Which BBK Is Right For Me?

[lykos23]

I've come a long way in attaining high speeds on my stock 63cc scooter, but it's about time for doing that popular thing that's equivalent to compiling your own linux kernel in the world of scoots; a BBK install.

I've been watching lots of youtube videos on the procedure, I've been reading up on the results, and I'm perturbed by the contrasting opinions. Some people say that too much of a bbk will ruin internal parts and etc. Others say that anything less than 72cc isn't worth installing. And while I know there is no true 100cc kit, what cc exactly is the 50mm bore kit?

I need my bike to last, but I also need my bike to go 45mph+ just to reach my bank. Right now 40mph is my top speed at 63cc and I've done all I can in regards to variator weights, clutch springs, performance coil, carb jetting, and all the main necessities so I think it's time to up the engine power.

I've got a Peace Sports 50, 2009 model.


I plan on getting this exhaust http://www.amazon.com/gp/product/B00A2OJ5R8/ref=ox_sc_act_title_2?ie=UTF8&psc=1&smid=ABXFT02JRY7L for when I install the bbk, because I've read horror stories that a performance exhaust will ruin a stock engine unless it has enough power to push all the air out of the exhaust.

So which bbk is the right one for me?

Right now the following are in my cart and I'm not sure if any of them are good or which one I should really get:

http://www.amazon.com/Scooter-Bore-72cc-QMB139-Stroke/dp/B0043X28S2/ref=sr_1_6?ie=UTF8&qid=1369438091&sr=8-6&keywords=47mm+big+bore+kit

http://www.ebay.com/itm/GY6-Scooter-Big-Bore-Kit-72cc-Emission-Head-including-performance-camshaft-/390542353461?pt=Other_Vehicle_Parts&hash=item5aee236435&vxp=mtr

http://www.amazon.com/gp/product/B00CYSE40S/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A1NHCW6NW9A2EP

http://www.ebay.com/itm/100cc-Big-Bore-Kit-Cylinder-Head-Piston-Rings-Scooter-139QMB-GY6-Engine-70002-/290910381530?pt=Motorcycles_Parts_Accessories&hash=item43bb9c25da&vxp=mtr (http://www.ebay.com/itm/Chinese-Scooter-Big-Bore-Kit-100cc-50mm-Bore-64mm-Valves-QMB139-Scooter-Parts-/321093898987?pt=Other_Vehicle_Parts&hash=item4ac2b012eb&vxp=mtr)

http://www.ebay.com/itm/Gy6-engine-80cc-big-bore-kit-139QMB-moped-Chinese-scooter-performance-upgrade-/111067240051?pt=Motorcycles_Parts_Accessories&hash=item19dc1f9673&vxp=mtr



I eventually plan on getting another scooter just because I like toying with these things, would I be able to take my old 63cc piston and bore and install it in a different 49cc 139qmb for a cheap little bbk upgrade?

This thread has helped me in my decision to get a bbk:
http://scootdawg.proboards.com/index.cgi?board=4strokeissues&action=display&thread=21571

[lykos23]

I think I found the perfect kit!

http://www.amazon.com/Scooter-Bore-72cc-QMB139-Stroke/dp/B0043X28S2/ref=sr_1_6?ie=UTF8&qid=1369438091&sr=8-6&keywords=47mm+big+bore+kit

Mainly because it comes with a performance camshaft. Unless somebody else has some opinions by the time I order it, around the first weekend of next month.

I'm really tempted to get that 50mm bbk, but I read horror stories of people breaking things with so much power, and even though 72cc isn't much of an upgrade from 63cc I think it will give me just enough umph to reach my goal of 45mph. Plus I won't have to change anything with my carburetor other than maybe the main jet, I think.

Unless I find some preventative measure I can take to increase the longevity of my engine with a bigger bbk I think I'm going to get this one... I sure hope the performance exhaust will work with such a meager bbk, haha.

[buford1488]

you got to talk to millsc on here he can help you alot.....contact scrappydogscooter.com...thanks..buford

[lykos23]

you got to talk to millsc on here he can help you alot.....contact scrappydogscooter.com...thanks..buford

Yeah, Millsc is pretty great at this stuff. I've tried looking through scrappydogscooter's bbks but they don't have quite as much of a bang for buck as the ones on ebay and amazon have. I mean, one of them comes with a camshaft for the price of just the bore and piston on scrappydogscooters. Their other products and prices are great though.

[fieromoped]

I tried almost every bigbore kit on a 50cc moped, I finally broke down and installed a 150cc, I DO NOT REGRET IT :) I will provide pics on another thread, But its a short case install and the moped looks just like a stock 50cc, Sleeper :)

[inuyasha]

I tried almost every bigbore kit on a 50cc moped, I finally broke down and installed a 150cc, I DO NOT REGRET IT :) I will provide pics on another thread, But its a short case install and the moped looks just like a stock 50cc, Sleeper :)
Hi
Welcome aboard
Pleased to meet you
Have you registered and tagged it as a 150 since you changed it? and do you have your motorcycle endorsement? if not your riding an illegal scoot and are opening your self up for possible legal problems
Take care and ride safely
Yours Hank

[lykos23]

I tried almost every bigbore kit on a 50cc moped, I finally broke down and installed a 150cc, I DO NOT REGRET IT :) I will provide pics on another thread, But its a short case install and the moped looks just like a stock 50cc, Sleeper :)
Make sure to listen to Hank's advice.

I finally installed my 50mm bbk and it's plenty of power for me :nod: Just for the heck of it I'm installing a few more performance upgrades and then I'm good to go. Go 50mph that is.