I have 92 quadracer 250, and am in the process of
rebuilding the top end, I noticed a lot of side to side play on the crank end of the connecting rod, not up and down play but side to side. This quad has had a bottom end rebuild with a hot rod kit at some point, I don't know if this makes a diference.

 

Direct side to side translation of the rod, where the rod is just sliding on the crank pin is ok as long as it's not excessive as if the thrust washers were gone or something. However, if you can woble the top of the rod side to side without the bottom end of the rod sliding on the crank pin, that means the bearing, pin, or rod is worn.

 

The information that QR gave you is incorrect. The rod can move slightly in this manner and still be ok. Get yourself a service manual. I have a service manual for my Zilla and it gives a maximum allowable "rod rock" as I call it. This has to be measured with a dial indicator gauge which is relatively inexpensive compared to an unnecessary crank rebuild. The tricky part is fashioning a stand that will firmly hold the dial indicator gauge in place while you take the measurement with the engine in the atv.

 

True, there is an "acceptable" limit to rod wobble, but if you can visibly notice it just by moving it with your hand, chances are something's worn. I was writing in general terms mostly to clarify between the 2 different motions I mentioned and also under the assumption that most people don't have digital runout type indicators.

 

I would be wary of the info QR gave you. BTODD is a lot more informed. His advice is sound and he tells you to buy a manual and buy the correct tools to tell for sure. The human eye can detect as little as a few thousands of an inch of movement so just eyeballing it will not give you any kind of reading. I have limited experience with the quadracers, but in general, all rods have movement in them.
I am not putting anyone down so don't get alarmed QR, just stating that you can't diagnose over the internet.