gray stuff leaking out of tri-z motor??

[Red Rider]

Use a gasket. You should be able to get one from Yamaha or an aftermarket gasket company like Vesrah.

[Yamahauler]

I don't recomend Versah, get OEM. I had Versah and they leak like crazy. Some other people have also had troubles with their gaskets.

[TimSr]

There is no way coolant can get into your bottom end through the base gasket, or the head gasket for that matter. The base gasket is a vacuum seal, with no coolant running through it, and will mostly suck air if it leaks, with some pressure on the downstroke. If the head gasket leaks, coolant can go into the cylinder, mostly out the exhaust with huge amounst of steam, and possibly accumulate in the crank, but it cannot get into the gearbox from there. Usually a leaking head gasket causes problems in teh other direction, with cylinder pressure, pressurizing the cooling system and blowing coolant out the overflow.

Read Derricks post. My guess is youll probably also find that the impeller has separated from the shaft and needs replaced as well as the seal.