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Seized 2-stroke

3K views 13 replies 12 participants last post by  fouillard13 
#1 ·
Hey all, I'm about to pull the motor from the RD250 frame and I took the heads off to see what was stopping the motor from turning. Well, the pistons are definitely locked to the cylinders. It looks like it could be just from rust. I'm hoping that if I can remove the pistons and jugs that the bottom end will be salvageable. Anyone have a trick for getting the jugs free? So far I've been soaking it with WD 40 and letting it sit. I'm going to try knocking them loose with some wood and a hammer, but am open for any suggestions.
 
#7 ·
As strange as this sounds if it is a rust seizure, pour a regular red label coke into each cylinder. There is enough phosphoric acid in the drink to loosen and eliminate rust but not enough to score the piston or cylinder. I have freed up a couple of engines using this method. You may have to let it soak a couple of days but it will free it up. Then GENTLY tap the pistons with a plastic dead blow hammer or a piece of wood. If it wasn't heat seized, this should work. I know I am way late entering this thread but this is good info for anyone facing this problem.
 
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