[LittlebikesBigDreams]

had this 40cc 4 stroke chinese bike, swapped it with a cag engine and fabricated this unique motor mount.

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

 

[Atvrunner2]

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.

 

[LittlebikesBigDreams]

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.

 

[kray15]

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.

 

[LittlebikesBigDreams]

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

 

[Atvrunner2]

I don't have any quick threads, just what I learned from reading CAM2 posts. And the experience I got for actually doing it. Let me see if I have pics.
Yes, you taper bore not straight through bore.

A round slide and also a pumper carb oval ported.

 

[LittlebikesBigDreams]

I don't have any quick threads, just what I learned from reading CAM2 posts. And the experience I got for actually doing it. Let me see if I have pics.
Yes, you taper bore not straight through bore. View attachment 162569 View attachment 162570 View attachment 162572 View attachment 162573
A round slide and also a pumper carb oval ported.

appreciate it, i assume you just dremeled that down? then finish the surface smoothly

 

[Atvrunner2]

The pumper carb, yes, the round slide I have a taper drill bit to start, sometimes I finish those with a dremel.

 

[Atvrunner2]

I don't polish it though. I leave just a little roughness after the 100bit sand paper.