Coloradotrailrider,
I would really like to get an official answer from Lifan or who ever made these engines, that way we know what bore and stroke we have and what parts would fit. Maybe "ssgt tanner" can give us some bore and stroke measurements and we can go from there. It is my understanding also that the 71 in 171FMM indicates bore size which would be about 71x58.5 for 233cc. I will pass along anything I find and hope others will do the same to help solve this mystery engine......................Slydog

 

the stroke 55.7mm my friend checked it with a meter

 

Thanks ssgt tanner, but what about the stock bore ? thanks for the info........Slydog

 

We checked stok 72x59.2 is stok my new is 73x59.2
the firt measurements were rong the strok isnot 55.7

 

SSGT Tanner said in a previous post that the bore was 72mm, they had the head off to port and polish it.

 

Thanks SSGT Tanner, that gave us a final measured bore and stroke of 72mm X 59.2mm, we difinatley now know that we have a displacement of approximatly 241cc with an online calculator.

 

Who makes the HI BIRD ? dont split the motor it is a nightmare

 

We are playing with Hi BIRD 250ST this bike was a lot of problems it has no power
it is unstable . the shocks are a joke

 

Thanks ssgt tanner for the info. Here's a link to the emission's info badge on a 2008 Hi-bird that shows 18.1hp and 248cc ! Don't really know what to trust but it does say it is manufactured by Hi-bird motorcycle. Some good info on the badge either way, but in their description it says 67x65mm bore and stroke, so that would be 229cc and the emissions badge clearly says 248cc. So with some math if ssgt tanner bore it out to 73mm then in theory 73x59mm would give you about 248cc and that might be what the 2008 Hi-bird has, just a bigger bore. Links below for everyone to read.
Here's the badge link......http://i262.photobucket.com/al.../slydogsrus/badge.jpg

Here's the auction link..... http://cgi.ebay.com/eb...ors.....genameZWDVW

</a>

Here's a link to Chongqing Hi-bird Industry Group in China..........
<a target=_blank class=ftalternatingbarlinklarge href="http://www.hi-bird.com.cn/English/showart.asp?art_id=10
">http://www.hi-bird.com.cn/Engl...t.asp?art_id=10
</a>

Slydog

 

This one is a peace of crap it das not got that much power no way to speed is 40mph
andthet is pushing it