How to tell if a motor has been stroked?

Is there a way to tell if a motor has been bored and stroked without tearing it down? There is a kz650 near me for sale, owner clames it is done out to 920cc with a stroker crank and over bore. Great buy if the claims are true, if not then I end up with just another kz650 (I am throwing parts away now! I don't need another).

Of course it is not in running condition and the origional owner passed away a few years back, and the reciepts are around somewhere but he can't find them

I smell a scam, but if it's not it would be a hell of a deal!

u would at least have to take the head off, that u can do with the engine in the frame and doesnt take alot of time, then u could measure, the piston size and the amount the piston travels when turning the engine,

I never herd of a stroked crank for a 650. It would need a spacer under the barrels or custom pistons and that's more than the sleeves can be bored so it would need larger sleeves too. Sounds like a scam to m e to.

Mark

take out a spark plug and get the piston up to top dead center take a thin piece of welding rod take a measurement or mark the rod with a marker level with the sparkplug hole and then rotate the motor forward until the piston stops the mark the rod again pull it out and measure the distance between the two marks that will be the stroke.

I would say not likely, 920 now thats custom :laugh:

TB, you so smart.

timebomb33 wrote:

take out a spark plug and get the piston up to top dead center take a thin piece of welding rod take a measurement or mark the rod with a marker level with the sparkplug hole and then rotate the motor forward until the piston stops the mark the rod again pull it out and measure the distance between the two marks that will be the stroke.

damn didnt think of that one , good man

Stroked 650? Doubt that.

yea i checked and didnt get one hit on that term

yes that's why they pay me the big bucks

Hey with enough $$ anything is possiable.... I don't doubt that at some point, someone stroked a kz650. I do doubt this one has been stroked, but if it has been the crank and rods alone are worth the price of admission.

There's another way to check displacement.
You need the plug out, and tdc. use a funnel with a rubber hose that fits into the hole tight. fill er up with oil, and mark the level, then rotate down to bdc and mark again. then you just measure out the oil into a graduated cylinder. Tadah! bore and stroke. Don't forget to blow out the cylinder before you replace the plug.