Suzuki Outboard Thermostats

Suzuki Engine Thermostats - Resources & Information

PartsVu makes it simple to find the right Suzuki Outboard Thermostats for your Suzuki outboard engine. We offer same-day shipping on each in-stock OEM thermostat Suzuki produces for each model and year at the lowest prices you’ll find online.

In addition to offering a complete line of Suzuki Outboard Engine Thermostats, PartsVu is also proud to help boaters by providing helpful resources for Suzuki outboard motors:

• Suzuki Outboard Engine Oil Capacities & Oil Filter Chart
• Suzuki Outboard Engine Gear Lube Capacity Chart
• Suzuki Outboard 100-Hour Service Checklist
• Suzuki Outboard Season Breakout Guide

Suzuki Outboard Thermostats FAQ

How do I know if I have water in my Suzuki outboard engine block?

If you are confronted with water in your Suzuki outboard engine, the first place to look before disassembling the engine and checking for a porous Suzuki outboard engine block, cracked Suzuki cylinder head, eroded exhaust-water passage, frozen oil cooler, or other labor-intensive issues, is the Suzuki thermostat. Remember that some engines have two thermostats, like Suzuki’s V-engines.

To locate the Suzuki thermostat(s), be sure to refer to the service manual as the location varies by the engine. The service manual procedure states that you should put the thermostat in a pot of hot water and check if it opens and closes at the correct temperature. If you do not have access to this method, then an infrared temperature gun can be used at the Suzuki thermostat housing to get an indication of engine temperature. Again, refer to the service manual for the correct temperature operating range.

If you’ve determined that the engine is running cold, it’s a good indicator that the thermostat is stuck open. Remove the thermostat housing and inspect it. If it is stuck open, replace the thermostat with a new one, and be sure to do several oil and filter changes to ensure water is removed from the engine’s oil.

You might be wondering how water gets into the oil due to a thermostat being stuck open. If the engine is running cold, the hot oil meeting a cold engine can produce condensation. The condensation eventually condenses into water and falls into the oil. With an engine running cold, water isn’t the only pollutant getting into the oil. The piston rings (running cold) won’t fully expand to thoroughly seal against the Suzuki outboard cylinder wall and may allow a small percentage of raw fuel to constantly seep past them and collect in the sump. Prolonged running with this condition can cause the oil to develop a milky residue. Debris can also get stuck in thermostats and prevent them from retracting back to the closed position.

If you suspect water in the engine oil, there are a couple of quick ways to check. One way is to remove and look at the underside of the oil cap to see if there’s moisture in it. Another way is to pull out the dipstick to check for moisture in the oil. Either method is effective. Suzuki thermostat issues can be prevented by flushing the engine regularly per the owner’s manual.

How do I troubleshoot a Suzuki Outboard Motor?

It’s best to first address the simplest potential problems before getting into more complicated matters. The following quick fixes may address the reason your Suzuki outboard motor stopped working. 

• It may sound obvious, but check if there is gas in the tank. If so, is the tank vent open? A closed vent prevents air from replacing fuel as the motor pulls it out, which is necessary for firing up the engine. 
• If the kill switch isn’t properly attached it could very well be the source of your motor problems. Undo the electrical connection and put it right back into place. The kill switch may need to be replaced altogether. 
• The next point to check is your gear shift. It’s easy to knock out of place, which prevents the engine from starting. Make sure that you’re in neutral and try starting your engine once more. 
• Sometimes, the issue may simply be that your Suzuki engine propeller has something tangled around it. This may be a fishing line, excessive seaweed, or some other material that’s worked its way around the blades. Carefully remove anything that may be wrapped around the propeller, and give it a once-over for any damage that may be present. If the propeller is damaged, it needs to be replaced. Debris around the propeller is the most likely culprit if your boat motor starts, but quickly dies.
• Try to start the engine both with and without using the choke. If this doesn’t work, try altering the throttle position. Applying more or less gas can sometimes do the trick. Finally, squeeze the primer bulb a few times to make sure the engine is primed up.
• Some batteries have an on/off switch. If this is true for your battery, make sure the switch is on. Then, if your engine is under 25HP, you may be able to use the emergency cord to pull-start. It’s possible to do this with up to a 50HP engine, but be aware that the higher the HP, the more difficult this will be. If this works, the battery is likely the issue. You may need to replace it.

How do I perform a 100-hour service on my Suzuki outboard engine?

To ensure proper engine function, it’s always best to service your Suzuki outboard engine every 100 hours after the initial break-in period (first 10 hours) and after the first maintenance interval (at 20 hours). 

The following is a Suzuki outboard 100-hour service checklist to help you service your engine properly:

If you want a more in-depth explanation of how to perform a 100-hour service on a Suzuki outboard engine, read our blog “Suzuki Outboard 100-Hour Service Checklist”. Also, be sure to refer to your Suzuki Outboard Service Manual for which parts you’ll need, how to perform basic repairs, and other engine specific tasks

To make engine maintenance even easier, PartsVu has a wide selection of Suzuki outboard engine 100-hour service kits available. They’re pre-assembled with everything you need to keep your boat happy and healthy every 100 hours.

Why won’t my Suzuki outboard start?

If your Suzuki outboard doesn’t start, you’ll need to start from the most obvious causes, then move to more complicated possibilities. Here’s a run-down:

• Make sure that the kill cord is attached.
• Because your Suzuki outboard won’t start in gear, ensure the engine is in neutral.
• Inadequate fuel supply is a common issue, either from pinched hoses or a lack of fuel in the gas tank(s).
• Make sure that there’s no water in the fuel lines. Perform a visual inspection in the water separator bowl for traces of water.
• Look for fouled spark plugs (more common in small engines). If any fouled plugs are discovered, replace them with new spark plugs.
• Test your battery to ensure that it has adequate voltage. If it is underperforming or dead, consider replacing the battery and checking for any shorts that may be draining it.

For more info on troubleshooting your Suzuki outboard engine, be sure to read our blog “Suzuki Outboard Running Rough, Won’t Start, or Stopped Running” for a complete run-down of the most common issues you’ll face.

Why did my Suzuki outboard motor stop working?

Your Suzuki outboard ignition system is responsible for firing up the engine and keeping it running. Because checking this system may involve sparks and heat, keep flammable liquids away. 

The first part of the ignition system to check is the spark plugs. Clean and adjust the spark plugs– they may need to be replaced. Check the ignition spark with a spark gap tester. If you’ve got a good spark, make sure that the air gap is within specification. Adjust it if needed. 

If you have a good spark and the gap is within specification, the problem will likely not be found in the ignition system.

However, if you don’t have a good spark, salt buildup on the spark plug caps or ignition coil leads could be causing problems. You’ll also need to check both the spark plug caps and ignition coil leads for proper resistance. Replace degraded parts. When there is no salt buildup and both parts have proper resistance, check the ECM output peak voltage.

If your spark plugs don’t seem to be the issue, check that the electric oil pump and oil level sensor are in good condition. If so, check the reed valve for its condition.

How do I perform a leakdown test on my Suzuki outboard engine?

1. Step #1: Begin by carefully removing the top Suzuki cowling, Then, remove the ignition coil cover at the rear of the motor.
2. Step #2: Remove the spark plugs. Be sure to lay the spark plugs in numbered order to reinsert or replace them after the test.
3. Step #3: Remove the flywheel cover from the top of the motor.
4. Step #4: Mark the flywheel with a marker at 0°, 120°, and 240°. These positions will indicate where you’ll rotate each pair of cylinders to the top-dead-center positions (see Steps #11 and #12 below).
5. Step #5: Rotate the crankshaft with your ratchet and socket to the top dead center for Suzuki Suzuki cylinder #1.
6. Step #6: Adjust the regulator on the leak down tester to 0% to calibrate it for an accurate reading. 
7. Step #7: Connect the leak-down tester by screwing it into the spark plug port at cylinder #1. Next, connect the tester to the compressor and take a measurement. Be sure to firmly hold the crankshaft to prevent it from rotating.
8. Step #8: Rotate the crankshaft 360° (one full rotation) to put Suzuki cylinder #4 at the top dead center.
9. Step #9: Connect the leak-down tester to cylinder #4. Then, take a measurement while holding the crankshaft to prevent it from rotating.
10. Step #10: Set Suzuki cylinder #3 to the top dead center at the 120° mark. Next, repeat step #7 through Step #10 for Suzuki cylinders #3 and #6.
11. Step #11: Set cylinder #2 to the top dead center at the 240° mark. Then, repeat step #7 through Step #10 for Suzuki cylinders #2 and #5.

Step #12: Replacement is the same as disassembly. Be sure to replace spark plugs in numbered order and apply an anti-seizing lubricant on the threads for easy removal/replacement in the future. Also, firmly reattach the ignition wires for a solid connection.