Re: 9.9/15 impeller housing tricks?

[johnyrude200]

All good info, but again, I need to get the motor back together before I can go further. I am going to run it without the thermostat first (which hopefully will show it running cold), then put a new thermostat in and retest. If all goes well, it should be OK at that point.

Dan I looked at the water flow diagram a few times before my initial post and they are very helpful. This is my first batch of 9.9/15’s I’m working on so there is a learning curve going on here, as I’m sure there will be more to come as I move onto other motors once I’m done with this style. Being able to pull the whole motor apart obviously is the best learning lesson.

Donny, I am in agreement with you between the two different bypasses; there is a thermostat bypass (on the thermostat, a small vent basically for water), and then some motors have a water bypass altogether (and from what I said before, it appears the 9.9/15’s do not have this). My point before is that the predecessors (9.5’s) had a water bypass, but if the thermostat was faulty the engine would still overheat with a stuck closed thermostat.

You’d see water pumping from the water outlet, but the motor would still overheat. It appears with these 9.9/15’s you’ll see the telltale but that doesn’t mean water circulation around the cylinders. It’s sort of a handy feature to help trace the issue – because at least you know water is flowing through the gearcase/water pump. If the stream becomes weak, that tells you ahead of time you have a gearcase originated water pump issue, or perhaps to your point, a grommet that is folded over or a leak somewhere previous to the tell tale.