CB300RL Engine

[XLsior]

Found this on Alibaba.


Zongshen/Zonshen ZS175FMN

300cc, 4 valve,6 speed, counterbalanced, Estart.


https://www.alibaba.com/product-deta...67791.html?spm

[culcune]

Originally Posted by XLsior

Found this on Alibaba.


Zongshen/Zonshen ZS175FMN

300cc, 4 valve,6 speed, counterbalanced, Estart.


https://www.alibaba.com/product-deta...67791.html?spm

I believe a few members got one of those a couple years back. One member had a long-ish thread in which they stuck one in a Hawk. That being said, the 300's that a few members bought, might not have been that 175FMN engine.

The brand Dongfang is offering a 300cc 173FMN engine in a dual-sport and it is even street legal in California (a big deal since California has much stricter state emission standards than the federal US government). However, I cannot seem to find specs on how many gears its transmission has (5 or 6).

(example)
https://www.360powersports.com/dongf...-street-legal/

[XLsior]

The other 4 valves I've seen forum users posting were not counterbalanced 6 speeds...

[Dusman]

I put the 2 valve version of that engine in my Hawk (PR300, counterbalanced, 6 speed). It runs like a champ and outperforms most Honda CRF300Ls I’ve seen. I’ve got over 5,000 miles on it now with zero issues: https://chinariders.net/showthread.php?t=33557

There was a fellah on the Templar FB group that was trying to sell that 4 valve head to people with my engine, but he wanted upwards of $500 for the whole head package if I remember correctly. I thought that was highway robbery.

[Thumper]

Techncally, it is probably about a 285cc engine. With a 75mm bore, it would have to be a 68mm stroke to have 300cc displacement. If it is the more common 65mm stroke, it calculates to 287cc. But the four valve head has to breathe much more easily! It probably has more torque earlier.

I got an Otom big bore cylinder kit claiming 300cc for my 172FMM (249cc). It turned out to be a 265cc kit. With a ported head and cam, it would probably be worth all of the trouble of installing the cylinder/piston kit, even with a 2 valve head!

Either way, the liquid cooled NC300 would stay cooler on the trails. You can add a fan to the radiator to make sure the heat doesn't get out of control!

[Mumen Rider]

Originally Posted by culcune

I believe a few members got one of those a couple years back. One member had a long-ish thread in which they stuck one in a Hawk. That being said, the 300's that a few members bought, might not have been that 175FMN engine.

The brand Dongfang is offering a 300cc 173FMN engine in a dual-sport and it is even street legal in California (a big deal since California has much stricter state emission standards than the federal US government). However, I cannot seem to find specs on how many gears its transmission has (5 or 6).

(example)
https://www.360powersports.com/dongf...-street-legal/

That's a five speed and a PR250(zs172) going off of it's physical appearance and the fact it's got the 14kw rating and not the 15kw rating that a PR300(zs175) would have.

Originally Posted by Dusman

I put the 2 valve version of that engine in my Hawk (PR300, counterbalanced, 6 speed). It runs like a champ and outperforms most Honda CRF300Ls I’ve seen. I’ve got over 5,000 miles on it now with zero issues: https://chinariders.net/showthread.php?t=33557

There was a fellah on the Templar FB group that was trying to sell that 4 valve head to people with my engine, but he wanted upwards of $500 for the whole head package if I remember correctly. I thought that was highway robbery.

I know who you are talking about, it was $450 shipped but I think he has since lowered the price for the package to $350.

Originally Posted by Thumper

Either way, the liquid cooled NC300 would stay cooler on the trails. You can add a fan to the radiator to make sure the heat doesn't get out of control!

The NC series of engines have completely different mounting points than the ZS172 series of engines. It would not be worth the amount of modification for a 2-4hp gain over a water cooled NB300 that would bolt right into anything that came with a counter-balanced ZS172/175. You can skip the water cooling and just buy a NB300-F which is an air cooled NB300. Or if you have a ZS172/175 that's two valve just swap in a TYX300 that will bolt right in(including head mount), make more power than a 4 valve ZS175 and have an oil filter.

[Thumper]

I had not seen the NB300. I see it on Alibaba now. Looks great! But I've been burnt before (fortunately, only ~ $120 shipping), and won't buy from there or AliExpress if it is more than $10-$15 for things like mirrors, lights... And this was with AliExpress intervening and insisting I get a refund. But only after I had to pay for return shipping. I did get the refund for the item, but not the shipping. That was NOT how the original sale was posted. In fact, I had promise from AliExpress that shipping WAS the responsibility of the seller, untill the email disappeared (before I copied and pasted it for proof). I never got my shipping refunded. We hear about items not clearing customs, or items not as advertised pretty often on this website. I don't know why but these things happen.

[XLsior]

I just find it interesting how the tech is hybridizing and progressing...


I anticipate the 350cc class is just around corner (actual 300cc)



the CG150-200 cc is mostly gone now.



it's nice to know more options are available in the off chance a new engine is desired.


Yes I've been stung by Aliexpress a few times but most disputes have resolved in my favor.
Though I've only ever purchased things that I could cover a loss on...


Never tried an Alibaba and 1 crate motor + shipping isn't exactly cheap. However If I had connections to an importer or could strike up a bulk order with a few other people it could be a less risky consignment.