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Old 07-09-2020, 02:37 PM   #1
RenoHal   RenoHal is offline
 
Join Date: Jul 2020
Location: Reno, Nevada
Posts: 1
New BBK I stalled. Tuning confirmation

Hello everyone,

I just signed up to the forum and want to say hi!

I installed a 100cc BBK on my qmb139 no brand tao tao knock off and the difference in power is just amazing. However, for some reason, I'm having problems getting the tuning down, I think. I guess it would be more like I just want to make sure it's good. I'll just list how I have everything and if you have any ideas and/or suggestions I would certainly appreciate it.

I set the valves to .004 (both intake and exhaust)
I installed a 95 main jet in the carburator but I had gas spewing out the exhaust so I put a 90 and that stopped. Took out box air filter and installed foam filter. It doesn't seem like it gets any hotter than it used to when it was just a 50cc and it runs like a dream. I've adjusted the fuel mixture on the carburetor, but I think I have to mess with that some more as there's about 10 seconds after the idle drops down from a cold morning start that it wants to almost die. After the 10 seconds, it's fine. I'm having trouble reading the spark plug just from a lack of experience. I've taken the scooter to work and back about 4 times (about 5 miles each way). Here is the spark plug:

IMG_20200709_073408374_crop_20_compress91.jpg

Polish_20200709_095249949_compress61.jpg

If there is a problem with the pictures, please let me know as I'm trying to do this on a phone.




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Last edited by RenoHal; 07-09-2020 at 02:39 PM. Reason: Want to make sure pictures are good
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Old 08-02-2020, 11:45 AM   #2
Fahqu2   Fahqu2 is offline
 
Join Date: Mar 2020
Posts: 29
Quote:
Originally Posted by RenoHal View Post
Hello everyone,

I just signed up to the forum and want to say hi!

I installed a 100cc BBK on my qmb139 no brand tao tao knock off and the difference in power is just amazing. However, for some reason, I'm having problems getting the tuning down, I think. I guess it would be more like I just want to make sure it's good. I'll just list how I have everything and if you have any ideas and/or suggestions I would certainly appreciate it.

I set the valves to .004 (both intake and exhaust)
I installed a 95 main jet in the carburator but I had gas spewing out the exhaust so I put a 90 and that stopped. Took out box air filter and installed foam filter. It doesn't seem like it gets any hotter than it used to when it was just a 50cc and it runs like a dream. I've adjusted the fuel mixture on the carburetor, but I think I have to mess with that some more as there's about 10 seconds after the idle drops down from a cold morning start that it wants to almost die. After the 10 seconds, it's fine. I'm having trouble reading the spark plug just from a lack of experience. I've taken the scooter to work and back about 4 times (about 5 miles each way). Here is the spark plug:

Attachment 1172

Attachment 1173

If there is a problem with the pictures, please let me know as I'm trying to do this on a phone.



What kind of scooter? With valve adjustment sounds like a 4 stroke. So it’s dying after the auto choke goes off? Maybe the idle jet needs to be upped, but I would adjust the idle higher to see if that fixes it.
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