What would be causing this?

[Trooper182]

Ok so trying to figure this out. My issue is when I launch from a dead stop my GTX will rev to 5k and then hang there before slowly building up to 6500rpms. Then sometimes it will snap all the way to 7k and feel like it is cavitating. Wear ring was replaced by the previous owner before I bought it. Ring and impeller look great with no Knicks. Tolerances are in spec. I also replaced the carbon ring. Max speed I can get is 49mph on gps and 6540rpms. Carbs have been rebuild with mikuni parts along with new needles and seats. New fuel lines/filters/selector valve. Popoff is at 30psi.

 

[GGuillot]

What are your needle settings? Try new plugs properly gapped? How do the RAVES look? Water valve on the muffler functioning well?

 

[Trooper182]

What are your needle settings? Try new plugs properly gapped? How do the RAVES look? Water valve on the muffler functioning well?

Both low speed needles are 1 turn out. Mag carb is 0 and PTO is 1/2. Plugs are new and gapped correctly. I pulled the raves 2 weeks ago and cleaned them again. Water valve is new. Had to replace it about a month ago.

 

[POPPS]

Is the regulator charging?.,is the stator putting out before the regulator.,,,..try running the inline directly from the fuel pickup into the carb,,,that will also help you rule out upstream fuel delivery issues.