'05 Supra 21v Vapor Locking Update

Thanks again for all the help. Here is an update. We took our boat out again this Saturday and rode all day and kept the blower on and hatch opened every time we stopped. The boat did fine until we stopped for about an hour to swim and relax. When we fired the boat up, same problems! The boat vapor locked and would not crank. Armed with my new knowledge, I dipped a towel into the lake and put it over top the fuel pump. We set for about five minutes and tried again. Boat fired up no problem! Thank you Wakeworld! That night I was reading through the service manual and noticed that the thermostat is a 160. My boats temperature reads 180. I replaced the thermostat thinking it might be stuck or malfunctioning. Put the boat back on the lake Sunday and the temperature gauge goes past 180 and then settles at 180 when the thermostat kicks in. Should my boat be running at 160 with a 160 thermostat? What is normal operating temperature for Indmar 325? Would this cause the Vapor Lock problems?

i had a 05 ssv 22 with the same engine. never had any vapor lock issues, but the engine temp was always at 180 degrees.

both of my other inboards with indmar have always been at 160

I guess my question is why would a 160 thermostat not kick in until 180 and then hold temperature at 180?

That's a good question...I know with my boat the the gauges are off a bit. Was worried about my charging system the past two years as my gauge reads 13V and PP reads 12.6...but I checked the batts (when motor is off) and they both have a full charge and the buss bar under the helm reads 14.4 when at idle. BTW my temp runs ~160-170. Reads upto 180 for a minute when switching riders.

Robert, I have an 05 22ssv and my temp reads 180 or just a little above as well. I haven't had any vapor locking issues yet....keep my fingers crossed after reading your issues with that.

I am still running the same tank of gas so don't get too paranoid. We were told by Indmar that winter blend fuel sounds like a good cause. I plan on running this tank dry before refueling and hopefully the problem will disappear. I was just wondering why a motor would run at 180 with a 160 thermostat?

Robert, Its time to check your transmission fluid cooler for blockage on the water side. Its pretty easy, here's how. From the water intake in the hull, follow the hose to a black painted shell and tube heat exchanger mounted just below the spark plugs on the passanger side of the boat. Remove bottom hose from the heat exchanger and inspect with a flash light and a hand held mirror. You should see about 30 little copper tubes that the water should pass thru. Remove any blockages GENTLY your fingers. This should take about 15 min. If 1/2 are plugged you are only getting 1/2 flow for cooling and will start raising tempature. If this becomes a common occurance ask your dealer to get you a strainer to make cleaning much easier.

I will do that for sure. Thanks for your input! Your trick with the water and fuel pump saved us from another tow this weekend!

Just got through checking the transmission fluid cooler and it only had a couple of pine needles stuck. I haven't put the boat back on the water yet, but there was not enough (in my epinion) to block water flow. Any other suggestions?

I would check the impeller on your water pump just to be safe. If it looks ok button it back up and go ride.

Indmar's right most vapor lock problems are caused by winter blend gas.

I am by no means a mechanic, but I do have an opinion on running on gas that's been in your tank all winter. In the past I used to fill the tank full and add Stab-bil when storing my boat during the winter months. When spring came around I would crank up the boat and it would run like crap until I got through the old tank of gas.
I read a post a few years ago about a home done study about condensation in the fuel tank during winter lay up. Long story short, the conclusion of the study was that the amount of condensation is very minimal and that running your boat on old gas may actually be worse.

Since reading that post a few years ago I have been storing my boat during the winter with about a half tank and a 20 gallon treatment of Stab-bil. When taking my boat out again after winter lay up I fill the tank full, thus having 1/2 a tank of old gas and 1/2 a tank of new. The difference in performance was drastic. No longer was my boat sputtering on old gas.

I've been doing it this way ever since and have had zero issues. This may or may not be the solution to your issue, but it may help for future lay ups.

I am not using the same gas from last season. We have put at least 3 tanks (not sure of exact number) of gas in this spring. We have put over 30 hours on the boat since we bought it in December. Up until about a month ago, the trips to the lake have been short and sweet because of the chill in the air. Now that the weather has flopped, we are spending all day on the water. I plan on running the tank as close to empty as possible and then pumping the remaining out and start with a clean slate. I have roughly a half of a tank leftover and should be able to run that out by the end of the week. If I am still having problems, then I can start disagreeing with Indmar and the Dealers. Hopefully Summer-Blend gas will do the trick.