Need some guidance on repairing a scrambler. Purchased 2000 Polaris Scrambler 400 for my son since he outgrew his 50 cc. The quad was just off idle and stalled, locked the engine up. Pulled the cylinder to find the piston skirt opposite the exhaust port broke into pieces. Case and cylinder appear to be undamaged. However, the pieces of piston have stop most of the crank/rod movement. The crank can be rocked slightly. Is there any do’s/don’ts from you pros before I start disassembling the engine removing the piston pieces…

Thanks!

 

the stock oem piston is crap,it need to be remplaced with a wiseco,it is now a biased trend to be fixed,
put a top end bearing and polaris gasket back in,and it will last longer than ever if you take care of it at warm up.

 

as long as it didn;t run long after the skirt fell ou may be able to get away with a bottom end flush in diesel fuel. but I did this when my skirt went out and the crank bearings lasted less then 6 months. now about 1.5 years latter I need a new crank becuase my rod bearing finally went.

just something to think about.

rittercycles does great work and has more experience with this engine then any other.

 

The same thing happened to me but the piece out of the skirt went down into the crankcase and put a hole in my crankcase.