2008 Baotian BT49QT-28B - Tauno49cc (I SOLD IT!)

[90GTVert]

Yeah, you can't really just slap a carb on and expect it to work unless maybe it's exactly the same.

[Scootrific]

That is the point, where I learn some new stuff. It is my first time to do that cind of work

[Scootrific]

I did try run it without airbox, but the rpm´s went very high. I decided to leave the racing reed valves and put the original carb back. To see if that makes any diference. I hope I can ride home today

[Scootrific]

I posted the same problem to my country scoot forum and there, one guy sayd that I have to change the jet to smaller one. Original carb is 14mm and that has main jet nr.62. The racing carb, that I tried has main jet nr.95. I tought, maybe I take the 62 main jet from old carb and place it to new carb? Or not?

[90GTVert]

I'm guessing 62 will be too small. 95 prob too large since it revved high without the airbox. I'd use the old carb till you get a jet kit.

[Scootrific]

vlatx told me in one of his post aubout jet to use - I think it was main jet 80. But I will buy the jet pack. maybe next month or when I get some stuff sold for my so called SCOOT FUND. I wish, that someone buys my pc, then I can place that money to my Scoot Upgrades.

I did calculation, and all the parts, that I have buyed and need to buy + the cost of my scoot = NEW STOCK APRILIA Street SR50

[90GTVert]

That's how it works with pretty much anything you customize unless your primary focus is budget. It's easy to get wrapped up in these things.

[Scootrific]

At the Estonian scoot forum, one user told me to put the needle clip to middle position and try jets between 70 and 80. I checked the needle, and it was already at middle.

[Scootrific]

90GTVert, Do I have to adjust the needle clip position too, when I change the jet 95 to jet 80.

This is the needle clip position now on A2 needle:

[90GTVert]

Not necessarily. If you find that it runs rich or lean from say 1/4 up to 3/4 throttle, then you may need to adjust the needle position.

[Scootrific]

I was wondering. The main jet 95 was too big for the new 17,5mm carb, so I brought jet no.80 (5 mm). When I change the main jet from 95 to 80, do I have to change also the pilot jet?

The other thing was - can I use the main jet 62 from original 14mm carb, if the jet 80 does not work or it will be too small for the 17,5mm carb?

[90GTVert]

You're taking big leaps here. Generally you're better off to go maybe 5 numbers at a time (so say 95 to 90), 10 at most if there's clearly a need for a big swing, 2-3 when you're close.

There is no need to swap the pilot jet just because you swap a main jet. Pick the main jet that works best 3/4-WOT. Try to get the idle up to maybe 1/4 throttle in tune with the mixture screw. If you can't, then swap the pilot jet and redo mix settings. Select a needle position for good transitions with the throttle and good performance from roughly 1/4-3/4 throttle. There is no sort of x main jet must be used with x pilot jet and x needle setting. They should be selected individually for their appropriate functions.

[Scootrific]

OK. One of my friend told me, that he´s going to sell his scoot - It is the Aprilia on my first post on this thread. I am thinking, maybe I will buy it from him and sell my Baotian scoot. Before that I will tune my scoot to work with the 17,5 mm carb.

[190mech]

The Aprilla is a good scoot,but parts are very costly..They had 3 different engine types too,which one does it have?The fuel injected models have their own unique problems also..

[Scootrific]

I do not know. It looks like that: