hey everyone, i'm hoping you can answer a few questions for me. this last weekend my sled quit, a '99 670 h.o., with 4100 miles on it. i can not get the sled to run now. the sled will fire briefly for a second then die, almost like it's starving for gas, however the plugs are wet and i sprayed ether in the cylinders and still only a quick fire. i compression tested both cylinders, both were respective with a 135 lb reading. now, when you pull the sled, it sounds like there is no compression down in the crank. is it possible that the center seal went on the crank. when i pulled the plugs again, there was smoke coming from both cylinders, and if you blew down one cylinder hole, smoke would come out of the other. i thought that these were seperate cylinders and that shouldn't happen. or could it be something to do with the rotary valve maybe? how hard would it be to replace the seal on the motor, i'm sure you would have to remove the motor and split the cases correct? anyhelp would be great, you people have always helped me out in the past, thank you bj

On my daughters, she blew a belt which then rapped itself around the crank and took out the crank seal.

Geez, I'm not sure on this one, but pretty sure the cylinders should be independent of each other, otherwise you'd have mixture problems. Unless it's going through the exhaust ports when you blow into the cylinder?????

The center seal went out in an old jag we had years ago. it was completly and totaly dead- it did not fire at all. i would start by checking out your electrical system maybe? sounds like it could be a shorted out key switch/kill switch. I've had keys go bad, and short out to the off position. they display similar symptoms as you have... ie, try to fire but just won't.

good luck

- Jason