kelzamedic
New member
Running a 2003 Mercury carbureted 200XL, a few weeks ago, received what we believed was a high temperature alarm (Constant Alarm) while coming off of plane at WOT to minimum wake zone. Immediately shut down engine, raised and checked foot for debris in intake, lowered and restarted without any alarm. Continued till next normal speed zone, went up on plane, 4000 RPM and ran another 15 minutes without issue. Backed down to minimum wake without alarm and ran at low RPM to anchor, where the alarm again sounded and was immediately shutdown. Entire time, good stream from tell-tale. Restarted, no alarm, headed back in, but found after a period of WOT that engine bogged down to 2800rpm with no alarm.
At advice of mechanic, replaced water pump (complete upper and lower housing and impeller-though old one was 2 seasons old and looked pretty good), both thermostats (they were pretty bad), and replaced poppet valve and seat. On re-launching and checks, good water flow without leaks to any gaskets visible, but same symptoms of no alarm and engine bogging at 2800 RPM after an extremely brief period of it running up to 4000. Occasionally can reproduce the power surge, but it immediately shuts back down.
Alarm is connected and beeps with ignition.
Performs normally in reverse and will go above 3000 rpm. Does the Guardian limit this? Is this not considered being under load and not an indicator of fuel or compression issues?
Carbs done 2 seasons ago, Stabil with every refill, Oil always topped off in secondary tank and empties appropriately. New Water/Fuel separator annually. New plugs.
We're on a waiting list for three weeks for our mechanic, who said to disconnect both temp sensors and if it still performed the same, it wasn't them-which we did without changes.
First, is it possible that we're dealing with a Guardian issue-will the engine ever limit without alarm? Manual says it might only with poor voltage, is that the only time that it will limit without alarm?
Second, will Guardian limit in forward and reverse or only forward gear? Trying to determine if we're barking up the wrong tree all together.
Any other ideas to try before hitting the mechanic? Not sure if this engine has a computer and if you can read codes. Haven't checked compression or spark-mechanic will have to do that.
At advice of mechanic, replaced water pump (complete upper and lower housing and impeller-though old one was 2 seasons old and looked pretty good), both thermostats (they were pretty bad), and replaced poppet valve and seat. On re-launching and checks, good water flow without leaks to any gaskets visible, but same symptoms of no alarm and engine bogging at 2800 RPM after an extremely brief period of it running up to 4000. Occasionally can reproduce the power surge, but it immediately shuts back down.
Alarm is connected and beeps with ignition.
Performs normally in reverse and will go above 3000 rpm. Does the Guardian limit this? Is this not considered being under load and not an indicator of fuel or compression issues?
Carbs done 2 seasons ago, Stabil with every refill, Oil always topped off in secondary tank and empties appropriately. New Water/Fuel separator annually. New plugs.
We're on a waiting list for three weeks for our mechanic, who said to disconnect both temp sensors and if it still performed the same, it wasn't them-which we did without changes.
First, is it possible that we're dealing with a Guardian issue-will the engine ever limit without alarm? Manual says it might only with poor voltage, is that the only time that it will limit without alarm?
Second, will Guardian limit in forward and reverse or only forward gear? Trying to determine if we're barking up the wrong tree all together.
Any other ideas to try before hitting the mechanic? Not sure if this engine has a computer and if you can read codes. Haven't checked compression or spark-mechanic will have to do that.
