Motorcycle Repair: 85 honda nighthawk, honda nighthawk, water intrusion

Question

Chris, its been a minute...

I have been tinkering with the engine with little success tuning the idle speed.  Carbs were rebuilt and the plugs are getting a fat white arc.  The Choke cable is un reliable but I Have a replacement. Interesting thing though,  I started to do an oil change and the oil came out a creamy "Bailey's" color.  Figured that there may have been water in there.  In fact sabotage was suspected because The original gas tank was full of water and rusted in such a way that probably wouldn't come from one year exposed to whether.  The amount of water seem excessive in the oil.  I wonder what kind of damage could occur from trying to start the bike in this condition.  At time the engine has run but erratically requiring almost full throttle to keep from stalling.  After draining the oil pan and the filter housing I have been adding a few quarts and allowing it to drain right through.  Figured I would close the drain, top up the oil and try to start it to circulate it a little a ......

In addition, I am wondering if the carb floats are allowing fuel to flood the engine.  It they are, can it be gas mixing with the oil and not water.  Since tinkering with the adjustments on the carbs, I hear what sounds like gushing fluid in the engine and the plugs seem to have gone from a glazed coat to a moist feel where the glazing just rubs off. I'm still thinking of pulling the carbs and starting to over with the rebuild.  Starting to wonder if the engine may need an overhaul.

Mike


Answer
Hi Mike.

I would suspect sabotage as well in this case.

Flushing the old, water saturated, oil out of the bike is definitely called for.  An overhaul can't hurt, since there is no way to tell how badly the water intrusion really is.

If you don't do the overhaul, then get about 12qts of the correct oil and 3 filters and do the oil and filter change.
 Run the bike for about a few miles (3-5 at casual speeds), then change the oil and filter.  Do it all again and change the oil and filter again.  It should be cleared sufficiently by then.

 That white stuff is actually a fungus that grows in petrolium products (mostly oil) when there has been long term water intrusion in the oil.  It grows from bacteria in the water and sticks to the oil.

Get the carbs cleaned and rebuilt professionally.  They may need more work and precise adjustment than your own humble efforts may be able to muster.  In lieu of that, you could just replace them with new ones.

Good luck and ride safe.
FALCON