Permatex MotoSeal 1 Ultimate Gasket Maker works well, but it's a bugger to use. Pretty much the same as Threebond 1104.

Threebond 1211 is what I use and it's good, but it takes a little time to cure. Another very good one is Threebond 1207B, but costs a small fortune. HRC use this.

Alternatively you could use raspberry jam. Doesn't work at all, but you get to lick it all off the motor as it squidges out.