two days ago the 780 did something weird. about 20 minutes into my drive, the tach dropped to 0, but engine was still running at the same rpm, like i had just took my foot off the gas. nothing happened with my foot on the gas. then the tach jumped back up and i could accelerate again. happened a couple times then stopped. it's happened a few times since then, all when i'm doing about 40-60, and once it goes through its cycle it doesn't do it anymore until the next time i drive it. i searched through FAQ and haven't seen anything. there is a lot of oil on the engine because of crankcase/broken pressure switch, so i cleaned the grounds thinking it might be an electrical problem. also, sometimes it idles rough, and sometimes when it's cold it stalls out when i put into gear but starts back up and runs fine. could they all be related?