96 GSX Right turn/WOT Cut Out

[jwelch159]

Have been fighting a cutting out issue for the past few rides. Any throttle above about 3/4 will result in a bog. I can hold 3/4 throttle and run at about 5600 rpm. It will jump up to 7k on holeshot for a second or so and the level back down. It will also cut out on right turns. All is well in a sweeping right turn but any jerk and it will cut out.

Things I've done:
-PO replaced grey lines. Ive verified they are in the correct positions
-Cleaned Carbs/little filters
-Replaced fuel selector
-Unhooked red rectifier wire with no change in symptoms
-Richened up HS carb adjustment which made things worse
-Cleaned out main fuel filter bowl, filter looks clean
-All tested with full tank of gas so shouldn't be a pickup issue even though thats what it is acting like

 

[Dr Honda]

Welllllllll.........


you kind of answered your own question. "It will jump to 7K for hole shot, then drop to 5600" AND "Richened up the HS screw and got worse." Your carb is over fueling. Take them apart, and verify everything. I'm guessing the pop-off is low... Needle/seat is big... and/or the return orifice is plugged up.

 

[jwelch159]

I leaned out HS also and no changes. But over fueling wouldn’t exactly explain the right turn situation. I’ll pull carbs again and check jet numbers. It looked like they have been in to before so they could have changed some things

 

[mikidymac]

Did you install new parts from a genuine mikuni kit? Like the plastic check valve, fuel pump check valves, diaphragm? All of these parts can eventually wear out, they are 20 years old you know.

 

[jwelch159]

No new parts installed. Everything inside looked to be in great shape and new. But like I said someone could have changed jetting for some reason which has it screwed up.

 

[jwelch159]

Pulled carbs back apart and all bets are factory spec. Needle levers are adjusted properly. Both carbs are opening fully at WOT. Compression is equal on cylinders. Not sure what else to check.

 

[Matt Braley]

Pop off pressure?

Does your fuel valve hold 5psi? (I'm thinking it doesn't). How about the O-ring in the fuel/water separator, is it in it's groove?

 

[jwelch159]

Didnt have a way to check pop off. But could that even be an issue since the problem is over 3/4 throttle.

I’ve put on a new metal fuel valve. Not sure why it wouldn’t hold.

Not sure where fuel water separator is?

 

[mikidymac]

The separator is under the top deck. Take out the front storage bin and you will see two rivet heads, that’s holding the separator bracket.

 

[jwelch159]

Ok has the little filter in it. It’s all clean. Lines were pointing to starboard side which I rotated it so they would be straight back in case that was attributing to right turn cutout. I just checked it again and there is no oring. but I see the groove you were talking about, I will get one tomorrow and put it in. Don’t have one that big in my set

 

[mikidymac]

It’s a special square o-ring not a standard over the counter one.

 

[Matt Braley]

You have found your problem sir. I'd get the right one though. They have flat sides to them.

 

[jwelch159]

Alright. I have a local guy who probably has some laying around.