Re: Flushing 15 HP Honda
Jerry,
Is the flush port located at lower leg or on cranckase ? Unless you have a out of this world house water pressure will need to seal lower water intakes to achieve best flushing pressure inside engine. An engine that doesn't have a thermostat doesn't need to be flushed with engine on. but a 15 sure has one.
Answering your questions:
1-Don't have a clue for that one, My ex Evi 15 owners manual recommends flushing with engine on or offf, off doesn't clean a bit head and thermo water passages, engine on does quite well.
2-Water finds its way inside cranckase water paths and head if thermo is open, then goes down the exaust to lower unit and out through prop.
3-Is for engine to drop dead with carb bowl dry. OTOH removing fuel hose from engine will give a shorter flushing time period than not doing so. Can flush all you want with hose on.
4-Should be flushed after its daily use, see it this way: If you don't flush it after each day use microscopic salt layers will inevitably be formed inside all coolong water passages, if continuing with this, will have in a long run excesively salt layers and even salt crusts throughout the whole cooling system.
Would be a real crime to do this on a brand new engine. If all water paths remains in near immaculate clean cond, internal engine heat will dissipate faster and engine cool much better than an engine that's already severely salted. If engine will ran on a daily basis and then be removed from boat, flush it.
Sometines the practice is contraty to the owners manual written theory.
Happy Boating