250cc 4 valve Grom Clone
 

Hi im in the south Kansas City area

This is a Condor 150cc swapped to the Zongshen "CB250r" 250cc 4 valve engine. Complete build price after i insall the wideband AFR gauge and the new cluster is about $2800 but i sold the 150 motor brand new for 400$. The idea was to create something more reliable and less expensive than the Daytona/zongshen 212cc 4 valve. This motor cost me $560 and i know the ZS212cc 4v is around $1100.

https://www.youtube.com/shorts/DFqqaxOrgqE

I will be happy if it can hit 90mph with the 17/31 sprocket setup.

Nice project. 90 on a mini! WOOT, WOOT!! I just picked up one of these recently and I'm almost done building it into a stunt bike. I'm sticking with the 150, but I replaced the carb with a tunable PZ27 and the exhaust with a KPT200 pipe and a slip-on muffler.



I just joined up so I'll probably document my build. I'm coming out at a total around $2500 total. Can you tell me more about that exhaust you have?

exhaust
 

the pipe is from aliexpress listed as kpt200 exhaust. the slip on is from amazon. https://www.aliexpress.us/item/32568...Cquery_from%3A

What’s up with the engine ?the name on the side of it looks like zonsen ,is it a clone of a clone or are my eyes failing me faster than I think ?
I have no interest in these bikes but it would be a lot of fun wringing it out .

4 valves ?!
 

Nice swap! but Whoa,whoa, whoa. That is a 2 valve engine, isn't it?

4 valve zongshens are WATER cooled, aren't they?

Zongshen is the name of the founder i guess they have changed their name to Zonsen Industrial Group Co., Ltd https://en.zonsen.cn/. I dont know whay they put Zonshen vs Zongshen on the side but i know if you order more than 10 i think the number is they will put whatever you want on the clutch cover.

no its 4 valves. rated t 23.4hp but i guess 19.5 at the wheel on the dyno according the the russian video below.?

turn on closed caption and change the setting to english to understand what the hell they are saying.

here is the video of the 4v head https://www.youtube.com/watch?v=zazakTXrAFw

here he disassembles the top end. https://www.youtube.com/watch?v=ygNu07IzJSc

here is the video of the dyno test vs the zs172fmm-6 vs a 172 2 valve i think and explain the power band difference https://youtu.be/64LZdA7TjEM?si=A0C98RyYl6hb4s6r&t=1862.

here he compares the zs172fmm-6 to an older 2 valve version? zs172fmm-? https://www.youtube.com/watch?v=JBeUd-BnGPE

i just found these videos earlier today before work and havnt had time to watch them all and read everything they said but it is informative.

when i was looking for ths motor i was tlaking to a seller in China i had bought zs190 horizontal engines from. i told him i wanted the most powerful Vertical AIR COOLED 4 stroke engine he could sell me and this was it he told me. although i wonder if there might be a more powerful 300cc option after looking into it more. Oh and i was trying to keep the price under 1000$ delivered. I paid $560 for this delivered to my door. in comparison the zongshen 212cc 4 stroke horizontal motor is $1080 delivered.

Amazing! Very cool. I like it !!!

I FOUND it. Yes, the ones I found appear to be 5 speed. I see the gear position diagram has 1-N-2-3-4-5 in the decal on the stator cover:

Attachment 30695

I saw "Zongshen" on one red valve cover photo. I wonder if Zonsen is another pirated logo, or just a different Zongshen logo. Could be made by Zongshen.

Heat could be an issue depending on where you are driving and how hot it is out. You would want wings focusing air through that head if you are riding off road (slower speeds, more work!).

im using an oil cooler. the oil going in is at 145F and out at around 205F after 20 minutes idle. im adding an oil temp gauge soon. what should the operating temp be?

this guy says the engine can have overheating issues so he added ports to the head cover for his oil cooler. He is using the motor in a dirt bike im using it in a street bike.

now there is a 300cc version with the 4 valve head and counterbalance ZS175FMN with 6 speeds. actually according to the bore and stroke calculator it is only 271cc

my motor literally has this decal on it i dunno what i was thinking.

You have a rare engine there, and fitting it into the Grom clone must have taken some deft engineering. Very cool.

it actually bolts right in the rps condor 150 because it already uses a cg150 upright engine.