the polaris guys didnt have anything to say.

my buddies explorer 300 2 stroke was running fine, then all the sudden there was a nocking sound inside the engine so we shut it off, it will start right up, but still makes this god awful clunking noise, i am going to look at it tomorrow and take it for a spin to see whats wrong any suggestions? broken ring, burnt piston, smashed skirt, i have rebuilt 2 and 4 strokes, do you think i sould pull the jug, and look at the cyclinder, and the rod to see if there is scoreing or looseness, or go with the basics, make sure right octane, and good plug, filter ect.?

 

i wouldnt ride it anymore.i would check the plug and do a compression test.the knocking could be the piston skirts hitting the cylinder.

 

i think i am going to pull the jug off tomorrow, and hope for the best, what i am thinkin is that the skirt is smashed, and hopefully the pieces are not lodged in the crankcase, or it is spliting the case for me, do you think it can just hone, and go .010 over, or a bore, and .020 over, and obivously chamfure the ports. how many pounds should this thing have? around like 170 mabey

 

581, it depends on how loud the nock is. I found a guy on the trail with a polaris that was nocking pretty bad so i pulled him back to his house. He had a polaris 400 explored 2 stroke. The wrist pin at the top of the connecting rod was what was making all the noise. He just put a new one in and it run great now. Now iv got a new riding buddy. By the way the 400 2 strokes are pretty quick. Im neck and neck with a 400 srambler at 300 yards and only get the explorer by about 3 or 4 lenghts.

 

that seems like a cheap fix, thanks guys.