Attempt at fixing my hot start issue on my 08 15F

[gixxer1kr]

Been dealing with the intermittent hot start issues when the water Temps are warm and I shut the ski off for a little while. Only way to get it to fire up is to wait or pour cool water on the water temp sensor. Gonna give this a shot. Should get hot enough running to do its job and hopefully dissipate the heat better when the motor shuts off.

[grumpy_steven]

Easy answer is to let your motor idle for 30 seconds before shutting down. If you run at WOT, then shut down the motor before the cooling system does its job, you get the heat buildup.

[gixxer1kr]

Easy answer is to let your motor idle for 30 seconds before shutting down. If you run at WOT, then shut down the motor before the cooling system does its job, you get the heat buildup.

I've tried everything. Nothing's works. The exhaust manifold is too hot and it heat soaks the temp sensor and won't start. My buddies 2 Stx 15s never do it. Might be the R&D kit. Does have exhaust work.

[grumpy_steven]

If your exhaust manifold is getting too hot, you should be looking for a cooling system blockage.

Pull the two hoses off the end of the waterbox and clean out the fittings.

[gixxer1kr]

Grumpy is there anywhere I can read how this whole cooling system works. This is my 1st ski. Used to land vehicles lol..and which hoses should I be checking. The guy before did some performance work and cut out the 2ndary water box and added a water pisser on the back.

[sirbreaksalot]

its not a cooling issue..............its an ECU calibration issue.

Waz

[gixxer1kr]

Yeah that's what I thought Sirbreaksalot. Some skis do it some don't.Also read about updated sensors and a ecu reflash. Some also wired in resistors to bring the readings down a tad .

[sirbreaksalot]

12f & 15f & lx do it.... as you said not all and not all the year round .....there seems to be a certain temp window were the Ski just wont start,
I have made up a timer switching relay that switchs to a set MID SCALE TEMP VALUE via a resistor on the ECU input side reading only on start cycle, then the relay holds that position for 5 seconds then drops back to the engine sensor............. basically allows the water to hit the sensor , which brings it back to scale and runs just fine.......have been thinking about making a potted version to sell

[smokeysevin]

The issue at hand is that the sensor is calibrated to read correctly when the engine is running and full of water, when you stop the motor the water drains out of the waterjacket and then the sensor gets heatsoaked by the now dry exhaust manifold.

I like that idea Waz,

Sean