I got it cranked and running, but...

[livemusic]

It is a 1997 Tracker 40hp Pro17 boat. This motor looks identical to a Mercury of that vintage, I assume it is a Mercury motor.

 

After sitting up (too long!), I now have it cranked. I finally got it to crank but it would not stay running, ran rough and finally just quit. This motor has been a problem child ever since I bought the boat several years ago, often, a problem to start and a problem to keep it running without it running rough.

 

I disconnected the fuel line from where it goes into the gas tank and mixed up 1 gal of fresh, 93 octane e-free gas and added 3 oz of Seafoam (more than 'normal' can't hurt, right?) and also 2.6 oz of 50:1 2-stroke oil. The latter because I was not sure if the oil injection system would work and figured if it's working, too much oil won't hurt, just smoke a lot. Which it did. It wasn't but a few tries and I had it going good! It is now running great, seemingly smoother than ever, except... I first was not seeing water pee out and wondered where is the hole? I saw some ports in back and a little water was sputtering out but worried because it wasn't a pee. I finally located the water hose and deduced those ports in the back are exhaust? The water hose end fitting appeared to be a problem. I took the hose off the end fitting and the end fitting is toast, it looks like there is a very small rubber tube in there and it was rotted and was blocking water flow. I then cranked it again and it pee'd through the end of the hose a steady stream like I expected. Good strong flow.

 

I ran it a few minutes at a medium clip and felt of the water peeing out and noticed that it's real hot. Is this normal? I watched it awhile longer and the motor RPMs fluctuated a bit up and down, slowly, and the water stream slowed and then stopped peeing a few seconds. Then it started peeing again normally. Then it slowly slowed down again. I got scared at that point and shut it down. I felt of the motor and it was super hot. Is this normal or should the flow be steady and not fluctuate? What about the motor feeling super hot?

 

Also, there is a missing, round, plastic plug that is on top of the foot, I suppose water is going in there since the hole is open. Bad?

 

I am concerned about that water discharge, worried about the water pump. Hopefully someone can answer those questions above. TIA.

[Kirtley Howe]

Does this motor have a thermostat? Sound to me like the thermostat (assuming it has one) is not opening up soon enough and is not staying open when the motor is warmed up. If it does have a thermostat, it should be cheap and easy to replace. Good luck.

[livemusic]

24 minutes ago, Kirtley Howe said:

Does this motor have a thermostat? Sound to me like the thermostat (assuming it has one) is not opening up soon enough and is not staying open when the motor is warmed up. If it does have a thermostat, it should be cheap and easy to replace. Good luck.

 

I did a search and found a thread where someone says a 4-cyl 1997 Mercury 40hp does not have a thermostat. (I am, again, assuming that my Tracker 40hp is made by and same as Mercury.)

[Woody B]

I suspect there's a problem with the water pump impeller.   Not a super hard fix.  A coworker has a 1995 Tracker Panfish with a 40.  It is a Mercury engine with Tracker branding.  IIRC he had problems with a coil, or coils once.  His had been sitting for a while when he got it.  He's bypassed the oil injection....mixes oil and gas.  He had to do something to bypass the oil injection alarm though.   

[livemusic]

30 minutes ago, Woody B said:

I suspect there's a problem with the water pump impeller.   Not a super hard fix.  A coworker has a 1995 Tracker Panfish with a 40.  It is a Mercury engine with Tracker branding.  IIRC he had problems with a coil, or coils once.  His had been sitting for a while when he got it.  He's bypassed the oil injection....mixes oil and gas.  He had to do something to bypass the oil injection alarm though.   

 

How can one tell if the impeller is the problem? Can it be replaced or do you have to replace the entire water pump? The seller to me told me that they replaced the water pump. But that was several years ago. (Which is when I bought it.)

[Bird]

I'd put the boat on the water and give it a good run.

 

 

[TnRiver46]

You don’t want the motor or the water coming out the telltale to be hot. Very warm yes and maybe hot after you drove a mile or 3. Mine used to beep an alarm after I trolled at idle speed for a while and that water coming out was boiling hot when it would beep. Just warmish when it’s functioning normally 
 

sounds to me like she’s overheating, then again I would think a 1997 would beep if overheated 

[airshot]

Replace the water pump before you try running it again !!!!!   Check to see if any vanes have broke off the impellor, if so they could be blocking the cooling system and need to be removed/ flushed out !!!  I woukd also run a compression check to see if the motor is good !!  Boat motors are no place to cut corners in repairs and get your self a " factory" service manual, found mine on Ebay !!  

[Way2slow]

If all this was done on muffs, I'm surprised you didn't blow it up.  For starters, you should never run a motor at more than 2,000 rpm when not under a load. Two strokes can go into runaway just like a diesel engine. 

Doing that on muffs, the muffs on a hose most likely were not supplying enough water.  I run them in a 120-gallon stock tank so the water pump can provide the water needed and even then, when the prop is turning, the water turbulence will let it suck air into the water intake ports.

Since circulates the water through the block, it exits through the exhaust so you should be seeing water coming out of those holes.

Water pumps impellers should be replaced a lot more often than "many years".  Three years is pretty much ther recommended standard.

If the motor has ever been run in salt water, and has sat for long periods, it's a good chance the corrosion has clogged the cooling ports in the block.

You not knowing anything about a water pump, I'm not even going to get into the mix on diagnosing your problem.  Besides that, I'm not overly familiar with Mercury motors anyway to get into specific/detailed trouble shooting.  

One thing I forgot to mention, that hole you referred to on top of the lower unit is most likely just the access hole for a speedometer supply hose.  When they provided that feature, there is a plastic nipple screwed into the leading edge of the lower unit and that's an access hole to get the tube down to it.  Not having a plug in it has absolutely not affect on the water circulation.

 

[airshot]

On 7/2/2023 at 12:16 PM, livemusic said:

It is a 1997 Tracker 40hp Pro17 boat. This motor looks identical to a Mercury of that vintage, I assume it is a Mercury motor.

 

After sitting up (too long!), I now have it cranked. I finally got it to crank but it would not stay running, ran rough and finally just quit. This motor has been a problem child ever since I bought the boat several years ago, often, a problem to start and a problem to keep it running without it running rough.

 

I disconnected the fuel line from where it goes into the gas tank and mixed up 1 gal of fresh, 93 octane e-free gas and added 3 oz of Seafoam (more than 'normal' can't hurt, right?) and also 2.6 oz of 50:1 2-stroke oil. The latter because I was not sure if the oil injection system would work and figured if it's working, too much oil won't hurt, just smoke a lot. Which it did. It wasn't but a few tries and I had it going good! It is now running great, seemingly smoother than ever, except... I first was not seeing water pee out and wondered where is the hole? I saw some ports in back and a little water was sputtering out but worried because it wasn't a pee. I finally located the water hose and deduced those ports in the back are exhaust? The water hose end fitting appeared to be a problem. I took the hose off the end fitting and the end fitting is toast, it looks like there is a very small rubber tube in there and it was rotted and was blocking water flow. I then cranked it again and it pee'd through the end of the hose a steady stream like I expected. Good strong flow.

 

I ran it a few minutes at a medium clip and felt of the water peeing out and noticed that it's real hot. Is this normal? I watched it awhile longer and the motor RPMs fluctuated a bit up and down, slowly, and the water stream slowed and then stopped peeing a few seconds. Then it started peeing again normally. Then it slowly slowed down again. I got scared at that point and shut it down. I felt of the motor and it was super hot. Is this normal or should the flow be steady and not fluctuate? What about the motor feeling super hot?

 

Also, there is a missing, round, plastic plug that is on top of the foot, I suppose water is going in there since the hole is open. Bad?

 

I am concerned about that water discharge, worried about the water pump. Hopefully someone can answer those questions above. TIA.

If toward the rear of the motor, probably the hole to adjust the trim tab....see if there is a bolt head down in there !!  Running on a hose does not test the water pump !!  The hose pressure will force some water thru the system but will cause overheat issues at high rpm.  The water pump needs replaced or ruin your motor....that simple !!!

[livemusic]

I own ear muffs that you use with a water hose but did not use it, I used a large plastic barrel filled with water. I never put the motor into gear, it stayed in neutral but even at that, I wondered about circulation in the barrel. Imagining that turbulence might keep it from getting good water supply. I used the barrel because I figured it would be more realistic.

 

I also did not run the motor at high RPMs. I said medium but my tach might be broke, not sure, but it was not a high throttle. My tach was giving a reading, of 1200 RPMs up to 1400 RPMs but then when I stopped, it didn't go to zero. Seems it should. Maybe it is just dragging.

[thomas15]

On 7/2/2023 at 1:33 PM, livemusic said:

 

I did a search and found a thread where someone says a 4-cyl 1997 Mercury 40hp does not have a thermostat. (I am, again, assuming that my Tracker 40hp is made by and same as Mercury.)

 

I'm not trying to pile on here just adding my 2 cents. 

 

I urge you to find out exactly what motor you have please stop assuming or trusting in what other people say. As I mentioned and others have also, it is a great idea to get the factory service manual for this motor. It is not going to cost that much and being stuck 5 miles from the boat ramp sucks under any conditions so for me at least having my motor running at the peak is my way of reducing the odds this will happen to me.

 

In simple terms, the water pump is an impellor inside a metal housing. To access it you probably have to drop the outdrive (lower unit), remove a few screws then remove the impellor, replace, put back together. As long as there are no score marks on the housing replacing the impeller should be enough. The impellor itself usually is not expensive. 

 

A few comments. First the vanes of the impellor must be pointed in the correct direction. Second, you will probably have to disconnect the shift linkage to remove the outdrive so this is something that you need to understand (correct adjustment). And just given the information presented in this thread even of the person who sold you the boat swore on his mothers grave that he replaced the water pump I would go ahead and replace it again because this is so vital and if it fails can be a very costly situation and inconvenient to remedy.

 

Beyond the water pump if it were my motor I would also do a compression check, rebuild the carbs, adjust and sync the carbs and ignition timing, replace the sparks plugs, verify the oil injector and drain and replace the lower gear oil. For me, my boat is a hobby, it is a want, not a need. If I have any questions or doubts in my mind about the safety or reliability, I fix the problem before my next fishing trip, I'm quite conservative in that regard.

 

Part of this goes back to when I was a kid, we lived at the Jersey Shore where everyone has a boat. We were about 2 miles off shore in the Atlantic Ocean off Belmar when we couldn't get our motor to start. After much hair pulling we got it to limp back but the experience left a scar. Even in my little home lake and after 50+ years since I do not play footsy with my boat motor. I see people all the time and you will also, people at the ramp (as an example) with the cover off manually priming with a squirt bottle just to get away from the dock. This is not something I personally would do because it indicates that there is something that needs to be fixed.