2006 Baotian BT50QT-9D - (SOLD) - Scootrific

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I wonder, if I use 98 fuel main jet, and 58 slow/air jet. Is this config fine for 72cc engine with 20mm carb?

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Almost had crash again

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Yesterday, I went for a long ride and after that, I got my GoPro Hero4 Black. Made a side by side video to to compare these 2 cameras. Sena10c was 1080p and the GoPro Hero4 Black was in 4K. But this video is Part 1. At home, I played with some setting on my GoPro. That wideo will come out soon.

Part 1 :

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Now, I made the Part 2 to the previous video. Before shooting that, I tweaked some settings on GoPro Hero4 Black.

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CVT cleaning and clutch swap. The variator thingy, where the belt is riding, this would not come out. That got some heat and needs swaping in near future.

Video (on the bakround, there is my Lada VFTS project):

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I think that, I found the cause of vibration, on my scoot´s CVT. The bushing on the variator, where the belt is on. That was not round anymore, it was stuck on the variator housing, and did not move out of his place. Tha cause of that thing was the heat produced by the CVT. That´s my theory. What do you think 90GTVert .

[90GTVert]

I don't know exactly why they get out of round, but bushing issues can certainly cause all sorts of problems.

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I saw a Jay Walker on the road:

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90GTVert I swapped the variator and the vibration is back now. I think, it is caused by the crankshaft side, that the variator rides on, it is wobbling. I heard, that this was a common problem, for these Chinese scooter engines.

I brought an crashed Baotian. The sale notice had pics, with engine on. But when I went to buy the scoot, he told that he forgot to tell me, there is no complete engine (only frame and some parts). So I brought it anyway (with 60€), with all included parts: frame with gas tank, front shocks and fork, both wheels, original exhaust, some plastics. Maybe I build an trailer, from that frame or something. Like my one friend made a joke - " You have a welder and tools to make stuff, so build a trailer for your scoot "









Plan A:
I went online and did search this 12" engine, and found one too. Only thing is, that I have to take all necessary parts, from my 10" engine, and put these parts to the 12" rear wheel version. Also I have to buy some new bolts, nuts, 12" CVT cover and complete cylinder kit, with heads and big valves. Maybe I go for the 90cc kit, that costs about 238€. If I buy everything, on my list, that I could need for that scoot upgrade, then it will be set me back by about 1000€.

Plan B:
The second version, is to by brand new complete 50cc engine (about 450€), and then take it apart. After that Upgrade it to 90cc.

[90GTVert]

Plan C:
Piaggio two-strokes are bottom mount.

Now that's a good use of a welder and tools.

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Hey, 90GTVert. Now I have some engine issues, with my scoot.

Baotian BT50QT-9, Naraku 20mm Carb, with 90 Main Jet and 62 Idle Jet. CVT has Polini Speed Variator, with 5g weights + Polini Kevlar Belt + Naraku 2000rpm Torgue Spring and Sport Cluch.

Info about that problem: The Scoot went about 20km/h and no more. The sound was, like in this video, rpm´s were 3000-3500. Before, was the scoot running fine and went over 70km/h. I placed new fuel filter, with new hoses. Did a Carb swap. With the old carb, the sound was better, but I do not remember, what was that carbs issue. Also, I noticed, that the new air filters Intake side was broken. ... fixed that and tried with the old carb. One point, the fuel was coming out from the air filter. Then I swaped back to new carb and the sound was the same - banging and stuff. I also broke the sparkflug pipe. Then I took an Lada 21063 sparkplug wires, and made new detail. Maybe the timing is bad ore Carb Jets. Now I do not have kickstart system too. I got hurt, by trying to get the spring back to his place.

Today, I tried to get that scoot running, with the old carb (same as the new 20mm one.), and fuel was pooring out of the air filter.

Video, of that strange sound:

[90GTVert]

If fuel is pouring out of the air filter, the float height is probably way high or it's stuck. You aren't going to get it into tune that way and even if you could, the fuel overflow would need to be corrected ASAP.

It's either really rich or the ignition system is weak in the vid.

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Aug 5, 2019 11:42:12 GMT -5 90GTVert said:

If fuel is pouring out of the air filter, the float height is probably way high or it's stuck. You aren't going to get it into tune that way and even if you could, the fuel overflow would need to be corrected ASAP.

It's either really rich or the ignition system is weak in the vid.

If the " the ignition system is weak", then I think the problem is with the Magneto (on the right side of the engine). That is dirty, need to clen it. But I will check the carb issue again (the float height thing).

[90GTVert]

You can use an adjustable gap spark tester or bend the strap back or cut it off of and old plug and use that to create a larger gap for the spark to jump for testing. Those will tell you more than just making it jump a standard plug gap.

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Aug 5, 2019 12:27:33 GMT -5 90GTVert said:

You can use an adjustable gap spark tester or bend the strap back or cut it off of and old plug and use that to create a larger gap for the spark to jump for testing. Those will tell you more than just making it jump a standard plug gap.

I´m not going to trouble myself, with looking up the engine issue, on my BT50QT-9D. I found an 80cc brand new engine for 450€. I simply will do a engine swap. From that old 139QMB engine (72cc), I will take spare parts to my other scoot, that I brought recently. That Baotian BT49QT-20C, has 4-Stroke engine, with Racing parts and 90cc.