250cc 4 valve Grom Clone

[warrenpeas]

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.

[delzy]

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?

[warrenpeas]

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

[Bruces]

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 .

[Thumper]

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

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

[warrenpeas]

Originally Posted by Thumper

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

4 valve zongshens are WATER cooled.

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

here he disassembles the top end.

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 .

here he compares the zs172fmm-6 to an older 2 valve version? zs172fmm-?

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.

[warrenpeas]

Originally Posted by Thumper

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

4 valve zongshens are WATER cooled.

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.

[delzy]

Originally Posted by warrenpeas

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.

OK, I just pulled the trigger on the 4-valve 250. There is also a 4 valve 300, but it appears to have a funny exhaust angle, so I thought 23hp would be enough. The 300 is the
Zongshen NB300-F

Someone should try this out.

[delzy]

Originally Posted by delzy

OK, I just pulled the trigger on the 4-valve 250. There is also a 4 valve 300, but it appears to have a funny exhaust angle, so I thought 23hp would be enough. The 300 is the
Zongshen NB300-F

Someone should try this out.

Total fail... 5 months later I'm getting a partial refund. I am ordering the ZS172FMM3a for 19 HP instead of 23..

[Mumen Rider]

Originally Posted by delzy

OK, I just pulled the trigger on the 4-valve 250. There is also a 4 valve 300, but it appears to have a funny exhaust angle, so I thought 23hp would be enough. The 300 is the
Zongshen NB300-F

Someone should try this out.

Chongqing Hengzhijia Bearing Co., Ltd. is the worst supplier on Alibaba to deal with, they tried fucking me over on a damaged shipment that was missing items.



The NB300-F is the air cooled version of the NB300, kind of a "rare" engine with regards to Chinese bikes. I have only seen it on Russian and Chinese market bikes. It's different from the CB250R/300RL series, it has an actual oil filter.

Originally Posted by delzy

Total fail... 5 months later I'm getting a partial refund. I am ordering the ZS172FMM3a for 19 HP instead of 23..

Did you use CQHZJ on Alibaba? They don't bother to package the boxes correctly.

Yongkang Yiton Mechanical & Electrical Co., Ltd. has packages engines the best from my experience so far, they fill every void with Styrofoam inside of the box and then wrap the whole box in tape.



Guangzhou BAWO Trading Co., Ltd is really slow to ship but their packaging was okay but I might have just been lucky.

[warrenpeas]

Originally Posted by Bruces

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 .

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.

[Thumper]

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:



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!).

[warrenpeas]

Originally Posted by Thumper

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?

[ProDigit]

I doubt a 300 will fit, but it might. Some YouTuber put a CBR300R engine on a Grom. So you never know.
Personally, I think the Sweet spot is between 175cc and 200cc.
You still get good fuel economy, especially if it's a higher compression engine, tuned well, but also a lot more torque and top speed than the 150.


I'm wondering if it was a plug and play, or did you need to weld any mounts?
From the space I see inside that bike, I probably would want a size smaller engine.

Originally Posted by warrenpeas

... what should the operating temp be?

Most engines run between 180 and 212F, this due to them being water cooled and 212F is the boiling Temperature of water.

[warrenpeas]

Originally Posted by Thumper

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!).

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