dirt in manifold

[Doug M]

I ran through some shallow water and sucked up some mud. I pulled my thermostats and cleaned them but I can still see some mud caked in the manifold. is there a way to flush the manifold? do I just hose out from the thermostat hole? do I run it without thermostat briefly? Thanks

 

[joereeves]

I've done that more than once..... Usually it blows out with no problem all by itself, however, when in doubt... remove the thermostats temporarily and give it a run for 20 or 30 minutes at various rpms, then replace the thermostats as they're there to have the distortion of the cylinder sleeves and the pistons to coincide with each other and as such.... constant running without them regularly will lead to scored pistons and cylinder walls.

Some boaters in my day who have eliminated the thermostats to eliminate a overheating of the engine have unfortunately discovered that damaging effect of "No Thermos".