Huasheng 4 stroke feels restricted..?

[4banger]

I searched the forum and haven't seen anything describing my issue. Help if you can

I know my engine/bike setup can get faster than 23mph. It has before comfortably hit 28+ alittle on decline with my old engine, exactly the same setup. If anything it should be similar speed with more power since I have a lower gear 40tooth hub and the dual chain trans opposed to the single chain trans with 44 tooth hub previously.

What it does at 3/4 throttle hitting 23.5 mph is start to "gurgle", if you will, and top out there. More thottle just makes a more consistent gurgle and adds no more speed or power, just tops out at 23.5mph. It feels/sounds like the gurgle is more on the exhaust side of the engine.

I thought maybe my old carb, which had the fuel-air mix scew unplugged was adjusted more appropriately or had a different jet. But when I put it in the engine stalls out around 12mph. Any adjusting failed to improve that,so I put the new carb back on.

My main question, yet open to advise and suggestions, is the symptoms I'm having, are they cause lack or excess fuel, or is it suffocating and need more or less air? Doesn't seem like valve cleaence to me, engine runs smooth. I've been told that these 5g Huasheng aren't governed but idk maybe? Is my poopoo flex exhaust choking me out? I'm stumped. Help if you can, please and thanks.

If it helps heres specs.

-HS 5g straight shaft 142f kit from bike berry.
-Stock dual chain trans from kit.
-40tooth rear hub adapter bbtuning.(direct drive)
-stock carb.
-bb tuning flex poopoo motocross exhaust.
-26" schwin Delmar cruiser.

...old build was exactly the same with these differences...
-HS tapered shaft 142f
- stock exhaust (stock exhaust had same issue in new build btw)
-single chain 4g trans direct
-44-tooth pineapple rear assembly

 

[Dan]

Hey 4B.

"gurgling" Trying to imagine what that would be? (sorry typing out loud)

I'm sure you played with choking, what does that do for you? Just since you mentioned it, have you tried with muffler removed just for a bit? Would help rule out too much back pressure.

Honestly, I am not great at helping via text. I'm fair to midline with em. Just not great at helping threw words. Really need to hear and feel an engine. But some folks here will amaze ya at how quick and well they pick up and can help. I was kinda avoiding it but saw you were still waiting for some input.

Oh, did ya use the in-tank fuel filter? They can be restrictive.

LoL, still stuck on trying to figure out the gurgling. That's one of those, wakes ya up at 3am and "GOT_IT" sorta things.
(I hope)

Lemme know how your making out...

 

[CrazyDan]

You've changed your gear ratio swapping transfer cases. You'll need a much smaller rear sprocket to get your old speed (and lower hill climbing capability) back.