Okay guys I need your help. Atc70 big cam.

[350xx]

I put the racing cam from beatriz cycle in my stock atc70.
255 intake 265 exhaust 6mm lift.
I know the carb on the stock 70 is already way too small for the engine.

Throttle:
0-1/4=good running
1/4-3/4=bogging
wot=YEEEHAAA

Ive tried changing the needle because that is what effects the midrange the most but that didnt do anything.
I leaned the needle all the way out and it still bogs. When i drop the clip all the way down (rich) it bogs a lot more.
Im thinking i need a 16mm carb (http://www.ebay.com/itm/Carburetor-50cc-70cc-90cc-110cc-ATV-quad-bike-dirt-bike-Carb-PZ16-16mm-/260947209184?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item3cc1aa6be0) at least to fix the problem because the cams duration is so high i cant get enough air or fuel through this puny carb.
Advice?

[Vealmonkey]

Carb is too small, but you are asking a stock engine to do alot with a big cam and no other changes, so don't expect alot. To really help the big cam - bigger carb, better flowing air filter and better exhaust. But don't expect a 25+ year old engine to perform miracles with the new cam. Make sure fresh engine oil, adjusted clutch, properly set valve geometry, properly set points, as well as properly functioning wheel bearings front and rear, properly adjusted rear brake shoes and a properly working chain and chain tensioner. A 70 engine doesn't make much power and it doesn't take much drag to really affect the engines performance, cam or not. And once you have a good tune up on the engine, it may be a good idea to run a compression test and see just how tired your top end may be. Ride safe. Have fun. Do it right.

[lndy650]

defenitly need porting an aftermarket or custom stage tuned exhaust and a bigger carb... if you didnt already id defenitly look into hardened rockers and heavier valve springs. and heavier clutch springs..

[350xx]

Thanks for the advice guys!
I may just save up for a lifan in the future.

[350xx]

Im thinking ill put the stock cam back in and go lifan because i dont want to put too much into this little engine.

[lndy650]

Ive done tons of engine work on honda engines but ive never had a lifan I always wondered if they had better porting stock and/or bigger valves ect or if they were better quality... A 200x engine with a redesigned head twin cams and higher compression that would be cool...

[350xx]

Ive done tons of engine work on honda engines but ive never had a lifan I always wondered if they had better porting stock and/or bigger valves ect or if they were better quality... A 200x engine with a redesigned head twin cams and higher compression that would be cool...
That would be worth seeing. It would make a good racer for a teen.