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Tohatsu MFS30B with water blockage

M

Macca27

New member
I have a 2008 Tohatsu MFS30B 30hp 4-stroke that has no water coming from the check port but the pump is OK and intact. The over heat indicator also comes on so its not just a blocked indicator tube. The motor has had very little use as it was an aux motor and hasn't been run for 12months. Water pumps out of the flushing attachment hole with the plug removed and this is where my knowledge about this motor finishes. I was hoping that someone might have a few suggestions .Thanks in advance
 
If your motor is a Long shaft, you may have had the water tube collapsed by freezing. What is your serial number?
 
It's a long shaft and serial No is 064769XH. The water tube is OK as water exits the flushing attachment hole under good pressure.
 
If you have great flow at the flushing attachment port in the block, the water tube should be OK. You may have a blockage (some debris in the cooling system) and/or a stuck thermostat. It's possible to have both problems at the same time. I have seen sand, mud, and crud in cooling passages in the base plate and block on the MFS25/30B if the motor was accidentally grounded in a muddy harbor. If you have access to compressed air, you can blow into the telltale check port while the motor is running (or while supplying water to the flushing port)... if there is a bit of debris, you may be able to clear it. The thermostat can be checked by putting it into a pan of water with a thermometer and heating it to about 140-160F. It should be fully opened by 160F.
 
Thanks for your help Paul. I just discovered that the telltale check hose comes from the block via a fuel cooler that I found to be blocked. I disconnected the tubes and dislodged and blew out the offending crud which should clear that problem as I can now blow air freely up the telltale and it exits the flushing attachment port. I haven't run the motor as the bottom section is off at the moment but I'm still wondering why the alarm buzzer went off if it was only the telltale that was blocked. I'll try it again on the weekend tackle the thermostat if it happens again. Thanks again
 
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