Psycho Heater and Stubborn Outboard

Almost sounds like a couple super villains that Superman should be dealing with, but in fact are a couple things we did battle with today.  The day started with me finishing the wax of the hardtop (a task we put off so we could escape Virginia). When I came back inside, I noticed the heater was acting a bit strange. Just as I came in, the air conditioner kicked on (one of the nice perks of this marina...electricity is included). I glanced down and noticed the thermostat said it was 83 degrees. Then it said 84, 85, 86, 87, and 88 as if it were practicing counting with Big Bird from Sesame Street. I guess it was happy with 88 so then it started counting backwards until it reached 75 and the AC unit shut down (the thermostat was set at 76).  A couple minutes later the unit fired back up and I looked over and it was claiming 82 this time.  The whole time I doubt it was over 75 inside.

The thermostat has been acting a bit flaky lately, but this is by far the wildest swing we had noted.  I checked the temperature at the thermal sensor at the base of the thermostat and the non-contact thermometer claimed it was 72 (and I know it reads 2 degrees low).  I turn the unit off, wait a few minutes, and turn it back on. It claims 83 again and this time it just stays at 83 for a while. I start thinking that the thermostat is going bad and do a little research on the cost of a replacement on the internet while it starts practicing counting forward and backward between 75 and 90. Big Bird would be proud.

The psychotic air conditioning
controller

The thermostat/controller I come to find runs about $200 online.  Ouch.  I decide to try unplugging the controller wire and plugging it back in.  No change.  I decide it is time to clean the filter and unit anyway (it is amazing how fast dog hair collects there when you have two aboard) and just take a look at the whole unit even though I doubt it will change anything.  I get the shop vac out and vacuum up the dog hair and then clean and rinse the reusable filter.  For no real reason I decide to look at the control circuit panel.  I open up the box and don't notice any burnt trace wires.  I decide to unplug the control wire and plug it back in again. I put every thing back together and turn the unit back on.

To my utter surprise, the thermostat reads 75 degrees.  Huh.  I change the temperature setting to 73.  The unit turns on and blows cold air and the thermostat slowly goes down to 72 and then the unit turns off.  It continues acting perfectly normal through another cycle.  I change the temperature to 75 and continue to monitor it for the rest of the day.  It seems to be acting perfectly normal now.  Cool! (no pum intended)  My best guess is that, contrary to what one might think, the controller doesn't read the temperature and just tell the unit when to turn on and off, but the controller board on the air conditioning unit does this.  The act of re-seating the plug on the controller probably knocked some corrosion off and now everything works. Keeping my fingers crossed that it stays that way.

The other task was one I had planned for today.  I've continued having some issues with getting my dinghy motor to idle well.  A while back in Brunswick I even had a shop work on it and it seemed good for a short while, but soon it would be back to dying when at idle.  A couple days ago I hooked up a garden hose to an outboard fresh water flushing adapter so I could run the engine while mounted on the rail of the boat (this supplies cooling water to the motor when it is not sitting in the water).  I fired the thing up and played with it for a little bit. It would run for a while, then suddenly sputter and die.  I'd start it back up and it would run for a while, then suddenly sputter and die.  The engine seems to run fine when not at low speed.

Stock photo of the
model from Yamaha

One thing I did notice is that when the motor sputters, it tends to smoke a lot. Since I didn't have any history on the motor (it came with the boat) and it looked pretty new inside, I wasn't sure if the break-in was complete. So, to be safe, I did add more oil to the gasoline (this is a 2-stroke) than is normal. I don't know if this is contributing to the issue or not, but I will likely return to a normal mix next fill up.  In the meantime, I decided to try readjusting the idle mixture. With the engine off, I gently tightened the idle mixture screw until it bottomed out, recording the number of turns (so I knew were it was set and could reset it there if needed).  I then turned the screw out to where it was and then just a little bit more so it would be set a little rich.  I started the motor and let it run a bit and it idled OK at that setting.  I then slowly tightened (closed) the idle screw, allowing the engine to stabilize about each 1/4 of a turn. Once it started stumbling, I turned it back 1/4 turn until it was idling OK again. I let it run for a bit and it seemed happy.

This was all done with the engine mounted on the rail, so all that was left was to take the dingy for a spin and see if it would run OK.  While this was work, it was also fun. We dropped the dinghy into the water and mounted the motor on it.  We started off with a low speed cruise around the marina (so I was never all that far from the boat or the tools).  The motor shifted into and out of gear at idle speed, didn't stall, and seemed generally happy. Next I dropped my wife back off at the boat (so I would have someone to call in case I got stranded somewhere and needed a ride back) and took it out on the ICW for some higher speed runs.

I started with a couple of short high speed runs (not beyond what I was willing to row back from) and everything seemed good to go. When the engine was brought back to idle, it would continue to run just fine. I increased the length of the runs as I gained confidence in the operation.  My longest run was about a mile and the whole time the engine performed well.  When I got back to the marina, I found some dolphins jumping and playing in the basin, so (after watching them a bit) I decided to let them be and did a little more touring of the area with the dinghy.  Man this boat can fly with a single person on board.  That 15 hp motor brings the RIB up on plane and zips right along.  I turned into one of the canals and looked at some of the homes that have easy access to the ICW.

I eventually made my way back to the boat, and the outboard ran perfectly the whole time.  We pulled the motor off the dinghy, placed it back on the rail, and put the boat back on the davits.  I then hooked up the hose and did a fresh water flush of the motor.  In order to clean the salt water out of the cooling passages and drain the carburetor at the same time, I do this run of the engine without the gas tank connected.  The engine can run for a couple of minutes (depending on how fast you run it) without the gas tank attached by draining the gas sitting in the carburetor bowl.  I've found this is just about the right amount of gas to give the cooling system a good flush.

We are getting things ticked off the list in preparation to leave the marina and spend a bit more time on the hook. With any luck, we will be continuing our journey soon.