how to measure or test for cc's

[DesertDog]

Anyone know how to test an engine (4 stroke) single cylinder for what cc it might be.
dont think mine is a 250cc, say's on the stamped plate a 239cc, i know that means a 250cc, but in all it does'nt have the power of a 250 i think,
it could be alot better i think for a 250cc, the engine in it is a Loncin with a 4spd trny, so any clue to what or how to test ????
desertdog :?:

[warrior91]

bore x stroke

[TeamCheap]

what warrior91 said.

I dont think these chinese engines are tuned anywhere near the top end of their potential performance.

maybe they make them that way so they last a little while or maybe to give the best chance of running for the most people or maybe to cover their substandard quality.

That 4 speed tranny has to be a bit limiting I'd think.

The honda 300ex I have can wheelie at will and it is an old tired beat up machine 282cc though.

Your making me even more excited about trying my 200cc-GY engine in my blaster frame.

[DesertDog]

bore x stroke
so how do you measure bore&stroke, what tools do i need ?

[DesertDog]

what warrior91 said.

I dont think these chinese engines are tuned anywhere near the top end of their potential performance.

maybe they make them that way so they last a little while or maybe to give the best chance of running for the most people or maybe to cover their substandard quality.

That 4 speed tranny has to be a bit limiting I'd think.

The honda 300ex I have can wheelie at will and it is an old tired beat up machine 282cc though.

Your making me even more excited about trying my 200cc-GY engine in my blaster frame.


1. i'm glad for you , give your self a pat on the back

[katoranger]

bore x stroke
so how do you measure bore&stroke, what tools do i need ?

Special ones. Dial indicators and you will need to remove the head to measure the cylinder.

Allen

[DesertDog]

:?: limited info means i'm in for a real treat, i'll have to ask the tech guy at the yamaha shop,
thanx for the help

[katoranger]

I know that the engine number translates into a cylinder diameter. You can sometimes measure the stroke through the sparkplug hole.

Allen

[TeamCheap]

TeamCheap wrote:
what warrior91 said.

I dont think these chinese engines are tuned anywhere near the top end of their potential performance.

maybe they make them that way so they last a little while or maybe to give the best chance of running for the most people or maybe to cover their substandard quality.

That 4 speed tranny has to be a bit limiting I'd think.

The honda 300ex I have can wheelie at will and it is an old tired beat up machine 282cc though.

Your making me even more excited about trying my 200cc-GY engine in my blaster frame.


1. i'm glad for you , give your self a pat on the back
I'm glad :D for me also "pat pat" and very glad :D that your glad :D for me so were all glad :D together and its a glad :D glad :D world. :roll:



Click on this link SILLY this will help you but you still need to give it the RIGHT info (http://www.csgnetwork.com/cubicinchcalc.html)

[DesertDog]

:?:
you'll have to excuse me i get alittle testy when i dont get my rest.
i dont want to take it aprt without knowing or having some kinda knowledge from the pros at china riders, thats all.
if i can do this i will know whether or not my distributor ripped me off (go figgure that one).
so be cool us old cusses are'nt full of it anymore :wink:
if you go to my gallery i've put some pics there , not good ones but its a start, desertdog last page in the gallery
:roll: buh-bye

[BoY860]

never thought you could test for cc when they say 250cc there sayin the dimensions of the engine measured in cubic centimeters usually china bikes will never give you the right answer which really sucks but not much to do about it

[coloradotrailrider]

Hey DesertDog, bore X stroke is correct. To find that information first look at the number on the left bottm side of the engine, it should say somthing like 171fmm. The '71' in 171fmm stands for the bore size. To verify the stroke you can remove the spark plug. Find a clean thin rod of somekind that will fit through the hole. Put the piston to the very top of it's stroke. Put the rod in the hole and let it rest on the top of the piston. Make a mark on the rod at the top of the sparkplug hole. Now turn the engine by hand till it is at the bottom of it's stroke and make another mark on the rod. This will be your total stroke. You can turn the engine by hand by removing the small starter cover on the left side. If you remove the gear set thats in there you can turn the smaller gear thats in the side case with a prybar. Find an online calculator to convert your measurments. Here are a few pics. If it is a 171fmm that 238cc sounds about right. I went through this before and it comes out to about 238 - 241cc. As far as power it is all in the gearing.

A quick low end power change can be accomplished by changing the front drive sprocket down a tooth or two in size.
http://i267.photobucket.com/albums/ii285/Coloradotrailrider/engineRed.jpg
http://i267.photobucket.com/albums/ii285/Coloradotrailrider/250startergear.jpg
http://i267.photobucket.com/albums/ii285/Coloradotrailrider/Startersidecoverbolt2.jpg

[DesertDog]

some what of good info on cc's

http://www.dmv.org/how-to-guides/motorcycle-ccs.php

[warrior91]

Sorry for the limited info D.D. , but I personally think that anyone who wants or proffesses to be a dealer should really know something as simple as how to determine c.c's...
Not being ignorant , but that is my 2 cents...if a nudge won't do it, don't ask me to push!
Kato told you exactly what the last post took you through...but without the handholding....

I am not trying to be short....just blunt. :?

[DesertDog]

just sharing articles as i find them , and am waiting for loncin to send my products to complete an engine,
share all yur blunt thoughts none are rejected

but if thats all you've got "give up"
thats my 2.3% worth 8O

[coloradotrailrider]

Come on guys, I thought this forum was all about owners of Chinese bikes helping each other and sharing what we know. :D