What?! My 2021 Kayo T4 223cc Bike is really a 250!

[Rooster]

I have been searching for the displacement markings on this bike for a while. I finally found them on the back on the engine under the bottom cooling fin. I was hoping to see a 230cm3 because I had heard the newer bikes went up to a 230 from a 223cc. When I pointed a flashlight at it, there it was. 250cm3!

I thought this bike felt pretty zippy for a 230cc bike. No wonder, it's a 250!

I am curious what happened. I know they have some different dual sport 250cc models that I have not seen exported to the USA. Also they have the 250cc engines that they put into the K2, K4 models. Did they run out of the smaller engines mid way through the bike? A mistake? Not sure but I sure am happy about it!!

As a side comment. This also shows that you can change out the 223 engines with a 250. They fit in the bike.

[franque]

It might be stamped that it is a 250, that doesn't mean that it is. You should take a picture of the motor by the shift shaft and post up what that says. It should start something like ZS1**FMM or similar.

[Rooster]

Originally Posted by franque

It might be stamped that it is a 250, that doesn't mean that it is. You should take a picture of the motor by the shift shaft and post up what that says. It should start something like ZS1**FMM or similar.

Whoa I though that displacement stampings were always correct.
Will do on the photos. Are you saying that they could have rounded a 230 up to 250 for the stamping or that they used a 250 case with 230 internals?

[stewbrash]

The engine identifier is more than likely correct. I'm not real sure but it's something iike the ZS172fmm is the 249cc and the ZS165fmm is the 223.6.

Here is parts for a 223cc for sale on Aliexpress...down below it lists engine specs:https://www.aliexpress.com/item/4689...4%239976%23443 Also, further down is a picture of a head...and it shows 250cm3...but says 223.6 in the specs.

Here's a zs172fmm 249.9cc on Alibaba:https://www.alibaba.com/product-deta...1c76713bgtHAxY

[franque]

It happens from time to time. In Europe they'll sell you some 'cheater' big bore cylinders that are stamped with the original cylinder's displacement instead, e.g. 124cc for a 150cc cylinder. The code on the engine side is more reliable, but even that is fudged from time to time. A picture of the code and the whole engine will tell more.

[Rooster]

Thanks so much guys! Mine is the LX166FMM. My manual has it listed as 233 for the displacement. Could that be the difference between the 165FMM and the 166FMM? The 165 being 223cm3 and the 166 233cm3? Or maybe just a misprint?

[Rooster]

Originally Posted by stewbrash

The engine identifier is more than likely correct. I'm not real sure but it's something iike the ZS172fmm is the 249cc and the ZS165fmm is the 223.6.

Here is parts for a 223cc for sale on Aliexpress...down below it lists engine specs:https://www.aliexpress.com/item/4689...4%239976%23443 Also, further down is a picture of a head...and it shows 250cm3...but says 223.6 in the specs.

Here's a zs172fmm 249.9cc on Alibaba:https://www.alibaba.com/product-deta...1c76713bgtHAxY

Thanks for the info. The specs on the engine you linked there says it has a displacement of 232.6 cm3 listed in the overview. That is close to the manual for my bike that says 233.

[ghostdancing]

in the motor code, the first number (1 in this case) means single cylinder, the other 2 numbers after the first, are the bore in mm: for example 163 means single cylinder with 63mm bore; 172 means 72mm bore (and it's the 249cc motor)

note that looks like all these motors have the same stroke (62,2mm??) or at least i read this info somewhere in the web

the letters after the numbers also have a meaning: for example FMM means air cooled (F), motorcycle motor (firstM) 250cc (second M)

i learned these intersting things on a russian webpage (thanks to translator, of course); i posted the link in my " what motor for a honda XL200frame" thread

[Rooster]

That's awesome! Thanks so much. So that means that a 166 would have a slightly bigger bore / cc than a 165. Maybe a 10cc difference as my manual suggests? That would make sense with the slight raise in the cc's documented with the newer bikes.

[stewbrash]

Yeah, I saw that also, I think somebody (who's dyslexic) just transposed the 3 and the 2 because if you look further down, there is a chart that lists the specs more accurately at 223.

[stewbrash]

While pretending to b working, I found this page for you Rooster.
https://www.aliexpress.com/w/wholesale-lx166fmm.html

[Rooster]

Thanks!

[franque]

The strokes vary a little bit, there are 125s with the classic Honda 49.5mm stroke, some that copy the 57.8mm of the XR/L 185-200, some with the 66.2 of the CRF230, and more commonly the 62.2 of the XLR/CTX 200 (not USDM models) for most 200cc models and *some* '250s'. The 172FMM-3a has its own at 61.4. it really depends on the motor, and ultimately what it measures out to. I have a presumably 163FML (based on certain measurements without popping it open) that is marked 167FML. You really can't be certain without opening it up and measuring it, but I'd leave it as is unless you're really stricken by curiosity.

[Rooster]

Looks like this one is a 223. I found one on ebay with the specs:
Bore x Stroke：65.5 X 66.2mm
https://www.ebay.com/itm/25487285559....c101110.m1982

[Megadan]

The T4 should have a 169fmm engine, 69mm bore x 62mm stroke. GPX Moto sells a replacement engine for what is essentially a rebranded T4 under their name. The 169fmm and 172fmm are the newest generation of the ohc "CB" clones.