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Discussion Starter · #1 ·
had this 40cc 4 stroke chinese bike, swapped it with a cag engine and fabricated this unique motor mount.
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first time ever mig welding, not bad for a clueless 15 year old. I took a generic cag exhaust and have a neighbor who builds systems for a living expand the chamber 2 inches and shorten the header….
i plan on porting the exhaust port and transfer ports….. port the stock carb to 14-15 mm too and mess with timing . going to try and maintain og cag tuning tips. for the culture ;)
 

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What's your poison? Mine is 40:1
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Nice looking good!! I definitely slowed down building as I have switched to gopeds for a while. I still have 2 cag engines to finish.

Did you test fit the exhaust to make sure it won't hit the tire?
Also the carb, don't go all the way through, just the front needs opening. If you go all the way through the piston in the carb will not be big enough and cause an air leak, and make sure to do the petcock mod.
Keep it up and spread you projects to friends.
 

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Discussion Starter · #3 ·
Nice looking good!! I definitely slowed down building as I have switched to gopeds for a while. I still have 2 cag engines to finish.

Did you test fit the exhaust to make sure it won't hit the tire?
Also the carb, don't go all the way through, just the front needs opening. If you go all the way through the piston in the carb will not be big enough and cause an air leak, and make sure to do the petcock mod.
Keep it up and spread you projects to friends.
i pre fit the exhaust before the added inches and it seemed like i had plenty of room all around to pull it off. if you have any golden threads you may have stickied on carb porting that would be appreciated . i have read around and i got the idea but visuals are always helpful.
 

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With carb porting, creating a venturi is more important then just making it larger. If you simply bore it out larger it will slow down the air speed which will reduce the amount of fuel going into the mix. I can't think of any threads off the top of my head. Its been a while since that has been discussed.
 

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Discussion Starter · #5 ·
With carb porting, creating a venturi is more important then just making it larger. If you simply bore it out larger it will slow down the air speed which will reduce the amount of fuel going into the mix. I can't think of any threads off the top of my head. Its been a while since that has been discussed.
got it, i’ve got a couple old threads from like 2007 . will post pics when i get around to it
 

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