mercury optimax 225 temp sensor alarm

[Durbijd]

Thanks Don. I kind of feel like it mat be time to go ahead and replace the thermostats anyway. I'm going to ask the original owner of the boat when the last time he had them changed. The motor only has 270 hours on it but It is a 2004 so maybe I should just replace them and eliminate that possibility? it didn't look like the stats themselves were that expensive. I dont have a lot of experience with outboard motors but I do have some mechanical aptitude. How hard are they to replace on your own? about how much would a typical bill be for a shop to do it? He already checked and eliminated the poppet valve. after talking to him today he wants to know what I am Idling at and thinks we may need to bump the idle up a bit. So I was thinking of getting out on the water and trying to get all of that information for him. He has the same motor as mine and says if he idles for a while then even his alarm will go off.

[Savage]

Thermostats are easy to change.

The computer controls the idle speed, so it can NOT be bumped up.

You friend has a problem also if his alarm is going off. He needs to get it fixed.

[Durbijd]

Thermostats are easy to change.

The computer controls the idle speed, so it can NOT be bumped up.

You friend has a problem also if his alarm is going off. He needs to get it fixed.

savage this is the guy that was working on my boat and runs the the boat shop closest to me. only one within an hour that ill step into actually. I was reading the idle is controlled by the ecm but I didn't know if there was a way to adjust the ecm. I was just thinking too...i find it a bit weird that i asked him last time to do the frame by frame and if anything seems out of ordinary change the stats. Shouldn't the frame by frame printout show him the rpm at idle as well as anything else? and is that just for the last run or how does that actually work.

[Savage]

Idle speed can NOT be changed...….A good Mercury Tech should know this.

[Durbijd]

I don't know if he was talking about in gear while trolling or what. I agree though. I think you and Don are on the right track with the thermostats. I really do appreciate your guys input and knowledge. Think I'm gonna take it to someone else. Problem is that everyone getting busy now. Do you think it would be ok to run till someone can look at it as long as I am not idling long enough to bring the temp up? That's where the overheat issue is and the boat runs perfect otherwise and never throws an alarm under throttle. Appreciate the info. I'm new to the bigger motors with fuel injection. Last motor I had was a Johnson 90 so I am trying to educate myself as well knowledge is power.

[Savage]

The thermostat/temperature issue must be addressed before running the motor on plane again.

[Durbijd]

So I took it to another dealer. After about a week and a half they finally got to my boat this is a busy time of year especially for the northern part of the states. They did find a few grains of sand but nothing that should have held them open that bad temp was reading 106 on one stat and i think 112 on the other according to the freeze frame at idle. Ill check when I get the printout of the run history. Called the last owner of the boat and they replaced them 3 years ago. They suggested replacing the stats and I agreed but they didn't have them in stock it would likely be 3-4 days on getting them in...that was last Tuesday. I am wanting to call them and get an update as I thought I would have heard something by now. I don"t want to be that guy though I have called them twice already once to see if they looked at it and once last Friday to see if they had worked on it or gotten the parts in. We are getting into some good crappie weather here and a big tournament next weekend. sorry for the vent but I did also have a question too. How long should thermostats last and how much debri can cause them not to want to close?

[Savage]

There is no life expectancy on thermostats.....A couple of grains of sand in the wrong place can cause them to fail.

[SilverFox579]

There is no life expectancy on thermostats.....A couple of grains of sand in the wrong place can cause them to fail.

^^^^

A dealer telling you that a few grains of sand was nothing that should have held them open, hmm. Well documented here that's ALL it takes to hang a stat.

[Durbijd]

Ok I called again because they still have not called me about my motor being done. THey said the thermostats are on backorder. so I was looking and found two part numbers it looks like both will work but one is 100$ and the other is around 60$. again engine is a 2004 optimax 225 serial number is oT973057. here are the part numbers I am finding.

885599004 thermostat
8M0057307 thermostat
8503181 gasket.

Also would be nice to have a service manual and am thinking I could pick my boat up and do this myself. I have found a few places I can get either part number. They have had my boat for almost a month now. Two weeks ago the mechanic told me that he would order the parts and that they should arrive in 2-3 days. two weeks later I call them to find out they are on backorder and they never attempted to reach me and give me an update. Looks like my boat is going to be out of commission for a third tournament I had planned to fish now. Don I sent your staff an email inquiring the correct parts I need. My apologies for doubling up but I am really getting frustrated.

[lpugh]

It would be wise to learn how to service the stats and poppit valves yourself. I have had to clean my stats 5 times this year, every time it has been on lake oroville it picks up small trash do to the fire they had. The ash and small chip runoff has been horrible. Genuine mercury stats are of very good quality and can be cleaned repeatedly if not damaged by picking up sand. Thinking I should also do the water pump soon do to all this debris being passed through it even though it only has about 30 hours on it

[SilverFox579]

Ok I called again because they still have not called me about my motor being done. THey said the thermostats are on backorder. so I was looking and found two part numbers it looks like both will work but one is 100$ and the other is around 60$. again engine is a 2004 optimax 225 serial number is oT973057. here are the part numbers I am finding.

885599004 thermostat
8M0057307 thermostat
8503181 gasket.

Also would be nice to have a service manual and am thinking I could pick my boat up and do this myself. I have found a few places I can get either part number. They have had my boat for almost a month now. Two weeks ago the mechanic told me that he would order the parts and that they should arrive in 2-3 days. two weeks later I call them to find out they are on backorder and they never attempted to reach me and give me an update. Looks like my boat is going to be out of commission for a third tournament I had planned to fish now. Don I sent your staff an email inquiring the correct parts I need. My apologies for doubling up but I am really getting frustrated.

Call Rhonda @ European Marine to order a genuine service manual and thermostats/gaskets for your engine, be sure and mention you are a BBC member so you get the BBC member discount - If you want to order or price Mercury Engine Parts or Accessories...

[Durbijd]

New thermostats installed. They seem to be operating normally. I can see the coolant temp cycle up to about 134 and then back down to 116-117 then back up. I am still getting an alarm for thermostats but only after the first startup of the day. Is there something else I may be missing or should be worried about? This last time I saw it cycle through twice before an alarm and the vesselview mobile was showing 122 deg at that time. Rpm was 580-600 and water pressure was 4.3 psi according to vvm

[Savage]

New thermostats installed. They seem to be operating normally. I can see the coolant temp cycle up to about 134 and then back down to 116-117 then back up. I am still getting an alarm for thermostats but only after the first startup of the day. Is there something else I may be missing or should be worried about? This last time I saw it cycle through twice before an alarm and the vesselview mobile was showing 122 deg at that time. Rpm was 580-600 and water pressure was 4.3 psi according to vvm

How are you sure that the alarm is for "thermostats"? What exactly does the fault state as the alarm is going off?

[Durbijd]

Alarm says thermostats as the title. Then when you open it up it says coolant temperature relative to a specific threshold. The value is to low

[Durbijd]

It comes on. It had 3 short beeps this time. Then looked at the vvm and the alarm wasn't in the observed faults but had the triangle so I tapped on it and brought up that fault.

[Savage]

You need to have a Dealer check the temperatures of each cylinder individually with a CDS.....you still have an issue going on. The temperature reading that you are getting on the display is the AVERAGE of TWO sensors. Dealer can see the TRUE reading of each cylinder.

[Durbijd]

Savage even though this only happens very first start of the day? I idled a long time when we got back to the ramp and it never did beep again. I just got it back from the dealer who said they had it at idle for around 30 minutes with no fault.

[Durbijd]

Savage even though this only happens very first start of the day? I idled a long time when we got back to the ramp and it never did beep again. I just got it back from the dealer who said they had it at idle for around 30 minutes with no fault.

[Savage]

Yes, when a alarm is sounding its telling the operator something IS wrong (STILL). Don't ignore it because the results can be catastrophic.