blevis213,
I've never had a 4 stroke Yamaha with rear exiting exhaust NOT spit a little gray sooty water out during warm up, usually just some evidence on the tunnel extension and grab bar or around the rear plastics when stock but not like that...
Two things...
First it takes exhaust outlet velocity to sling it out all over that far like you described, which is a result of that silencer... My turbo Apex slings it pretty good, enough that I stand a piece of cardboard up behind it when i start it up in the shop so it doesn't lightly spritz everything behind it, but it also only has a small muffler after the turbo so the exhaust velocity is pretty fast too. It also idles at 1800 RPM and makes LOT of condensation during warm up.
Second there has to be a pretty good existing amount of soot buildup in the exhaust to wash out with the condensation like that too, and that doesn't just happen during warm up. It's a result of the sled running too rich ALL the time, which is a result of your add-on fuel controller programming (and that doesn't take much to also directly influence fuel mileage). Again my turbo Apex makes a lot of soot too because the AFR is rich most of the time due to the high boost levels it runs.
So you have a combo of things making it into a "slinger", but rest assured it's not a mechanical issue with the engine.
