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OK - it's an 04 330 Magnum 2x4 - Pin #4 on the speedo is a kill wire (black wire) - will run disconnected

If you do not have spark, unplug the black wire at the CDI box - if still no spark, replace the stator or CDI box or both.
 

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Discussion Starter #22
I've verified a spark, cleaned the carb, and have gotten it to start once. I used a lot of ether and then it stared a fire in the airbox. Once I put that out I tried starting it again and it backfired and hasn't started again. I've used ether and still no luck. What else can I try. I am about ready to bring it to the shop.
 

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You could have fouled the plug with the starting fluid. Try a new plug and see if it will start and pick up fuel from the carb. If not then like Latebird said, it's probably too low on compression to pull fuel into the engine. Test compression and move forward from there.
 

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Discussion Starter #26
compression is at 0. I am going to do a rebuild but, I don't know the oversize of the piston. There is no option to purchase a rings without an oversize.
Any tips?
 

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You could just have the decompression stuck, rings stuck or worst case, the cylinder and piston are shot. As it happens I have an OEM cylinder already bored .020 over with a new piston and rings. Came off a 2005 330 engine. If you go that way, you can just remove and replace the cylinder and piston. PM me if you are interested. Otherwise, you are going to need to pull the cylinder off, take it to a machine shop and have it measured. The measurements will determine how much oversize you need to go. Cylinders get barrel shaped when they wear out. Most places will want to measure the cylinder and get the piston themselves. I usually pay about $125 for the top end kit and another 50 for the machine shop.
 

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I just re-read this entire thread and did not see where you checked the valve adjustment - before you start dismantling the engine (or as part of the dismantling process) check the valve adjustment - verify the valves have clearance and recheck the compression with the throttle wide open (or carb removed from the holder) - if still no compression, continue the dismantling to find out what the problem is.
 

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Good point. The valves will tend to get tight as the machine ages so you could have a valve being held open affecting the compression. I would think there would be something on the gauge though.
 

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If it sat for a long time a valve might be stuck open - in that case there would be massive clearance on the valve - a clearance check will reveal something.
 
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