Re: 4.3gl SX Overheating
some sugestion:
If you have raw water cooling system:
1. check belt tension (raw wateer pump and engine circulating pump will be affected by loose belts)
2. check raw water intake at the stern drive (clogged, obstruction, mesh dirty, loose hose, etyc.) would prevent water intake toward the reaw water pump.
3.raw water pump failing to prime due to air (ck hoses clamp, as loose hosed will suck in air creating turbulence and preventing priming as well as reduced water flow through then pumps, resulting in poor cooling of the engine and manifolds)
4. perfom raw water test (while boat is in the water or attaching test mufflers with water connection at intake) loose raw water discharge hose start engine and observe if water is circulatin, approx. 2" hnigh if holdiong hose up, if no water, your raw water pump has no suction; if work, turn engfine off, reconnecto hose and disconnect the 1.5 hose at the thermostat assembly, star again the engione and observe water circulation, if no water, thermostat is not opening (will open when egine reach over 160 F)
do not RUN engine over 15000 RPMs while doing these test and keep hand off the engine belts. each test should not take more than 10 second while engine is running. If using the water hose connection to the intake, make sure that water reaches all the upper hoses by disconnecting them and looking for water circulation.
In addition, you may need into the tune up, engine timimg and sensors at the endgine and the manifold to make sjure that they are working properly; it helps to have a laser thermomether or other kind to double check engine temperature and n ot relying on the dash board gauges.
