riser questions

[bruce stamford]

has anyone ever had a riser get hot, and also get steam out of the exhaust. Here is what has been done. new water impeller, thermostat, risers manifold(mercruiser) motor temp stays at 150 and motor runs great, plugs are looking good. #1 exhaust port looks good same with 7 but some crystals in #3 and 5? cool on idol and low rpm. riser gets hot under a load? no white in oil and level is good..

 

[GandDFreehold]

I had the exact same problem a few years ago.Tried everything you did, all to no avail. The problem ended up being the tube coming from the water pickup, in the drive, through the gimbal housing. At idle everything was fine, under load the hose would collapse, restricting water flow, to the raw water pump.
Hope this helps.