Tach and low rpms issue

[red devil]

I noticed that when i first start my motor for the first 10 seconds or so when I trim motor down the tach quits. After it's been running for 15-20 seconds it's fine. It's also only running 5400-5500rpms. The only thing differnt is I switched gas tanks.I thought it was bad gas in that tank,but I siphoned all the gas and put fresh premium gas in and the rpms didn't come back. It went from 6100 rpms down to 5400. I also put new plugs in. I don't know if it matters but this is a 3.0l limited edition.

[red devil]

Oh the speed is down also. I was running upper 60's now it struggles to hit 60.

[red devil]

[CFISH31]

I have the same problem since I winterized mine last year as well an answer could help a couple of us..