if the 08 is capped the same as the 04 but removing the screw plugs and putting in longer adjustment screws as well as adding primer are considerations while working on the carbs. Not necessary but ifyou have extra time and money its a good investment into future tuning.

Yeah after reading this I got in touch with jetmanic and ordered the pop off tester, 4 long T handle adjusters and the primer kit. Didn’t really want to spend that much or put a primer kit but it’s all good. I’d rather spend the money now and get it all right so I can just ride and not have to keep pulling this thing apart.

Ya the 04-17 are capped the same, I just screwed through them and wedged out the brass case. Between the rebuild kit, filters, lines, tester, etc I’m at 300$ just to get these carbs right so hoping It runs perfect after. I’m new to stand ups and I’m realizing how expensive it is for everything. Super fun though that’s for sure.

 

[Vumad]

Yeah after reading this I got in touch with jetmanic and ordered the pop off tester, 4 long T handle adjusters and the primer kit. Didn’t really want to spend that much or put a primer kit but it’s all good. I’d rather spend the money now and get it all right so I can just ride and not have to keep pulling this thing apart.

Ya the 04-17 are capped the same, I just screwed through them and wedged out the brass case. Between the rebuild kit, filters, lines, tester, etc I’m at 300$ just to get these carbs right so hoping It runs perfect after. I’m new to stand ups and I’m realizing how expensive it is for everything. Super fun though that’s for sure.

Too bad i dont get a comission!

 

[brando]

Too bad i dont get a comission!

You should get a commission from Jetmanic for the plug lol thanks for the advice! I was actually racking my brain to why my carb didn’t have adjusters like the Mikuni website said I should have

 

[brando]

I replaced the the stock adjusters with T handles today and on one of the carbs the low side adjuster was competely screwed down. Weird cause I drilled the brass caps myself so I know no one has ever messed with them. Maybe that was my problem

 

[Big Kahuna]

I replaced the the stock adjusters with T handles today and on one of the carbs the low side adjuster was competely screwed down. Weird cause I drilled the brass caps myself so I know no one has ever messed with them. Maybe that was my problem

Jetting can be so precise that you can ket to where the screws are closed. From this point you can only add fuel but you cannot tune into a lean condition. Some SeaDoo' s use to come like this.

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[brando]

Need help guys, everything is back together. Full carb rebuild kit, needles,seats,springs, all oem mikuni. New fuel lines. Cleaned gas tank. New T handle adjuster screws, new spark plugs.

Went to start it up an hour ago and it only runs if im on the gas, it will completely die right away if i get off it. I started the aduster screws at Low 1 turn out, High 1.5 turns out. Messed with the adjusters in small increments for 45min before giving up cause its not changing much. What next?

 

[brando]

Pop off was 53-55, 115g springs, jets are oem 70 and 130

 

[Big Kahuna]

did you set your idle? sounds to simple, but have seen it before. Or you have clogs in both of your low speed circuits

 

[brando]

I haven’t messed with idle screw at all, same as it was before. I️ thought about turning it up but I shouldn’t have to cause it was perfect before. I don’t see how i could have any clogs I just went through everything maticulesly.

Does it make a difference if the air box is off? I had it off because to start it at first with dry lines I was putting gas mix straight down the carbs

 

[Vumad]

I haven’t messed with idle screw at all, same as it was before. I️ thought about turning it up but I shouldn’t have to cause it was perfect before. I don’t see how i could have any clogs I just went through everything maticulesly.

Does it make a difference if the air box is off? I had it off because to start it at first with dry lines I was putting gas mix straight down the carbs

You can hand choke the carbs with a stock airbox by putting your hand over the bell.

It's best to tune with a tach. I use a hardline tach because it's cheap and work well. My superjet likes to idle around 1200 but I like the idle at 1400. Any less than 1200 and it will stall. My X2 will purr at 800 rpm idle.

Start by turning your idle screw in half a turn. Just remember how many turns you move it and you can always put it back where it was.

When you took out your adjustment screws, did you turn them in all the way first counting before you took them out? Or did you just take them out without counting. If it's stock you should be able to get the specs for the factory screw settings. If you have a pipe then you may have to do a little tuning.

You started this because your low end wasn't running well. You may need to make a few adjustments to get everything just the way you like it and maybe something other than your carbs needs a little love. Don't be afraid to ask another local rider to meet up with you to help you figure it out.

I bet if you went to the sebastian freeride this weekend that someone there would be willing to give you some advice. Theres a ramp inside the camp ground where you can tinker with it before putting it in the surf. The ramp is only 2-3 minute drive from where they ride so I'm sure finding someone to help wont be an issue. I'm not going to make it this year but the people at the events are always looking out for each other.

@JetManiac

 

[Big Kahuna]

I haven’t messed with idle screw at all, same as it was before. I️ thought about turning it up but I shouldn’t have to cause it was perfect before. I don’t see how i could have any clogs I just went through everything meticulously.

Does it make a difference if the air box is off? I had it off because to start it at first with dry lines I was putting gas mix straight down the carbs

if your idle is down to much and you let off the gas the motor will die. If your flame arrestor is removed, your pop-off can be effected as well as your adjustments. You have made the air flow more efficient which can effect the way the ski runs. Always tune a ski setup exactly how you plan to ride it. Otherwise, when you put the FA back on, your tuning will be slightly off.

 

[brando]

You can hand choke the carbs with a stock airbox by putting your hand over the bell.

It's best to tune with a tach. I use a hardline tach because it's cheap and work well. My superjet likes to idle around 1200 but I like the idle at 1400. Any less than 1200 and it will stall. My X2 will purr at 800 rpm idle.

Start by turning your idle screw in half a turn. Just remember how many turns you move it and you can always put it back where it was.

When you took out your adjustment screws, did you turn them in all the way first counting before you took them out? Or did you just take them out without counting. If it's stock you should be able to get the specs for the factory screw settings. If you have a pipe then you may have to do a little tuning.

You started this because your low end wasn't running well. You may need to make a few adjustments to get everything just the way you like it and maybe something other than your carbs needs a little love. Don't be afraid to ask another local rider to meet up with you to help you figure it out.

I bet if you went to the sebastian freeride this weekend that someone there would be willing to give you some advice. Theres a ramp inside the camp ground where you can tinker with it before putting it in the surf. The ramp is only 2-3 minute drive from where they ride so I'm sure finding someone to help wont be an issue. I'm not going to make it this year but the people at the events are always looking out for each other.

@JetManiac

Yeah i got it to run and stay idle without shutting off but its idling at like 1200-1300 which i thought was kind of high. What do you guys usually run them? just depends on ski? I'm going tomorrow to put in the water and tune it while its under load. When i took out the original adjustment screws i did turn them in first and wrote down all the numbers, before messing with the idle screw i actually set them back to exactly what i was before and did very little. Yeah JetManiac told me about the sebastian ride but i wont be able to make it up this weekend, forecasting solid surf so should be fun for the guys going. Im hoping to get this thing dialed tomorrow

 

[brando]

if your idle is down to much and you let off the gas the motor will die. If your flame arrestor is removed, your pop-off can be effected as well as your adjustments. You have made the air flow more efficient which can effect the way the ski runs. Always tune a ski setup exactly how you plan to ride it. Otherwise, when you put the FA back on, your tuning will be slightly off.

Ya all that makes sense I never messed with idle adjustment but i guess all the seats,needles,springs and gaskets is enough to through the idle off. I hooked back up the FA and put like 3 full turns on the idle screw and it seems to be running ok, im sure ill probly have to turn up a little more once its under load but we'll see tomorrow

 

[Vumad]

Yeah i got it to run and stay idle without shutting off but its idling at like 1200-1300 which i thought was kind of high. What do you guys usually run them? just depends on ski? I'm going tomorrow to put in the water and tune it while its under load. When i took out the original adjustment screws i did turn them in first and wrote down all the numbers, before messing with the idle screw i actually set them back to exactly what i was before and did very little. Yeah JetManiac told me about the sebastian ride but i wont be able to make it up this weekend, forecasting solid surf so should be fun for the guys going. Im hoping to get this thing dialed tomorrow

In what you quoted. My superjet likes to idle at 1200 and i like it to idle around 1400. My x2 purrs at 800 but i set it higher. My yamahas wont run that slow.

 

[brando]

I just got back from ramp, when I first put it in it started right up but was smoking a lot so def running rich. I jumped on and took it around a little bit and was running ok but definitely not enough power pretty sluggish. Made a right turn and it shut off. So still having that problem which sounds electrical but i made sure nothing was pinching from the pole to the prop when turning right and the start/kill switch is like new so not sure why it’s doing that.. it wouldn’t start back up unless i turned the pole all the way to the left

Put it back on the trailer and started adjusting the lows and highs and idle and was messing around for about an hour and couldn’t get it right. Ran good sitting on the trailer in the water but once i jumped on and got it under load it was just bog and didn’t even want to start most of the time so I’d have to paddle it back to the trailer. Only twice i got t up on plane and the power was really sluggish

Would turning the adjusters in lean it out or make it richer? Also I’ve read threads on guys have the front low at say 1 turn out and the back low at 3/4 turn out, any tips on how to adjust properly cause i though you were suppose to tune hem in sync with each other

For a stock ski just I be running the Br7h? I’m running the br8hs now but I read he br7h is a hotter plug so maybe that will help? It also has the br7h stock for recommended spark plug on my exhaust

 

[Vumad]

I just got back from ramp, when I first put it in it started right up but was smoking a lot so def running rich. I jumped on and took it around a little bit and was running ok but definitely not enough power pretty sluggish. Made a right turn and it shut off. So still having that problem which sounds electrical but i made sure nothing was pinching from the pole to the prop when turning right and the start/kill switch is like new so not sure why it’s doing that.. it wouldn’t start back up unless i turned the pole all the way to the left

Put it back on the trailer and started adjusting the lows and highs and idle and was messing around for about an hour and couldn’t get it right. Ran good sitting on the trailer in the water but once i jumped on and got it under load it was just bog and didn’t even want to start most of the time so I’d have to paddle it back to the trailer. Only twice i got t up on plane and the power was really sluggish

Would turning the adjusters in lean it out or make it richer? Also I’ve read threads on guys have the front low at say 1 turn out and the back low at 3/4 turn out, any tips on how to adjust properly cause i though you were suppose to tune hem in sync with each other

For a stock ski just I be running the Br7h? I’m running the br8hs now but I read he br7h is a hotter plug so maybe that will help? It also has the br7h stock for recommended spark plug on my exhaust

You need to read this. This should be a direct link to the mikuni sbn pdf download. You arent going to get a magic fix from a screw turn.
https://www.google.com/url?sa=t&sou...4A_IQFggfMAA&usg=AOvVaw2QsBH3sRn13hBHzxbiuNXH

If its a stock motor etc, it should run just fine on factory specs which includes oem screw positions. The problem isnt that if you are at factory screw setting on all stock.

Turning the screws in makes it leaner. If you are having problems b/t 1/4-3/4 throttle then the screws are not the problem.

Its hard for any of us to advise when you say you think you are having an electrixal problem and you are adjusting carb screws. That shotgun approach doesnt work and is impossible to figure out over the internet with unreliable Dx info.

I think you should find someone local to help you out. Sure paying a shop to do work sucks but you will know andunderstand what was wrong, learn sonething from it and get back a good running machine.