200 Mercury 15 hp 4 stroke outboard (15ML 4ST): tell tail issue

[tuan]

Tell Tail issue: I bought this used, and have replaced oil filter, oil, spark plugs, gear oil, impeller. Engine starts fine but notice that tell tail does not pee, only exhaust fume comes out (hot air). When engine is idling, water comes out between port cover (starboard) & adapter (slightly above lower unit & gear housing)
Things I have done and validated:
- impeller is properly installed with pin in correct position.
- coupler from water pump to engine water tube is correctly connected.
- hose between engine & tell tail is clear of clogs
- blow water backward from tell tail into engine and water comes out at bottom section (slightly above the lower unit).
Manual says that engine has to be warmed up before the tell tail appears, but I am afraid of running engine too hot (I did let it idled for couple minutes max, and no pee).
I also temporarily removed the thermostat: and still no pee.
My plans:
- Remove the thermostat cap, and let engine run to see if water comes out from there.
- Blow water backward from tell tail with thermostat cap remove and see if water comes out from thermostat.

If anyone has any other ideas, please help.

Thanks
Tuan

 

[dnmn100]

what year is this motor? I am having same issue with my 2017 15hp

 

[km1125]

I think you should always have the tell-tale, whether the engine is warm or not. If the engine is not warm, the cooling water just bypasses the thermostat. Most telltales (I think) are before the engine which tells you that there's pressurized water getting TO the engine.

Are you sure your impeller has the right "set"? This is which way the vanes are facing. I think they will flip around once it starts spinning but I wonder if some don't.