96 XP high speed cut out

[Dman142]

Been trying to figure this rig out for the entire summer. Pulling my hair out.
Problem: Initially, it runs and starts very well. At WOT for more than about 5-7 seconds, it cuts out like someone hit the kill switch. This usually occurs within about the first 10-15 minutes of riding and persists. Hard to start afterwards but will start with a quick pull of the choke. Make a few hard turns and it’ll do it again and again. Low end power is great. Seems to get progressively worse as time goes on. Gets to the point you better start heading to the launch.

Attempts to fix:
New fuel lines and filters
Stator-replaced
Voltage Regulator-replaced
Carbs from another machine. No change.
Factory carb settings and adjusted. No change.
Plugs/caps
Dielectric grease on all connectors.
Inspection of each electrical box. No visible issues. No blown fuses.
Cleaned RAVE
Compression at about 145-150

To me it seems fuel related but that has led me nowhere. I gotta try something else.

Couple ideas: Run a separate fuel tank and/or tear into the exhaust and check for some sort of blockage. I have not inspected the fuel system inside the tank yet.

I work on outboards and sleds all the time. Rebuilds are not foreign to me. I know my way around any 2 stroke motor but I’ve been fighting this Doo for 2 years now. I would pay someone to come and fix it even. Been out to the lake over 20 times and everything results in the usual disappointment.

Any new ideas?

 

[Lothsahn]

I would disconnect the red wire on the voltage regulator. I know you replaced it and the stator, but it'd be good to rule out, as that can cause problems at high RPM. That will disconnect stator and regulator. Your battery won't charge, but it should let you rule them out for a quick test.

It sounds electrical to me, except that the choke helps, which makes it sound like a fuel issue.

Thoughts:
Have you replaced or bypassed the fuel selector?
Are your fuel lines touching anything hot? (Vapor lock)
Have you tried a different mpem?
You said fuel "filters". You should only have the water separator. Do you have an inline filter or other filter? Remove those if so...
Do you see any air bubbles or any leaks in the fuel line?
When it happens does it act like the Deadman switch cut out? Do the gauges shut down? Maybe there's a loose connection in that switch?

Where are you located?

 

[Dman142]

After reading pages and pages about carbs acting up, I put a fuel filter before the carbs and after. All fuel lines are intact with no fuel leakage. Through the tygon fuel line, I have seen air bubbles moving about but no idea why as I don’t suspect any leaks, but maybe that’s something to check.

Or maybe the fuel pump pulse line is bleeding air and looses fuel pressure? I doubt it, but I’ll double check.

When it cuts out, sometimes I can revive it without it killing by pulling the choke. On most other occasions, it shuts down totally, just like yanking the key off the post. Stumbles a couple times when restarting i

I did have to bend the tabs inward on the DESS key to make better contact with the post side. Fought that problem this morning.

I believe I’ve bypassed the fuel selection gauge. Did that last year but I’ll check to make sure.

I have not paid much attention to the gauges truth be told.

I don’t have an extra MPM here to try.

Location is northern Wisconsin. If it isn’t sorted out, I’ll get rid of it either by fire or selling as is. Only reason I keep it is the fun factor compared to my other ski—4tec and gp800.

 

[mikidymac]

If pulling the choke helps then it running lean, not electrical.

Remove any additional fuel filters.

Have you replaced the factory fuel strainer and fuel selector?

 

[POPPS]

Did you try bypassing the fuel selector?

 

[Lothsahn]

What Miki said... I bet those fuel filters you installed are restricting flow and you're running lean. You really don't want anything other than the factory fuel strainer. Or the fuel selector has gone bad.

Also open up the fuel strainer and clean or buy an OEM replacement strainer. The aftermarket ones I saw on Amazon don't have as good quality mesh. Also a good time to replace the o-ring in the strainer.

 

[Dman142]

I took out the fuel filters and the water separator for now. Cleaned it out and can reinstall later. Had some black crud in it but the mesh was good. I also bypassed the fuel selector. I’ll go for another test run today.

 

[fatblockabody]

Check on the water regulator in the waterbox as well, it can do goofy RPM related stuff.

 

[Dman142]

Well, I be damned. Removed the filters and went great! Never would I imagine fuel filters used on a crap ton of other motors of all kinds could cause this problem.

I am going without any filter or separator. It hasn’t run this good in about a year. Sure was fun to come in to load up under normal power levels.

I will believe when I can take it out more than 2 times with no issues.

Next up are 2 old wave runners…..all I want it the double trailer under them, but those are not running well either. Just picked them up today from a buddy, flip them, and keep the trailer.

 

[Lothsahn]

Congrats (although I was secretly hoping for a 96xp).

Do reinstall the water separator and fuel selector again. Do one at a time. You made a bunch of changes, so you want to undo them one at a time. The water separator does filter the gas and you want it installed. If it causes you problems consider a brand new one.

Enjoy your toy!

 

[mikidymac]

Just replace the strainer and fuel selector, will be about $50 and be good for many years to come.

 

[Dman142]

10-4. The separator is in good shape with no current blockage. Honestly, I’ll probably just keep it plumbed from the dial switch for now. Sick of working on it so I want to actually use it without limping back home.

I’m secretly hunting for a GP 1200/1300 to replace the 4tec. For the way we ride, the 4tec is just so big, bulky, and the fun factor is reduced. I have a GP800 at the moment that I’ve been using for the last year from a buddy. He never rides it. What newer iron compares to an XP?
Thanks again all!

 

[mikidymac]

If you keep the strainer at least replace the square o-ring that seals it, very common point of air leaks.

 

[1of500]

If you keep the strainer at least replace the square o-ring that seals it, very common point of air leaks.

I suggest keeping one in your tool kit on board a 2 stroke