Merc90HPnewbie
Petty Officer 2nd Class
- Joined
- Jul 27, 2003
- Messages
- 178
I actually followed the advice in the post that advises newbies on what to do before posting a message. I read through a lot of messages on this board and it sounds like a lot of people have the same basic problem... overheating, or at least hearing the overheating warning and not being sure what's going on. I found 5-10 messages on this topic within the last few days! I actually learned a lot reading through this board, though, and it's changed my original question around now that I know a little more about what's going on (I.E. the technical term for 'cooling water pump output stream' is 'pee hole' !! 
<br /><br />It sounds like I might be having this EXACT same problem:<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=29;t=008299 <br /><br />OK just a little background here; Got a 16 ft fiberglass bowrider runabout recently (it's an 1985 Glasstron). I have only a little previous boating experience - bascially what I remember as a kid from going out on my friend's father's boat, helping to launch it, etc. The motor is a 90HP Mercury outboard which I believe is 1985 just like the boat or possibly a bit newer. I believe it's a straight 6. I just finally got to put it in the water this past weekend. Everything went pretty well (got the thing into and out of the water faster than the old pros except for one problem. Here's the day's events: I was going about 5MPH for a few hundred yards out of a small creek, then I got to the lake and opened up the throttle just a bit (first time out and all), we didn't go more than about 16MPH for about 30 mins or so (the boat has a dedicated speedometer in the instrument cluster that uses a small paddle wheel mounted low on the transom, it seems to be pretty inaccurate at low speeds, but there is a fishfinder that has a speed readout as well, I used that most of the time (at low speeds, the mechanical speedo always seemed to think we were going about 10MPH). I had been told to watch the stream of water that is the output from the water pump and make sure it's always flowing. After scooting around in the river for a while, I let the wife drive (there was another couple on the boat too) and I went aft to look at the motor and check the gas level. I looked for the stream of water and it was just a 'spray' with some 'smoke' coming off it. I started to rationalize "well maybe we are going fast enough that the wind is breaking the stream up into a spray, and the 'smoke' is just steam because the water is hot". I quickly ran my hand thru the spray and it was very hot! You couldn't leave your hand there... I'm a bad guesser but I would say it was over 130 degrees F. I called a friend who has a boat and asked him. He says it's normal at higher speeds - the water is hot enough that it just comes out as steam - and the smoke is probably exhaust. Again, I'm no expert here but I thought that the stream of water was just cooling water, and that the exhaust gases come out of the center of the hub where the prop is (underwater). He says 'well, what you saw is just water turning to steam then". Something about it still bothers me though. I throttle down to a crawl and head back to the ramp. Slowly the 'stream' comes back, going from a mist to a spray, to a trickle of liquid , and then back to a stream. We throttle up a little bit (arond 2000RPM) and the stream gets a little thinner and with some accompanying spray and I start hearing a beeping. It was a low piezoelectric beep --- beep --- beep --- like the alarm on a wristwatch. I dismissed it as the fishfinder that I dont know how to use (remember I just bought this boat). The beeping stops on its own and we make it back to the ramp and back home with no problem. By the way whenever I throttled down to let the engine rest or cool off, water would flow forward a bit - I guess it was the water from my collapsing wake - and hit the engine and evaporate. I didn't like this but there was not much I could do. I guess going faster would allow me to get up on plane and get the enginer further from the water? (yes I remembered to put the plug in the boat and no, it's not sitting low because the bilge is full of water Also the first owner had put a 'Happy Troller" plate on, I fiddled with it for a while and my guess is that it allows you better control by folding down and blocking the prop - you can move slower at higher RPMs. But, it looked (to me, the clueless newbie) like the boat's attitude was wrong - too low (again,maybe I was just going too slow). I played with trim up and down but it didn't make much difference. So I'm wondering- could this stupid plate be causing me problems? Should I take it off? (I don't feel the need to go trolling any time soon Anyway, later I go back to my 'Boating for Dummies' book (you didn't think I knew what a 'transom' was on my own, did you?) and did some more reading. 'Apparently' there's often an overtemperature alert on boats that beeps at you to let you know of impending doom. (I learned that from the book and reading here) Also I read the fishfinder manual and there doesn't seem to be any reason for it to beep except for the 'shallow water' alarm. And I looked at the finder when it was beeping and we were in 35 foot deep water - and the thing DIDN'T beep when we were in 5-10 feet of water. SO! My question is; assuming I didn't get a plastic bag or something wrapped around the lower unit, what could be the problem here with the cooling water and what should I look for? Did I just overreact like a nervous first time father or is there something here worth investigating?<br /><br />Reading the newbie hints it also said to get a service manual for your engine. I was thinking along those lines already. There seem to be ones made by Clymer, Seloc, and Chilton's.(what, no Haynes?) and I guess there are original model-specific ones made by Mercury. At some point I will order the one direct from Mercury but I anticipate it will take some time. In the meantime, can anyone recommend one of the 'universal' books as better than the rest?<br /><br />I guess I would know this if I had the manual, but does anyone have a guess if this model year has an automatic oil injection tank or not? I took off the engine top cover and cowling and looked around, but I barely understand what I am looking at (honestly before I read the Boating for Dummies I thought boat engines were all 4 stroke). I didn't see anything that looked like an oil tank but maybe I looked in the wrong places. I found a quart of 2 stoke oil near the gas tank. I called the previous owner to ask him how he handled the oil (premix or tank) but he was a little clueless, he said he just mixed a full bottle of oil with a full tank of gas. From what I've read this engine should take 50:1 premix. One marine tech mentioned it might have (or have had removed) an "Autoblend" but I didn't see a seperate tank for that. <br /><br />Also I read in a lot of the other posts that people knew their engine temp and water pressure. The only gauges I have are speed and RPMs. <br /><br />I just called the local marina and they have the SELOC manual and impeller kit for this boat. I guess I'll be checking that out then, unless someone says the Clymer or another is much better.<br /><br />OK there's a lot of my yammering above, here's my questions in Clff's Notes form:<br /><br />1)Could the faint beep - beep - beep I heard be the overtemp alarm? It seemed to be coming from the console or throttle control area. I'm a bit confused on this. Are there two seperate alarms? One up front and one on the engine? Do they activate at the same temperature? Is one a pre-warning? I read that the beeper up front is tested when you first start the engine. I did not notice this but I will listen next time I start it.<br /><br />2)GIVEN that the tell tale stream is coming out fine at lower RPMs (wouldn't this lead one to assume the impeller and water pump are poerating correctly?) what could cause the stream to break up at higher RPMs? <br /><br />3)Should any smoke/vapor/steam/exhaust/whatever be coming out the telltale/pee hole?<br /><br />4)Is it common for water to come up over the transom and steam off the motor when going from 15MPH down to 5MPH?<br /><br />5)Does the 'happy troller' plate adversely affect anything when it is in the 'up' position? Should I pull it off or let it be?<br /><br />6)What's the best service manual to get?<br /><br />7)Any guess on whether this engine is supposed to have oil injection or not? Or would you need the serial number to know that?<br /><br />8) What do I have to do to add a temperature gague to the engine? Seems like this is a real critical number to watch. Can I tap off whatever sensor is used to set off the overtemperature alarms? If not, is there some other sensor that already exists that I can use?<br /><br />9) I have heard references to a water pressure sensor as well. Where exactly is this water pressure measured? Just the pressure of the cooling water running through the head and out the telltale? Again is there something already present in the motor that I can connect a gauge to? Or at least an existing hole where I can remove a cap and install a sensor? Or is it a huge job where I have to drill into the head???<br /><br />Thanks a lot for helping out this confused newbie!!!<br /><br />(whew-kept it under 10 questions....
<br /><br />It sounds like I might be having this EXACT same problem:<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=29;t=008299 <br /><br />OK just a little background here; Got a 16 ft fiberglass bowrider runabout recently (it's an 1985 Glasstron). I have only a little previous boating experience - bascially what I remember as a kid from going out on my friend's father's boat, helping to launch it, etc. The motor is a 90HP Mercury outboard which I believe is 1985 just like the boat or possibly a bit newer. I believe it's a straight 6. I just finally got to put it in the water this past weekend. Everything went pretty well (got the thing into and out of the water faster than the old pros except for one problem. Here's the day's events: I was going about 5MPH for a few hundred yards out of a small creek, then I got to the lake and opened up the throttle just a bit (first time out and all), we didn't go more than about 16MPH for about 30 mins or so (the boat has a dedicated speedometer in the instrument cluster that uses a small paddle wheel mounted low on the transom, it seems to be pretty inaccurate at low speeds, but there is a fishfinder that has a speed readout as well, I used that most of the time (at low speeds, the mechanical speedo always seemed to think we were going about 10MPH). I had been told to watch the stream of water that is the output from the water pump and make sure it's always flowing. After scooting around in the river for a while, I let the wife drive (there was another couple on the boat too) and I went aft to look at the motor and check the gas level. I looked for the stream of water and it was just a 'spray' with some 'smoke' coming off it. I started to rationalize "well maybe we are going fast enough that the wind is breaking the stream up into a spray, and the 'smoke' is just steam because the water is hot". I quickly ran my hand thru the spray and it was very hot! You couldn't leave your hand there... I'm a bad guesser but I would say it was over 130 degrees F. I called a friend who has a boat and asked him. He says it's normal at higher speeds - the water is hot enough that it just comes out as steam - and the smoke is probably exhaust. Again, I'm no expert here but I thought that the stream of water was just cooling water, and that the exhaust gases come out of the center of the hub where the prop is (underwater). He says 'well, what you saw is just water turning to steam then". Something about it still bothers me though. I throttle down to a crawl and head back to the ramp. Slowly the 'stream' comes back, going from a mist to a spray, to a trickle of liquid , and then back to a stream. We throttle up a little bit (arond 2000RPM) and the stream gets a little thinner and with some accompanying spray and I start hearing a beeping. It was a low piezoelectric beep --- beep --- beep --- like the alarm on a wristwatch. I dismissed it as the fishfinder that I dont know how to use (remember I just bought this boat). The beeping stops on its own and we make it back to the ramp and back home with no problem. By the way whenever I throttled down to let the engine rest or cool off, water would flow forward a bit - I guess it was the water from my collapsing wake - and hit the engine and evaporate. I didn't like this but there was not much I could do. I guess going faster would allow me to get up on plane and get the enginer further from the water? (yes I remembered to put the plug in the boat and no, it's not sitting low because the bilge is full of water Also the first owner had put a 'Happy Troller" plate on, I fiddled with it for a while and my guess is that it allows you better control by folding down and blocking the prop - you can move slower at higher RPMs. But, it looked (to me, the clueless newbie) like the boat's attitude was wrong - too low (again,maybe I was just going too slow). I played with trim up and down but it didn't make much difference. So I'm wondering- could this stupid plate be causing me problems? Should I take it off? (I don't feel the need to go trolling any time soon Anyway, later I go back to my 'Boating for Dummies' book (you didn't think I knew what a 'transom' was on my own, did you?) and did some more reading. 'Apparently' there's often an overtemperature alert on boats that beeps at you to let you know of impending doom. (I learned that from the book and reading here) Also I read the fishfinder manual and there doesn't seem to be any reason for it to beep except for the 'shallow water' alarm. And I looked at the finder when it was beeping and we were in 35 foot deep water - and the thing DIDN'T beep when we were in 5-10 feet of water. SO! My question is; assuming I didn't get a plastic bag or something wrapped around the lower unit, what could be the problem here with the cooling water and what should I look for? Did I just overreact like a nervous first time father or is there something here worth investigating?<br /><br />Reading the newbie hints it also said to get a service manual for your engine. I was thinking along those lines already. There seem to be ones made by Clymer, Seloc, and Chilton's.(what, no Haynes?) and I guess there are original model-specific ones made by Mercury. At some point I will order the one direct from Mercury but I anticipate it will take some time. In the meantime, can anyone recommend one of the 'universal' books as better than the rest?<br /><br />I guess I would know this if I had the manual, but does anyone have a guess if this model year has an automatic oil injection tank or not? I took off the engine top cover and cowling and looked around, but I barely understand what I am looking at (honestly before I read the Boating for Dummies I thought boat engines were all 4 stroke). I didn't see anything that looked like an oil tank but maybe I looked in the wrong places. I found a quart of 2 stoke oil near the gas tank. I called the previous owner to ask him how he handled the oil (premix or tank) but he was a little clueless, he said he just mixed a full bottle of oil with a full tank of gas. From what I've read this engine should take 50:1 premix. One marine tech mentioned it might have (or have had removed) an "Autoblend" but I didn't see a seperate tank for that. <br /><br />Also I read in a lot of the other posts that people knew their engine temp and water pressure. The only gauges I have are speed and RPMs. <br /><br />I just called the local marina and they have the SELOC manual and impeller kit for this boat. I guess I'll be checking that out then, unless someone says the Clymer or another is much better.<br /><br />OK there's a lot of my yammering above, here's my questions in Clff's Notes form:<br /><br />1)Could the faint beep - beep - beep I heard be the overtemp alarm? It seemed to be coming from the console or throttle control area. I'm a bit confused on this. Are there two seperate alarms? One up front and one on the engine? Do they activate at the same temperature? Is one a pre-warning? I read that the beeper up front is tested when you first start the engine. I did not notice this but I will listen next time I start it.<br /><br />2)GIVEN that the tell tale stream is coming out fine at lower RPMs (wouldn't this lead one to assume the impeller and water pump are poerating correctly?) what could cause the stream to break up at higher RPMs? <br /><br />3)Should any smoke/vapor/steam/exhaust/whatever be coming out the telltale/pee hole?<br /><br />4)Is it common for water to come up over the transom and steam off the motor when going from 15MPH down to 5MPH?<br /><br />5)Does the 'happy troller' plate adversely affect anything when it is in the 'up' position? Should I pull it off or let it be?<br /><br />6)What's the best service manual to get?<br /><br />7)Any guess on whether this engine is supposed to have oil injection or not? Or would you need the serial number to know that?<br /><br />8) What do I have to do to add a temperature gague to the engine? Seems like this is a real critical number to watch. Can I tap off whatever sensor is used to set off the overtemperature alarms? If not, is there some other sensor that already exists that I can use?<br /><br />9) I have heard references to a water pressure sensor as well. Where exactly is this water pressure measured? Just the pressure of the cooling water running through the head and out the telltale? Again is there something already present in the motor that I can connect a gauge to? Or at least an existing hole where I can remove a cap and install a sensor? Or is it a huge job where I have to drill into the head???<br /><br />Thanks a lot for helping out this confused newbie!!!<br /><br />(whew-kept it under 10 questions.... 
