Upgrading to 161 CC, what about the head?

[JettaKnight]

So I need to pull my current engine and replace it with a older engine that I'll upgrade to 161CC. (long story, I don't want to talk about it)

Since I'm doing this on the bench it's easy to change many parts. Should I stick iwth the stock 125 head, or get a big one? Scooterworks has two heads, which is better?

[Kaos]

So I need to pull my current engine and replace it with a older engine that I'll upgrade to 161CC. (long story, I don't want to talk about it)

Since I'm doing this on the bench it's easy to change many parts. Should I stick iwth the stock 125 head, or get a big one? Scooterworks has two heads, which is better?

The 125 head isn't a bad one, I've got a ported/polished 125 head on my 161.

That being said, either the stock 150 head or the NCY performance head are the two best matches. If you're gonna upgrade the head, you really should do the cam and springs too. Without them, the heads not going to do a huge amount.

[JettaKnight]

So I need to pull my current engine and replace it with a older engine that I'll upgrade to 161CC. (long story, I don't want to talk about it)

Since I'm doing this on the bench it's easy to change many parts. Should I stick iwth the stock 125 head, or get a big one? Scooterworks has two heads, which is better?

The 125 head isn't a bad one, I've got a ported/polished 125 head on my 161.

That being said, either the stock 150 head or the NCY performance head are the two best matches. If you're gonna upgrade the head, you really should do the cam and springs too. Without them, the heads not going to do a huge amount.

Any suggestions on a cam and springs?

Scooterworks has a 58.5 mm and 61 mm head. Is the larger one worth another $30, and will it fit?

[Kaos]

So I need to pull my current engine and replace it with a older engine that I'll upgrade to 161CC. (long story, I don't want to talk about it)

Since I'm doing this on the bench it's easy to change many parts. Should I stick iwth the stock 125 head, or get a big one? Scooterworks has two heads, which is better?

The 125 head isn't a bad one, I've got a ported/polished 125 head on my 161.

That being said, either the stock 150 head or the NCY performance head are the two best matches. If you're gonna upgrade the head, you really should do the cam and springs too. Without them, the heads not going to do a huge amount.

Any suggestions on a cam and springs?

Scooterworks has a 58.5 mm and 61 mm head. Is the larger one worth another $30, and will it fit?

Yes it will fit, but it won't be ideal. Its actually made for the bigger bores than the 161. The 161 kit is 58.5, so thats the head you want.

Any GY6 aftermarket springs will work, though for higher performance double springs are good.

Cam depends a LOT on other factors. JUST installing a 161 kit, head, and cam really isn't going to give you as much performance as they could. There's a lot more tuning that goes into it, and you should really buy transmission tuning parts first. Its no good to make more power if you can't effectively get it to the road.

That being said, if you've not installed ANYTHING other than the kit, head, and springs. An A7, or A8 cam would be in the right range. The stock 150's cam is an A7, and a good choice as well. Be aware that you'll have to swap your current cam sprocket onto the new cam, as regular GY6's use a 34/17 tooth configuration, while the 125's use a 32/16.

[JettaKnight]

Any GY6 aftermarket springs will work, though for higher performance double springs are good.

Cam depends a LOT on other factors. JUST installing a 161 kit, head, and cam really isn't going to give you as much performance as they could. There's a lot more tuning that goes into it, and you should really buy transmission tuning parts first. Its no good to make more power if you can't effectively get it to the road.

That being said, if you've not installed ANYTHING other than the kit, head, and springs. An A7, or A8 cam would be in the right range. The stock 150's cam is an A7, and a good choice as well. Be aware that you'll have to swap your current cam sprocket onto the new cam, as regular GY6's use a 34/17 tooth configuration, while the 125's use a 32/16.

Good to know. I've got a Prima pipe and plan on changing the roller weights and clutch springs and probably the main (contra) spring.