I've been riding 2-stroke MXers for almost 25 years and never encountered this before.
Started my bike yesterday (early 80s CR250) just before the start of my vintage moto. Everything seemed fine, then the bike died. When I tried to restart it, it was clear that the compression in the motor was drastically low. There was some resistance to the kickstarter, but not much. The bike ran fine just earlier in the morning and on the way to the start gate.
The piston seems to move smoothly up and down the bore with no nasty noises, but it won't come close to firing. Head and base gaskets seem OK. Nothing looked wrong when I took a look through the exhaust prot after removing the pipe.
I'm going to tear it down this evening, but has anybody experienced a sudden loss of compression like this? I'm guessing (afraid) it's a stuck or broken ring.
Started my bike yesterday (early 80s CR250) just before the start of my vintage moto. Everything seemed fine, then the bike died. When I tried to restart it, it was clear that the compression in the motor was drastically low. There was some resistance to the kickstarter, but not much. The bike ran fine just earlier in the morning and on the way to the start gate.
The piston seems to move smoothly up and down the bore with no nasty noises, but it won't come close to firing. Head and base gaskets seem OK. Nothing looked wrong when I took a look through the exhaust prot after removing the pipe.
I'm going to tear it down this evening, but has anybody experienced a sudden loss of compression like this? I'm guessing (afraid) it's a stuck or broken ring.