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1986 Yamaha 90 ETLK cooling flow problem
I recently picked up a 1987 Yamaha 90 ETLK. When testing on the trailer, and on ear muffs, I don't get water from the tell tale and the engine quickly gets hot. Apparently the previous owner was neglectful with proper flushing.
The engine has a brand new head with poppet, thermostat, and water pump. Before cranking the engine for the first time, I inspected it thoroughly and performed a compression check revealing 125-PSI on all three [cylinders] when the engine is stone cold. All looks good, it starts easily and runs smoothly.
I noticed no water out from the tell tale and started investigating. With ear muffs, it never pushed water up and out of the tell tale. I pulled the thermo cover and found a small amount of salt crustiness. I cleaned that out and reinstalled them but no water ever came from the tell tale when running at any RPM.
I removed the thermostat cover again and ran the engine with it off. Water pushed out the top with the foot in a barrel of water and no water hose pressure. Assuming I did not get the pump primed at first, I reassembled the thermostat section and cranked it again. No water.
Assuming there were blockages in other areas, I did the salt-away process by pouring it thru the thermostat hole, letting it soak for 20 mins and then running the engine briefly to push any debris out the top. The cleaning solution flowed out through the foot and did not seem to find any restrictions. While apart, I tested the thermostat in a pot on the stove. It started opening at approximately 160-degrees. The thermostat is shiny brass and appears to be new. The poppet valve and O-ring appear new too.
I reassembled again and no luck. With the thermostat installed I get no flow out the tell tale and the engine quickly gets hot. I don't let [the engine heat rise to the level that would sound an] alarm. I just use a laser thermometer and read the heads near the plugs, and I shut off the engine if the readings on the thermometer approached 180-degrees externally. With the thermostat OUT, the temperatures all over the head and exhaust plate on the side are very cool, never reaching 100-degrees. I assume inside temperatures are getting hot, but not reaching dangerous levels. Also, water ALWAYS flows out the front water return hole on the foot regardless of whether thermostat is in in or out.
Any ideas why I see no tell tale water and it gets hot quickly? Why no flow with the thermostat installed and plenty of flow with it removed but the cover is installed? If the thermostat is normally closed, I should still have tell tale water flowing, right? Any help will be most appreciated!
The engine has a brand new head with poppet, thermostat, and water pump. Before cranking the engine for the first time, I inspected it thoroughly and performed a compression check revealing 125-PSI on all three [cylinders] when the engine is stone cold. All looks good, it starts easily and runs smoothly.
I noticed no water out from the tell tale and started investigating. With ear muffs, it never pushed water up and out of the tell tale. I pulled the thermo cover and found a small amount of salt crustiness. I cleaned that out and reinstalled them but no water ever came from the tell tale when running at any RPM.
I removed the thermostat cover again and ran the engine with it off. Water pushed out the top with the foot in a barrel of water and no water hose pressure. Assuming I did not get the pump primed at first, I reassembled the thermostat section and cranked it again. No water.
Assuming there were blockages in other areas, I did the salt-away process by pouring it thru the thermostat hole, letting it soak for 20 mins and then running the engine briefly to push any debris out the top. The cleaning solution flowed out through the foot and did not seem to find any restrictions. While apart, I tested the thermostat in a pot on the stove. It started opening at approximately 160-degrees. The thermostat is shiny brass and appears to be new. The poppet valve and O-ring appear new too.
I reassembled again and no luck. With the thermostat installed I get no flow out the tell tale and the engine quickly gets hot. I don't let [the engine heat rise to the level that would sound an] alarm. I just use a laser thermometer and read the heads near the plugs, and I shut off the engine if the readings on the thermometer approached 180-degrees externally. With the thermostat OUT, the temperatures all over the head and exhaust plate on the side are very cool, never reaching 100-degrees. I assume inside temperatures are getting hot, but not reaching dangerous levels. Also, water ALWAYS flows out the front water return hole on the foot regardless of whether thermostat is in in or out.
Any ideas why I see no tell tale water and it gets hot quickly? Why no flow with the thermostat installed and plenty of flow with it removed but the cover is installed? If the thermostat is normally closed, I should still have tell tale water flowing, right? Any help will be most appreciated!
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