Boat wont move under load, Help!

Hi guys,
First time boat owner, first time posting. Thanks for any help.

Heres the story:
Bought an old '67 16ft "Esquire" (according to pink slip), with a Mercruiser 4cyl in it.

Took it for a test spin before buying, everything seemed to work fine, moved nicely, engine sounded good.

Trailered it home 100 miles. Took it out 2 days later, and when I tried to accelerate, boat would not move forward or reverse at all. Not even a hint of movement.

Pulled the boat back out of the water, tried to see if prop would spin, and it does spin out of the water.

I have not had the chance to take out boat again and test "alignment marks" test and i do not have a bucket big enough to test, but under no load running for about a minute, the alignment marks were still in sync.

Out of the water, while in gear, I can turn the prop freely in both directions (pretty easily) with a clicking sound coming from the prop area.

I'm obviously new to boats, but the throttle linkage appears to be engaging and disengaging, but I could be wrong.

I've read it could be spun prop, coupler, dog gear?

I feel as if I should get a new hub kit and install it, but before I do that, how do I make sure it is not the coupler, etc?

Thanks a mil
-Chris

Re: Boat wont move under load, Help!

You may have your shift in neutral. Send us pic of the throttle/shift control, or describe it it to us.

Re: Boat wont move under load, Help!

It engages into forward, I can tell from the test drive I had of it, and I can feel and see it engage and pull the throttle spring afterward. When I start it out of the water and put it into forward and gas it a little, the prop spins at speed. Doesn't that mean its in forward, or could there still be slack in the shifting linkage?

Being in forward, it spins very easily in both directions with engine off.

Re: Boat wont move under load, Help!

Pulled the boat back out of the water, tried to see if prop would spin, and it does spin out of the water.

Click to expand...

Was you in neutral or in gear?
Pull the throttle lever back to neutral. Does the button on the center of the control pop back out? It should. Then put it in forward and see if the prop still spins (CCW should lock, CW will ratchet).

EDIT: I was typing while you were posting.

Does your engine overheat?

Re: Boat wont move under load, Help!

When in gear and engine off you should only be able to turn the prop one way.

Re: Boat wont move under load, Help!

Don S said:

Was you in neutral or in gear?


Does your engine overheat?

Click to expand...

When I pulled the boat out of the water, I put it into forward and accelerated and the prop spun increasingly faster with acceleration.

The accelerator lever button stays popped out while shifting, and when i depress the button, it simply moves the lever without moving the linkage. So it has been moving the linkage the whole time.

As for overheating, i'm not quite sure, the cheapo gauge said it was fine, but it may very well be broken, since other gauges are broken too. Could this be caused by overheating?

Thanks for the help

Re: Boat wont move under load, Help!

Could this be caused by overheating?

Click to expand...

No, but if the coupler splines were stripped out, the drive wouldn't be turning, therefor the raw water pump in the drive wouldn't be pumping or cooling your engine.

When the throttle lever is in forward, can you turn the prop CCW by hand. If you can turn it by hand, is there resistance? Can you turn the prop using one finger?

Don't forget, we can't do this ourselves and the differences can mean a lot.

Re: Boat wont move under load, Help!

Don S said:

When the throttle lever is in forward, can you turn the prop CCW by hand. If you can turn it by hand, is there resistance? Can you turn the prop using one finger?

Click to expand...

With the throttle in forward, I can easily spin the prop both directions with one finger

Re: Boat wont move under load, Help!

280zxt said:

With the throttle in forward, I can easily spin the prop both directions with one finger

Click to expand...

Then you are still in neutral for some reason. The prop may pickup some speed, but that could just be due to the gears spinning and the friction from the gear lube.

Disconnect the lower shift cable at the shift plate on the engine, then start the engine (on muffs) and push and pull the shift cable and see if it shifts the drive. You should be able to hear it.

Re: Boat wont move under load, Help!

Don S said:

Then you are still in neutral for some reason. The prop may pickup some speed, but that could just be due to the gears spinning and the friction from the gear lube.

Disconnect the lower shift cable at the shift plate on the engine, then start the engine (on muffs) and push and pull the shift cable and see if it shifts the drive. You should be able to hear it.

Click to expand...

Ok, thanks, I will try that.

One difference I've noticed - When the throttle is in neutral, I can spin the prop easily with no resistance in both directions. BUT when I put the throttle into Forward, I can spin the prop easily forward, but when I spin CCW there is an audible CLICKING and just a slight bit of resistance. What does that mean?

Re: Boat wont move under load, Help!

Before we go too far with this, What engine do you have? Being a 67, it's hard to say what drive you have, or what's wrong.

Re: Boat wont move under load, Help!

Don S said:

Before we go too far with this, What engine do you have? Being a 67, it's hard to say what drive you have, or what's wrong.

Click to expand...

Not quite sure, its a 4cyl. Engine runs pretty strong, as I said, I took her for a spin a week on sunday, then this problem developed the next time I had her in the water

Re: Boat wont move under load, Help!

Can you post some pictures of the engine & drive? Seems like the drive isn't engaging into gear completely. Maybe the cable is mis adjusted or loose somewhere. Did you try what Don suggested with shifting it manually by moving the cables at the engine?

Re: Boat wont move under load, Help!

See if you can find a metal Mercruiser tag attached to the block. They are in different locations depending on the engine. The engine serial number is on there, It can be used to look up what you have.

If you can find it post the numbers.

Re: Boat wont move under load, Help!



here's a couple pics I snapped of the linkage and the back end

i found some stamping on the engine block: "3849449" and "CON 2" and "G146"
stamping on drive part (not sure what its called that connects the crank to the outdrive) "S6C" and "MC-20-55538" plus "5-11-1989"

i am going to try the suggestion about the linkage cable now. thanks

Re: Boat wont move under load, Help!

A picture of the whole engine, not just one small part of it.

Re: Boat wont move under load, Help!

From looking up the stamp numbers, I'm guessing the engine is 153 ci (2.5 L) Mercruiser / OMC, Inline 4 Cyl. Or a 151 ci.

After checking the lower shift cable like you suggested, I can now push it further in and when in forward, the prop no longer spins both ways easily. It spins forward with a slight clicking and it does not spin CCW at all.

What is the proper way to calibrate these cables?

Thanks

Re: Boat wont move under load, Help!

I'm trying to adjust the lower cable, and i can get it to work when not bolted to the shift plate, but any which way i try - once connected to the shift plate, the brass barrel is too far away from the connecting bolt. Even if I drop the adjuster to the bottom of the slide. How can I fix this?

Re: Boat wont move under load, Help!

Sorry, got confused by the 6 inch measurement. I've got it now to where it won't slip CCW while in forward, so I'm going to take it out to test.

Re: Boat wont move under load, Help!

It went well in forward. Reverse wont go.

N00b question of the week - how do I know if I have reverse or not? Is that standard?