1983 150HP Merc V-6, Need some basic help..

Hi new to this site, and thanks in advance for any help.

Just got a bass boat and we're blowing the main fuse inside the motor cowling. Boat shop charged me $178 and said nothing is wrong. Some wires just touched together below the console. Took it back out, blew two more fuses, and it seems to be getting hotter than I think it should. Please help

Can getting too hot cause this fuse to blow? I thought the trim switch was causing a short, but trim still has power after the fuse blows? Fuse kills power to all gauges and ignition switch.

1. Exactly what model # do I have, and what is the best repair manual?
Ser# is 6424221, I think it's model is 1150623 (XR-2, Marathon,??????) It's a 150HP v-6

2. Water seems to pee after 20 sec or so, but seems minimal. Should be more especially at idle. One side is hotter than the other. Can I simply pull the thermostats and run without them? Whats the worse thing that could happen without them?

3. Why does the water line off the T-stat "Tee" into the hose at the other T-stat then go down to another "tee" off the bottom before peeing out of the cowling? Shouldn't the cooling water enter the bottom and all come out the top T-stats?

4. All my experience is jet pumps. Is dropping the lower unit relatively easy (as with outboard jets)? Is there gearing or linkage that I might screw up as a newbe? I assume changing out the water pump impeller and assembly should be pretty easy???

5. Many threads mention the water perssure gauge. We have one. What should it be reading?????????????

6. I'm thinking of adding temp gauges to both sides of the power head. I don't think there is temp gauge on this one? Where would the temp gauge be if there was, and is it only connected to an alarm???

Thanks again

Re: 1983 150HP Merc V-6, Need some basic help..

might not be much help i,m sure someone with much more info will be along to help but these fuses blow when you start the engine? a bad stater soleniod may cause this the contacts become worwn and actually can weld together causing a short to all items connected to it when you turn on the key the lower water pump job is relatively easy and should be done every year or 2 even if not used the oil in the outdrive should be changed every year checking for a milky look to it means you have leaks and attention to seals gaskets should be given

Re: 1983 150HP Merc V-6, Need some basic help..

ambient tempature is required for some motor to function properly why pull them if there not the cause of the problem. it takes time for them to open but aparently they are according to your discrption rebuilding the water pump is more likely to be the problem here.

Re: 1983 150HP Merc V-6, Need some basic help..

1. Exactly what model # do I have, and what is the best repair manual?
Ser# is 6424221, I think it's model is 1150623 (XR-2, Marathon,??????) It's a 150HP v-6

Click to expand...

If you go to mercurypartsexpress.com there is a category on top that says "Search by Serial #" - go there, type in your serial number. If it is valid it will find you all of the assemblies for your particular engine as well as tell you what your model number is.

The best manuals you can get is the service manual from mercury. They are expensive from mercury though. If you search through the assemblies as mentioned above, you will find the general list of all the manuals (owners, service, parts, etc.). Get the part number of the service manual and then head on over to ebay; I found mine for $35.

4. All my experience is jet pumps. Is dropping the lower unit relatively easy (as with outboard jets)? Is there gearing or linkage that I might screw up as a newbe? I assume changing out the water pump impeller and assembly should be pretty easy???

Click to expand...

Extremely easy. After my first time doing it myself I felt a little foolish ever wondering what would have been so hard about it. Just follow the service manual or SELOC manual instructions for removal and reassembly - I would strongly urge you to follow the torque specifications for each bolt. Tightening the water impeller too much can damage it.

5. Many threads mention the water perssure gauge. We have one. What should it be reading?????????????

Click to expand...

The service manual from mercury will tell you explicitly what it should be.

Re: 1983 150HP Merc V-6, Need some basic help..

Your information on the engine is correct:

150 V-150XR2 V6 6220254 6443212 1983 USA

From here:

http://www.marinshopen.se/Motorer/O...Mercury2taktV6135175hp/tabid/490/Default.aspx

It is a model 1150623 and it is an XR2. parts here:

http://www.crowleymarine.com/mercury-outboard/575.cfm

The correct service manual for this engine is P/N 90-976583 which covers s/ns 5464486 thru 0C100860 and you can find it a several places online.

Gerry

Re: 1983 150HP Merc V-6, Need some basic help..

Thanks for your help. I would rather see water flowing free all the time than wait for a T-stat to open (partially or fully). It's just another moving part that can fail and over heat a good motor. I'm in favor of removing them entirely, just don't know if that will cause more problems.

I'll get the service manuals and start reading I guess. Thanks again.

Re: 1983 150HP Merc V-6, Need some basic help..

All the water for the tell-tale goes through the t-stats first. It is normal for a delay before it runs, and it is normal for it to be intermittent at idle when the water is cold.

That engine will cold-seize if you hit it hard when it is cold. The tell-tale tells you that it is up to operating temperature and it is OK to blast off. Learn to use it as intended. There is also an overheat alarm that will sound quickly if the head temperature gets too high.

The tell-tale only samples the t-stat flow. The rest goes down into the mid to cool the exhaust and flow out with it. Other streams come from permanent ports in the base plate, and from the poppet through the base plate.

The best instrument to tell the health of the cooling system is a water pressure gauge. Learn where it normally runs, and act if it begins to do something different. You can expect 2-6 lbs at idle, depending on the gauge mostly, and up to about 12 at 3000 rpm, where it will step back a bit as the poppet opens, then advance up to max, which will vary from engine to engine at WOT, probably around 20 on yours. If it's cooling and not sounding the alarm, then what it's doing is probably normal.

hope it helps
John

Re: 1983 150HP Merc V-6, Need some basic help..

Unfortuneatly you have inherited some one elses problems, electrical problems are hard to isolate and what you need to do is find out if your problem is on the boat side or the engine side, check all battery connections for proper tightness cleanliness, if you know how to do a voltage drop on the battery cables it may lead to something, if you take your meter leads put the + on the wire attached to starter and the negative to ground and crank the engine (be sure to disable the ignition by pulling the safety lanyard or by other means suggested) plugs have to be in, a healthy starter should read about 9.5 volts. You could rig up a circuit breaker in place of the fuse so you don't have to keep replacing fuses while testing and just keep wiggling/inspecting wires. It is a tough process and it could be costly but once you have verified where the problem exist it may be easier.

Re: 1983 150HP Merc V-6, Need some basic help..

Thanks for the info!!! I will search for that manual. The fuse isn't blowing right away. It starts and runs good, until everything heats up. After being on plane for about 10 minutes you can see the instrument panel looses power, and when you idle down to stop the motor dies (fuse is blown). This is another reason I'm thinking something is getting too hot?? Water is peeing the whole time, but becomes very weak at idle once you stop, almost intermittent. Thanks again for all the help, I appreciate it!!!!

Re: 1983 150HP Merc V-6, Need some basic help..

Heat from the engine and heat built up in a electrical circuit are seperate. Now heat can expand the isulation making it more malible and it could be touching the block somewhere. Inspect all red and black wires first. Could be a partially melted wire somewhere.