Hey guys, I'm wondering if anyone has any advice or dealt with a similar issue. I have a 2002 Savage, owned for about 10 years. It ran great last fall when I put it away for the winter. When getting it out this year, it won't run right all of a sudden. The issue has changed a bit but now I'm stuck with it doing the same thing. The first time I started it, it would idle but as soon as you gave it any throttle it would die. The issue now is that when its cold, it'll fire right up but idle/run erratically. You can rev it up but it won't be completely smooth and will misfire here and there. The longer it runs, the more erratic and rough it gets until it eventually misfires more and more and then stalls. It won't run for more than about 5 or so minutes total. After that, it'll be very difficult to start again, if it'll start at all. If you let is cool down for a while or come back the next day, it'll start right up again and do the same thing. I have cleaned the carb 6-8 different times making sure everything is clear. I've also rebuilt using a genuine Mikuni rebuild kit with new needle and seat. I've cleaned the tank out thoroughly and converted the petcock to the Yamaha conversion and added an in-line fuel filter. New spark plug. I have 2 different OEM coils that test within spec and have tried both, same issue. I have ohmed the green/orange wires coming off the CDI and it is within spec based on the Clymer manual. I have tested spark after it dies and has cooled for a bit by pulling the spark plug and grounding it against the engine. The spark looks yellow/orange to me. I've tested for vacuum leaks while its running and have found nothing. I've hooked up a timing light while the bike was running to see if the spark is consistent and you can see it missing and such. Does anyone have ideas on what else to look at? I'm thinking its an electrical/spark issue but I'm stuck at this point. Thanks for any input.

Thank you for the suggestion and I will double check. The battery is a Duracell AGM that was brand new late in the season last year. I just assumed it was good for that reason, but it wouldn't be the first time a new battery has failed pretty quickly.