Re: How to know if the engine is running at the right RPM's, Heat range, etc...
The only way to know the engine RPMs is to install a Tachometer. <br /><br />For engine temp, look for the tell-tale water peeing out of the right side of the engine. If it is not pumping out strong (may take a few seconds after startup) at idle, you probably need to replace the waterpump. Typically, these should be replaced every 2 years. They are easy to replace yourself. If you don't see a good stream of water, don't run the engine at higher rpms until you fix it. The water stream should have enough pressure to shoot straight out from the little nozzle. <br /><br />Also, change the lower unit gear oil. It is easy to do. Put a container under the lower unit. Remove the lower drain screw (on the left side of the lower unit). Remove the upper vent screw. The fluid should run out. If it is grey and sludgy, it has water in it. A common source of water intrusion is the seals on the lower unit fill and vent screws . These seals seem to magically disappear at times. They are cheap to replace. To refill, buy new lower unit gear lube (Napa, Walmart, or marine dealer) and squirt it in from the drain hole. When you see the fluid at the top vent hole, continue to hold the gear lube tube in the bottom hole and screw in the vent screw. Remove the gear lube tube and then replace the screw in the drain screw.
