2017 Ultra LX engine issue

[ab197331]

Hi All,
I have developed an issue with my 2017 Kawasaki ultra LX (40 hours on the clock) where the engine stumbles / surges at part throttle where it feels as though the fuel is being cut from the engine, at a frequency of around 2 to 3 times a second. The launch is fine, then around 30km/h - 4000-6000 rpm, the engine stutters more aggressively than a misfire, and will continue until I back off slightly or apply more throttle. Full throttle is unaffected. Most of the time after experiencing the issue the engine will return to a higher than normal idle speed, around 2000 rpm, instead of the usual 1300-ish. A shutdown, key removal and restart fixes the idle speed. I have replaced the spark plugs without success.
I will attempt to attach a couple of recordings of the issue to demonstrate.
Any ideas?
Cheers, Andrew

[ab197331]

https://share.icloud.com/photos/0fcidb--YeSc6wr23DEwj_QRg

[ab197331]

https://share.icloud.com/photos/017Y_JhLMUi1U8JlevI_k1Vew

[steve45]

Welcome aboard, ab197331!

Can you post this someplace where we don't have to download it to see it?

[ab197331]

Welcome aboard, ab197331!

Can you post this someplace where we don't have to download it to see it?

ok, will give it a try. Any suggestions on the easiest way?

[steve45]

YouTube

[ab197331]

YouTube

Ok, cheers. YouTube links below:

https://youtube.com/shorts/oXY9RS0hhg0?feature=share

https://youtube.com/shorts/nwAWZeJNDng?feature=share

[steve45]

That's better!

I really don't have a clue. It would seem that it would run badly at higher power settings, but it sounds like it takes off quite well. I would guess that you might have water in the fuel.

[Cranofwaterfell]

Could be fuel pump going out. One of my 300 LXs sounded like that. I rigged up a fuel pressure gauge in line between tank and fuel rail, you could see pressure dropping from 40 to <20 followed by engine sputtering like yours.

[Hurricane1000]

I have a new Ultra 310R oem fuel pump..

If your interested.

Dave

[Cranofwaterfell]

I might be interested, what are you asking for it?

[ab197331]

That's better!

I really don't have a clue. It would seem that it would run badly at higher power settings, but it sounds like it takes off quite well. I would guess that you might have water in the fuel.

looks like you were right Steve. Water in the tank. I have drained all the fuel and mopped up the water from the bottom. Is it worth putting some methylated spirits in with the next tank full to help pick up any remaining water? Should I be cleaning the pump too?

https://youtube.com/shorts/Zpe1pEzg-s4?feature=share

https://youtube.com/shorts/OnPq8NWyBRg?feature=share

Cheers

[steve45]

Glad you found a problem. It appears that your model does not recirculate fuel back to the tank, therefore, I would try to clear the lines by removing the plug at the end of the fuel rail and cycling the fuel pump on and off several times to get any remaining water out of the system. Use some sort of container to catch the fuel and inspect it for water.

After you turn the 'Ski on with the Immobilizer key, the pump should come on for a couple of seconds. Just bump the start button to turn on the fuel pump again, if needed. Replace the plug.

Hope that solves the problem!

[ab197331]

Glad you found a problem. It appears that your model does not recirculate fuel back to the tank, therefore, I would try to clear the lines by removing the plug at the end of the fuel rail and cycling the fuel pump on and off several times to get any remaining water out of the system. Use some sort of container to catch the fuel and inspect it for water.

After you turn the 'Ski on with the Immobilizer key, the pump should come on for a couple of seconds. Just bump the start button to turn on the fuel pump again, if needed. Replace the plug.

Hope that solves the problem!

Cheers for all the info Steve. Fuel is back in the tank and primed clear. Will let you know how the water test goes.

[ab197331]

Cheers