How Cool(ant)

“The heat is ON!” ~Glenn Frey

It is that time of year again in the southern stretches of Florida…the dog days of summer.  But this far south, that dog is a Great Dane.  Oppressive heat and humidity have taken hold.  Opening the door from my air conditioned house is akin to walking into a dryer full of wet towels.  It feels like you could lay a surfboard on the air and float away…and it is HOT.  Average daily temps soar into the 90’s, with heat indices easily reaching triple digits due to humidity hovering in the 80 – 90% range constantly.  Heck even overnight, our “low” temperature sinks to a toasty 82 degrees.

All this extreme weather pushes engines to their limits.  Engines run hot, and when you factor in the heat outside, they run even hotter.  It is paramount that engine cooling systems are properly maintained and running fresh fluids to ensure safe, reliable performance.   Yamaha and Kawasaki PWC are raw water cooled…meaning that they extract sea or lake water and cycle it directly through their cooling loops.  This is a good system…tried and true.  There is no shortage of water where you are riding.  If you run in freshwater lakes and rivers, it is ideal.  However if you run in salt water, a new concern emerges related to corrosive salt deposits being left behind inside your engine.  Products like Salt-Away were developed to combat this problem.  It is a simple system that involves hooking up a small reservoir (for holding the Salt-Away fluid) to your garden hose.  When you run the hose to flush your engine, the Salt-Away is diluted into the hose flow and run through your engine, and the salt is purged away.

But then…there is Seadoo.  I have one, and I love it to pieces.  One of the things that make them different from the other brands is their engine cooling system.  All 4-stroke Seadoos have closed loop cooling systems.  They do not run raw water for engine cooling (only for exhaust cooling).  They have coolant, just like a car!  Gone are the days of cycling rot-inducing seawater through the cooling system!  Great…right?  Well, yes and no.  Yes, of course it is wonderful to run nice clean antifreeze/coolant through the engine.  It definitely goes a long way to maximizing engine longevity.  But with this technology comes an additional set of maintenance not required in Seadoo’s open loop comrades.  Coolant is a fluid that has a lifespan, and therefore it needs to periodically be drained, flushed, and replaced.

In light of a recent problem I had with an engine overheat (related to oil that had gotten into my coolant after an oil cooler failure), I changed out my coolant.  And decided it would be great fun to share the experience with y’all!  For those of you with other brands that are scoffing or yawning or relieved that you have open loop systems, thanks for tuning in!  The remainder of my diatribe will be devoted to the (surprisingly simple) procedure of changing coolant in a Seadoo.

Allen head bolt drain plug.

Draining the old coolant is very easy!  On the back of the ride plate, dead center, is a small allen head bolt.  That is the “cork”.  Before you unscrew it, I recommend laying down some old cardboard or plastic, and get yourself a 5 gallon bucket, and then a smaller second bucket (a spackle bucket works great) and have them handy.  Place the 5 gallon bucket beneath the rear of the ski.  Unscrewing the retainer bolt is much like doing the same to change oil on a car…when you start to get near the end of the unthreading, the fluid will start spouting.  The coolant is under pressure, so it will not just dribble straight down…it will shoot outwards like a supersoaker!  So you may want to get ready to hold the bucket up at a 45 degree angle as soon as the bolt is out to catch the Niagara Falls of ectoplasm!  Note:  I like to first drain coolant with the pressure cap still screwed ON the coolant reservoir bottle.  After the first gush slows down, I then unscrew the cap and get Round 2.  I find it to be a more controlled way of dealing with the pressurized fluid draining.

MiniMe bucket

Once the coolant has stopped gushing like a fire hydrant that got backed over by a garbage truck, swap the big bucket for the smaller one.  In order to really drain the old stuff out, you need to be able to tip the ski back.  The big bucket doesn’t really leave enough clearance to do that.  Lining up the smaller one in just the right spot takes some practice (hence the plastic/cardboard underfoot!).  Then it’s tippy-tippy.  I wedged a piece of scrap wood under the main crossbeam of the trailer and left it tipped for an hour or so while I did other stuff, but I would give it at least 10 minutes to let gravity work its magic.

Next it’s time to refill.  This is done simply through the overflow reservoir bottle situated in the rear of the engine compartment.  You will need a funnel!  And a fresh clean bucket.  With the drain plug OPEN and the clean bucket in place, begin pouring fresh coolant (I use 50/50 coolant/antifreeze) into the reservoir.  As it begins to percolate through the system, it will eventually make its way out through the drain plug.  You will want to leave the drain plug out until the stream of coolant exiting is steady, and not spouting with gaps.  This indicates that all the air has been purged from the lines.  Replace the plug bolt.

Gross...my coolant bottle has turned an ugly shade of orange

Then continue pouring coolant into the bottle until it reaches the ‘FULL/MAX’ line on the bottle, and replace the cap.  Remember that you can use the coolant that is sitting in your clean bucket…that is why we changed buckets!  You could either pour it right into the reservoir after screwing in the drain plug, or pour it back into the jug.  

Now comes the fun part!  In order to make sure that the coolant gets properly and fully circulated throughout the system, the engine must be brought up to operating temperature so that the thermostat will open up and flow the coolant.  I DO NOT recommend attempting this on dry land with the garden hose…it realistically takes a good 10 – 15 minutes of idling to get to that point, and you run the risk of overheating your exhaust running it that long on the trailer.  So either back it down the ramp and run it with the exhaust in the water, or…get out and go for a ride!  Take it easy for the first 10 minutes…just idle around near the dock, and then stop, wait 10 minutes for it to cool, and then check fluid level.  Your ski should have drawn some of the coolant from the reservoir into the system.  Top off, but this time just to the middle line.  Then go back out and ride around for another 10 – 15 minutes, but get on it a little more.  Get up on plane (but still not WOT).  Come back to the dock and check the level again, and top off if necessary (waiting until the ski has cooled a bit…if you open the cap while the ski is hot, the depressurization will spray you with hot coolant!).  That’s it!  You are good to go.  I make a habit of checking the coolant level once or twice more…I am paranoid!  But paranoia can sometimes save you!

At this point you are probably either thanking your lucky stars that you do not have a Seadoo, or thinking that a ski running coolant is a good innovation, and now that you are equipped with the knowledge of how to change it, realizing that the little bit of effort every season or two is worth the benefits tenfold.  That’s up to you!  Personally, I love it.  For the occasional bit of extra maintenance, the benefits of not running salt water through my engine are enormous.  I only ride in salt water, so it is a worthwhile feature for me.  Maybe for owners of open loop systems, running Salt-Away after every ride isn’t a big deal.  But I am willing to bet that 80%+ of people running open loop systems do not…buyer beware with used skis!

I am at least feeling better about running my beloved ski around in the heat of summer, knowing it has fresh, effective coolant in it.  Considering that surface water temperatures here in the Keys are in the mid 80’s, you need to give your PWC every advantage to help it run as cool as possible.  Be good to your PWC this summer, and it will be good to you.  Maintenance is key to longevity and reliability…no one wants to go back to the dock on the end of a tow rope!  Stay cool(ant)!