When you say considerably....how's that exactly. Unscrew your sparkplug cap from wire going to the coil, clip it just a cooch hair and re-screw in the cap to assure you have a good connection there. I have a cousin who was having damn near the same problem with his LT250, he dicked with it, several shops messed with it, no one could figure it out. I did just what I stated to do above & whallah! No problems with it since... I'm not saying that's the case, just something to try if you haven't already. And yes, make sure you have good grounds and all electric connectors are tight.