Continuing with the exhaust...
Install the cooling line (water hose outlet) on the bottom of the lower pipe chamber. Also, check and make sure the brass elbow is pointed toward the outside of the ski.
Do both these steps before installing the lower chamber into the ski.
I pointed out during the motor removal to keep the hose from the donor ski which connected the exhaust pipe to the waterbox. Install that now to the lower exhaust chamber, its easier to do now than once its in the ski
Make sure the hose is long enough to reach where it will be installed to the pisser (see the orange line)
Use the collar/ bolt sleeves to help "hang" the pipe as you bolt it into place.