1995 superjet 701 issue

[ejn1214]

I'm hoping someone has some ideas for the issues I am experiencing. It starts up fine, and runs fine for about 2 minutes. It then begins to run at reduced power (maybe 40ish percent power) with no change in speed when full throttle. The engine noise sounds like it normally would at 40 percent power. Within a minute of this it will kill. It starts up fine right away, but it's back to limited power within 20 seconds and then kills in under a minute. You can keep repeating this cycle.

The engine does not seem to be getting too hot, and the pisser appears to be passing water normally.

Things we tried:
-New spark splugs
-New fuel filter
-Ran with air filter removed
-Ran with gas cap removed
-Disconnected gas container vent hose (let remaining 6 inch hose cent directly to air)
-Emptied gas tank and refilled with fresh gas/oil mixture

I plan on running some carb cleaner directly though carburetor. Does anyone have any ideas beyond that?

Thanks in advance!

 

[Kohldanielzimmer]

Check for exhaust leak.

Otherwise sounds electrical (heat soaked stator).

 

[E350]

In our Mikuni SBN44 carburetors there is an internal filter on the side opposite the fuel pump side which gets clogged with deteriorating fuel hose line which in both of our Yamaha skis has caused the very same symptoms. The vent hose sheds black fibers. The fuzzy stuff was incredibly coming from the air intake, past the check valve into the tank and was getting sucked up and caught in the filter inside the carb. I never would have thought that would happen! So I replaced that that OEM air intake line with fast flow fuel line too (blue). Fuel starvation can also be caused by a malfunctioning or backwards installed fuel tank check valve which won't let air into the tank to replace the fuel that the carb is pulling from the tank and into the engine. See my photos of our fuel filter here:

701 Dies when Throttled, Dies at Low Speed, Won't Restart, Then Restarts

Today while riding the FX1, after riding for about two hours, the engine would start, but die as soon as I accelerated. I tightened the battery cables, checked that there was about a 1/2 full tank of gas. Tried to putt upstream to the launch ramp but even at low speed it eventually died and...

www.x-h2o.com

Wouldn't hurt to check those things too in addition to what @Kohldanielzimmer said.

 

[ejn1214]

Thanks guys I will look into those suggestions. I really appreciate the help and time you took to respond.

 

[ejn1214]

In our Mikuni SBN44 carburetors there is an internal filter on the side opposite the fuel pump side which gets clogged with deteriorating fuel hose line which in both of our Yamaha skis has caused the very same symptoms. The vent hose sheds black fibers. The fuzzy stuff was incredibly coming from the air intake, past the check valve into the tank and was getting sucked up and caught in the filter inside the carb. I never would have thought that would happen! So I replaced that that OEM air intake line with fast flow fuel line too (blue). Fuel starvation can also be caused by a malfunctioning or backwards installed fuel tank check valve which won't let air into the tank to replace the fuel that the carb is pulling from the tank and into the engine. See my photos of our fuel filter here:

701 Dies when Throttled, Dies at Low Speed, Won't Restart, Then Restarts

Today while riding the FX1, after riding for about two hours, the engine would start, but die as soon as I accelerated. I tightened the battery cables, checked that there was about a 1/2 full tank of gas. Tried to putt upstream to the launch ramp but even at low speed it eventually died and...

www.x-h2o.com

Wouldn't hurt to check those things too in addition to what @Kohldanielzimmer said.

Just wanted to update that it appears to be fixed. We changed that filter you mentioned (which looked very dirty), and it runs great. You saved me a lot of time and money so thanks so much!

 

[E350]

Pretty much everything I have learned is from having a problem with a ski, then asking here, and people with much more knowledge than me helped me. So, happy to pay it forward to you (for you to pay it forward to others...)

Want to know why (at least why my) in-carb filter was clogged -- so it doesn't happen again?

Believe it or not the culprit was the vent tube hose/line which was deteriorating in the inside then leaking back up and into the fuel tank and then being pulled into the carb by the fuel lines (which I had already replaced).

So, may I suggest that you immediately replace all your lines including the seemingly innocuous vent line!

 

[ejn1214]

Pretty much everything I have learned is from having a problem with a ski, then asking here, and people with much more knowledge than me helped me. So, happy to pay it forward to you (for you to pay it forward to others...)

Want to know why (at least why my) in-carb filter was clogged -- so it doesn't happen again?

Believe it or not the culprit was the vent tube hose/line which was deteriorating in the inside then leaking back up and into the fuel tank and then being pulled into the carb by the fuel lines (which I had already replaced).

So, may I suggest that you immediately replace all your lines including the seemingly innocuous vent line!

Can I use the same type of hose for the fuel line and air vent? What size/ diameter do you use?

 

[E350]

I use Fast Flow Fuel line which is tygone which is what everyone hates on here. But since it is somewhat clear, it has the benefit of allowing you to diagnose fuel problems. You must replace it every 3-4 years because it becomes brittle and subject to breakage which is dangerous. 1/4" line for the carbs. 1/8" line for the primer. I color code, so Orange = Fuel. Blue = Air Vent. I use constant pressure clamps on connections I may remove. Like switching the carb line at the fuel tank from normal to reserve -- my 1/8" primer line is connected to the reserve fuel pick up. (I have bypassed the reserve off on switch.) Otherwise I use zip ties which you can also order from Fast Flow Fuel line. Get a gun like the small one below. I also have the larger gun, but I like the smaller one for working on jet skis. BTW I don't do internal fueling. I have the internal fuel so I can see how much fuel I have when riding and also so I can watch it rise as I fill it from the normal external outside oem fuel tank fill. I have Wax Racing Products' version on our Kawasaki 550sx. He also makes an internal fill for the SJ. @waxhead

1/4

The original Fast Flow Fuel Line. Suitable for jet-skis, snowmobiles, go-karts, ATVs, motorcycles, and other motor sports applications that require a 1/4" low pressure fuel line. Available in Clear, Neon Green, Neon Yellow, Neon Orange, Blue, Red, Smoke, Pink, and Purple. All colors are...

fuel-line.com

1/4

The original Fast Flow Fuel Line. Suitable for jet-skis, snowmobiles, go-karts, ATVs, motorcycles, and other motor sports applications that require a 1/4" low pressure fuel line. Available in Clear, Neon Green, Neon Yellow, Neon Orange, Blue, Red, Smoke, Pink, and Purple. All colors are...

fuel-line.com

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I would like to see what other more experienced rider/wrenchers have to say about this.