taotao hellcat 125cc upgrade, help

[Price995]

ive got a taotao hellcat 125cc and im trying to upgrade the cc in it to 180cc. the engine number is 154fmi. ive googled and all ive got was bore kits for gy6, im looking for a 180cc bore kit with the diameter of 54mm, can anyone refer me to where i can get one. thanks.

[wheelbender6]

I don't think bore kits that large exist for the horizontal 125. You will probably need to purchase a larger horizontal engine.

[dirtbkr188]

I don't think bore kits that large exist for the horizontal 125. You will probably need to purchase a larger horizontal engine.
That's correct, and putting a 54mm cylinder on a 125cc horizontal engine only makes it a 131cc. Normally, a 125cc engine has a 52.4mm bore and a 57mm stroke.
As wheelbender stated, you'll need a YX150 or YX160 engine as the base for adding a big bore kit to put you up in 180-ish cc range, as seen here (https://tboltusa.com/store/tbparts-170cc-to-184cc-bore-kit-and-28mm-carb-kit-for-the-yxgpxzongshen-engines-p-2289.html)

[wheelbender6]

Piranha, Zongshen and others offer a 190cc cub engine.
https://tboltusa.com/store/piranha-190cc-2v-five-speed-electric-start-engine-p-10932.html

[Price995]

thanks guys, another question, if i just want to make the bike go faster in general is buying another engine the only way i would have to go. right now the bike go about 50-55, im wanting it to get up to around 75. what would i have to do?

[cheesy]

thanks guys, another question, if i just want to make the bike go faster in general is buying another engine the only way i would have to go. right now the bike go about 50-55, im wanting it to get up to around 75. what would i have to do?

Well, other than putting it in the back of a pickup...a shot of nitrous...maybe cubic dollars...

Sorry, couldn't resist.

Changing the gearing is your only other option, say 1 tooth more up front or one tooth less in the back to start, but there are trade offs. What you gain in top end, you lose in acceleration and 'grunt'. Grunt is a way of saying that a hill you climb easily now at speed, will require you to downshift to maintain that same speed up the hill. And a headwind may keep you in a lower gear.

[wheelbender6]

For the cost of a piranha engine, you could probably buy a good used Hawk 250, but I don't think it will do 75mph either without serious mods.
To do 75mph day in and day out, you probably need a CSC RX3 or SG400.

You sure you want to do75mph on 14" tires?

[Falkon45]

A Lifan 150cc could be a good option. After, gearing, and a carb and exhaust upgrade, you should be able to hit somewhere near those speeds. But, I really wouldn't recommend that. If you have to hit those speeds, I'd look into a different bike.

[TominMO]

OP, even with optimal gearing, my 200cc Lifan X-pect was not capable of a sustained 75 mph. And as said 14" tires are gonna be unstable at that speed. Forget it and get a different bike.

[Falkon45]

It's on 12" wheels. And, some really built groms can hit that speed. It's not really a good idea, but can be done.

[TominMO]

It's on 12" wheels. And, some really built groms can hit that speed. It's not really a good idea, but can be done.Yeah, 75mph with 12" tires means you better have some pretty good racetrack skills.

[Falkon45]

https://www.youtube.com/watch?v=N88jvgctNaQ

14:58 in the video. apparently, the worlds fastest grom, converted to 2 stroke. lol.

at 18:16, there's another one with a horizontal engine. lol.

[Falkon45]

and then, there's this death trap. And FZ-07 swapped grom. lol.

The first half of the video is the explanation of the build. Rides start at 9:48

https://www.youtube.com/watch?v=7dgNjv0w5cc

[Emerikol]

You can solve any problem if you throw enough money at it, but unless you just want to do this as a thought experiment just to say you did it, I'd keep this bike as a round-town-runabout, and invest in another motorcycle for your 70-75mph trips. Trying to daily such an unconventional setup will just leave you frustrated and pissed off on the side of the road. That's my two cents' worth, your mileage may vary.

[Big Bird]

There is no BBK for the hellcat that I am aware of. It has a different cylinder height than the Boom bikes which can make use of the 141cc bore kit. To comfortably hit 75 you would need to do a zs190 swap which is very common on these bikes.