Newb - Merc 3.0 overheat issues, throttle control, & trim pump.

Bakeys

Seaman
Joined
Jun 14, 2012
Messages
63
OK, let's get it over with. I'm a newb and I've made some interesting errors in the past few days.:facepalm:

'88 Stingray with Merc 3.0 / Alpha One.

In my enthusiasm to get our "new" boat on the water, I overheated it. :facepalm:

On it's shakedown cruise, my wife and I launched at the canal to see if the boat was going to operate satisfactorily.

Throttle control - for some reason the 'throttle only' control isn't operable. Push the button in and you get nothing. Still can't move the throttle control forward. In drive it works fine. So, it takes me a few minutes to get it started because I can't increase the throttle position. (Stupid!)

Boat's runnin! We go a few hundred yards to the west and turn around, go a few hundred yards to the east and keep an eye on the gauges and all. I watch the temp creep up. Next thing I know it's at 200 and still going. I wasn't too worried. (Suffice it to say I hadn't read the operating temp threads yet.) Up to 220 and I figure things are getting a bit hot. I turn around again and head in the boat launch direction. Now I've got steam coming from the engine compartment. So I shut her down. Sure enough, a rather warm jet of steam is blowing out of a crack in the exhaust manifold.

An hour or so later, we're back at the dock - have you ever paddled an 1,800 rowboat before? I'm thoroughly annoyed, disappointed, and disgusted with myself for my actions. I allowed my enthusiasm and emotions to take priority over sense and sensibility.

So here's my dilemma:
How do I fix it? I'm suspecting a water pump rebuild kit and a thermostat is in my immediate future. As far as the manifold goes, is it fixable or have I thrown myself my very own sausage party?:eek: I hate to suggest this, but is it weldable?

Throttle control - - what is goin' on there? :confused: I've had the square plastic button off and see a round post like doodad that pushes in but doesn't actually do anything. I know it's supposed to override the drive function and allow you to control throttle only. But mine ain't doing that! Suggestions? I don't know the brand name but it's a single lever style with the up/down trim switch and the square "trailer" switch on the vertical rise. The square "throttle only" button is below the two trim switches.

Speaking of trim - When I first put a battery in it, I could hear a solenoid click when the trim button was actuated. (Not the trailer button however.) The trim pump would not start. I jumpered from the battery positive straight to the blue/white (as directed by the manual / troubleshooting chart) and the motor started and the outdrive went up. Outdrive went down on the green/white wire. So from a functionality perspective, the trim pump is doing what it's supposed to do, except running from the trim control on the stick. Note: after doing the jumper test, I now now longer hear the solenoid click from the control switch on the stick. (20 amp main fuse is fine).


Thanks in advance for the help, fellas.
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,345
Re: Newb - Merc 3.0 overheat issues, throttle control, & trim pump.

trim issue most likely the solenoid or its connections are bad.remove wires and clean everything.

control box may just be defective or the handle is not in the neutral detent , what you think is neutral is not really control box detent neutral

Go up in the Adults Only section and look at some of the sticky`s , a wealth of info there. operator , engine and drive manuals

cracked manifold is a horse and barn door riddle. either you did it from the overheat or it was already present .I assume no pre-sale water test was performed.
Damage is most likely:
head gasket, warped head, cracked head
exaust shutters
exaust coupler boots
water pocket cover in drive
any wires /cables laying on/near the exaust pipe melted/fused/. damaged
water pump in drive
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Newb - Merc 3.0 overheat issues, throttle control, & trim pump.

ok.. First up you're going to need these

Engine service manual -> https://docs.google.com/open?id=0B1TAvwZ3TjhfUVREOHFDUGZRR1NDelg5blYybmNRdw
Drive service manual -> https://docs.google.com/open?id=0B1TAvwZ3TjhfOVRUNEk0anBUR3lQYTkwcUh5RElUQQ
Controls Manual -> https://docs.google.com/open?id=0B1TAvwZ3TjhfZDJiNjc5YzAtYzBhYy00MjlmLTg5NzktMjQyZDJhMGQ3YzQ1

Download and SAVE them... They are the Merc service manuals for your engine, drive and control box...

Have a gander at my videos, you're going to need some or all of them too...

Removing drive: http://youtu.be/w3O63YTOhn8
Checking alignment: http://youtu.be/w118LGsYgY4
Installing drive: http://youtu.be/aGVrY4cWiDA
Shift cable adjustment: http://youtu.be/-s_tgevX2aI

Let's deal with the issue one at a time..

Trim should be the first (it's easy and you need to raise and lower the drive before you can do much else).
Grab a test light and start with the circuit diagram (in the drive manual). Make sure you have power up to the control handle (that will be on the red wire). Then make sure the switch is feeding power to the appropriate solenoid control wire (just remember the the sky is blue, so the blue wire will be UP, and grass is green, so the green wire is DOWN)...

The overheat... You should start with pulling the drive, splitting it and checking (most likely replacing) the water pump... If the housing has been even remotely hot, that and the pump base will need to be replaced. Then check up inside the bottom of the top box for the water pocket cover... (read all about that right here -> http://forums.iboats.com/showthread.php?t=556903&p=3825409&viewfull=1#post3825409)

The cracked manifold... You MIGHT get someone to weld it, but you need to check if the crack extends inside. If it does, replace it...

Throttle only button... Pull the control box off and take it apart CAREFULLY... There can be a pita to put back together.... But if you have 35 years as a watchmaking master, it shouldn't take more than a few days.... No, they're not really that bad... Just a bit finicky. I pull mine apart every few years and give it a good greasing, so it can't be that hard....

I think we got everything....

Good luck (and those manuals are your new best friends, and us here;))

Chris.........

oh, and welcome to iBoats....
 

Bakeys

Seaman
Joined
Jun 14, 2012
Messages
63
Re: Newb - Merc 3.0 overheat issues, throttle control, & trim pump.

Well Bt Doctor and AChris, I'd like to personally thank you each for your consideration in my dilemma. I was hoping this forum would prove to be helpful. I am not disappointed.

Seems like I have a bit of an elephant to eat. So I will be grabbing my fork and eating said elephant one bite at a time. Will most likely start with the trim situation as it doesn't require a water pump or thermostat installation which I don't have parts for.

I had a quick peek at the controls manual. Seems I've been blessed with the Classic Commander panel mounted control. Initial glances would indicate that the little gazokka referenced by the #27 would be the origin of my non- "throttle only" condition. Any experience or insight with this?

Again fellas, thanks for the help and introducing me to my new best friends, "Manuel 1, Manuel 2, and Manuel 3":)
 

Bakeys

Seaman
Joined
Jun 14, 2012
Messages
63
Re: Newb - Merc 3.0 overheat issues, throttle control, & trim pump.

Update: Water pump installed. Finished it last night so it hasn't run on the muffs yet. What a mess, I'll have to post some pics if I can figure out how.

On to project two - 'throttle only' fix.
As previously stated, I have a Commander Panel Mounted control that the "throttle only" control does nothing. Suffice it to say that hard starts are the norm. Why wouldn't they be when you can't actuate the throttle?

So I have downloaded the controls manual and there are very specific dis-assembly diagrams and instructions. Which there needs to be, this thing looks like it's going to be tricky, many, many parts.

But what exactly is it that I'm looking for? There are no troubleshooting guides, just a "tear-down" manual of sorts. What exactly is it that fails? This unit, by the way, from what I've read after Googling, is notorious for this.

Any insight, advice, small gnomes that come in the night while I'm sleeping and fix my throttle control, or a youtube video would be tremendous help.

As always, thanks fellas!
 
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