Big Bore

[AlexisStarlyn]

Hey guys, I want to get a big bore kit for my 2012 Agility 50 4T, I know there are a lot of boards on this, but I wanted to check and see if there is new stuff that has changed and other such things. Also where to find a good one for my scooter!

Thanks in advance!


Sqk

[blue]

If you do the big bore change out everything that gos with it not just the head. I have seen so many do a half a_ _ job.thinking this will work. Other wise just get a bigger bike. I had my 50 cc agilty doing 48 to 50 on a good day and 35 to 40 up hills. with out the big bore. Not doing things right will bend your crank.....So replace the crank to.to a stronker one .

[dude]

Hey blue, what kind of setup were you running before you did a bbk?

[ThehardcoreFTW]

Top speed =/= power.
A big bore kit vastly enhances your torque and therefore your acceleration. I could get up to those speeds (speedo, definetly not true speed) with my 50cc as well, but only on nice days with no wind and a smooth road.
With my big bore I can drive at the top speed practically whenever I want, tucked in, with or without wind, smooth surface or cobble road, doesn`t matter anymore. I also pull out in front of the cars at a light what makes my commuting time shorter.

[JJJoseph]

Hey guys, I want to get a big bore kit for my 2012 Agility 50 4T

I've used standard Chinese qmb139 BB kits in my Kymco, and they all seem to work OK.  Why I say "all" is that I've blown up my engine twice while scooter racing at night, and my last experiment took out the crankcase.  That said, my experience with Chinese racing parts has been pretty positive.  For one thing, they're really cheap, and the quality is excellent. The kits work OK on NON-fuel-injected 50cc KG10/KG20 models.  I haven't checked if they fit the fuel-injected models. There's a couple of provisos: the 80cc BBK adds power, but top speed doesn't change much unless you unrestrict the CDI and swap the final drive gears.  Also, some BBKs come with a cylinder head, and your stock exhaust may not fit. I'm also using a racing cam (more mid-range power); you can also get 4-valve heads, which I'm not using.  A tachometer is recommended.

[c.stroe]

Hello everyone,

I am riding a Kymco Like 50 4T. It is basically the same engine as the Agility 50, however there is no dedicated forum on my scooter.
Has anyone considered the upgrade to 70cc?

I am considering 2 upgrades and I do not know what to choose:
1) First option is to go with the following products:
- unrestricted CDI: https://www.racing-planet.de/cdi-power-kit-unrestricted-for-kymco-like-agility-city-rs-50cc-4-stroke-p-236447-1.html?backcPathco=14&cPath=26_11792

- variator: https://www.racing-planet.de/variator-malossi-multivar-for-kymco-50cc-4-stroke-p-100059-1.html

- 70 cc kit: https://www.racing-planet.de/cylinder-kit-naraku-v2-72cc-for-gy6-kymco-50cc-2v-p-101917-1.html?backcPathco=16&cPath=26_11792

2) Second option is to for a full Naraku package:
- unrestricted CDI: https://www.racing-planet.de/cdi-unit-naraku-unrestricted-for-kymco-like-agility-super-8-4-stroke-p-243918-1.html?backcPathco=14&cPath=26_11792

- variator: https://www.racing-planet.de/variator-naraku-55g-for-kymco-4t-sym-139qmb-qma-p-101547-1.html

- 70 cc kit: https://www.racing-planet.de/cylinder-kit-naraku-v2-72cc-for-gy6-kymco-50cc-2v-p-101917-1.html?backcPathco=16&cPath=26_11792

What would you recommend?
Unfortunately, by the time I decide what to buy, the products are no longer available on the Racing Planet European website :-(

Regards,
Cristian.

[JJJoseph]

The 47mm (about 70cc) BBK is a good place to start.  You won't get much speed change unless you also change the CDI: https://www.aliexpress.com/item/PERFORMANCE-Adjustable-CDI-Unit-DC-DERESTRICTED-Fit-KYMCO-AGILITY-SENTO-PEOPLE-50cc-125cc-150cc-4T-SCOOTER/32811023290.html

and the final drive gears: http://www.ebay.com/itm/49-17t-Performance-Final-Drive-Gears-GY6-139QMB-Chinese-Taiwanese-Scooters-/182619874928

There's hundreds of different CDI choices, and most of them are duds, difficult to start, etc.  The one shown works well (available from several sources).  You don't have to change much else to get a good performance increase.  If you've got the time and energy, you can also add a race cam, sport exhaust, sport air filter, light-weight rollers, etc. for small additional gains. It's possible to get almost 75 km/hr (48mph) from these basic mods.  Trying to get more will just blow up your engine. The entire engine can be replaced for less than $250, but it's a hassle, and you have to start all over again.

[c.stroe]

Hi Joseph,

In fact, I want to get maximum 70 kmh out of my scooter and just a little bit of more power when accelerating from a stand still position. In my country (Romania) you do not have many places where to buy scooter parts and there not a lot of engineers or specialists to advise you on what to buy, what to install.

I was wondering whether somebody has had any experience with Naraku parts.

Best regards,
Cristian.

[JJJoseph]

My experience is far away from Romania, but I'm aware that Ukraine & Russia have lots of scooter users, and good Chinese parts are available in Russia, especially in the south like in Crimea and Sochi areas.

[c.stroe]

Joseph, how many hours shouldI expect to be charged for installing a new CDI, performance variator and 72cc kit? I have receive an offer from a local shop totaling 5 hours. That would probably cost as much as the parts.

[JJJoseph]

A new CDI takes about 10 minutes, the rest of the work takes me about 8 hours, so 5 hours by a professional mechanic is reasonable.

[blue]

I did not do the bbk I just did cvt tuning and bigger carb and cut the cdi .And got 48 to 50 out of it.