Engine misses after sitting in storage all summer?

[KnappAttack]

Don’t overthink it. Like I said, rusty valves and seats. It will come back to life. They always do. If you take it apart you’d see how horrible it looks inside from sitting and all the corrosion and rust.

The Apex’s were notorious for being down on RPM after setting the summer due to rusty valves and old fuel, after running a tank of fuel thru the RPM always came back and it was fine.

I’ll never forget when we were running Wheelock’s first turbo open mod on the grass, Jeff Simon’s wanted to have a look inside the engine just to see how things were doing on an off race weekend, he took it apart everything looks so corroded and horrible inside, it looked like it had been at the bottom of the ocean! And it had only sat for one week in the trailer. It’s just what they do after they sit for a little bit. Maybe the lead lead race fuel makes this phenomenon worse I don’t know, but compression will be way down or even nonexistent because the valves rust. There’s just no way around it, but they always come back to life and make good power surprisingly after being run for sometime on the ground.


First start up they always run like crap and take a little bit to seat back up. Do not be alarmed.

 

[journeyman]

I always run a bottle of the Yamaha Engine Med RX at the beginning of the season, you’ll be amazed how much crud comes out of the exhaust too. A long time Yamaha mechanic I know swears by the stuff. You can find it on ebay.