1977 Mercruiser 470 Problems - Please Help

[Syrus54]

Re: 1977 Mercruiser 470 Problems - Please Help

There's no button on the throttle. Just Forward and Back. No other functions.

It has the kill switch thing at the transom. Starter wont make a sound when it's not in Neutral.


But my mail issue right now is the knocking rod or whatever, inside the Oilpan. I have the oilpan off, any idea how I found out WHICH piston has the problem?

 

[Syrus54]

Re: 1977 Mercruiser 470 Problems - Please Help

Here's some pics:

Original

Original

Original

Something inside here is knocking, but WHAT ?

 

[stonyloam]

Re: 1977 Mercruiser 470 Problems - Please Help

Plastigauge will tell you if you have excess clearance on the rod or main journals. You MUST have a throttle only function, maybe the button is missing? Need photo of the control handle.

 

[Syrus54]

Re: 1977 Mercruiser 470 Problems - Please Help

Throttle Pics:

The Black Toggle Switch in the Last pic goes to some lights I just installed.

 

[stonyloam]

Re: 1977 Mercruiser 470 Problems - Please Help

I do believe your throttle only button is missing (broken off). It should be in the center of the control hub.
I believe this is your control, the button is #41 : http://www.mercruiserparts.com/Show...+CONTROL+ASSEMBLY+(PANEL+MOUNT)(36077A1+/+A2) OMG it is apparently still available When you push it in it unlocks the throttle from the gearshift. Should help your starting greatly. Are sure the noise is coming from the lower end. Check the little round plugs at either end of the head. If they rust out, the escaping exhaust can sound like a knock.

 

[Eric 3.7LX Alpha 1]

Re: 1977 Mercruiser 470 Problems - Please Help

I have the same remote. It looks like part of the button is still there. I am almost positive it is just pushed on. The entire handle has an allen set screw at the bottom. Loosen the set srew to remove the entire handle button and all.

Pushing in that button, allows you to "give gas" in neutral. Very important when starting the engine, especially cold. 2-3 pumps closes the choke and primes the engine with fuel, then partial throttle after starting to keep the RPMS up around 1200-1500 or so for a few minutes until it's warm, then click it down to idle.

 

[Syrus54]

Re: 1977 Mercruiser 470 Problems - Please Help

Another good news double-bad news scenario here:

Good: I just took the boat out for the 2nd time. It ran great. Did some tubing, played in the water, it was great.

Bad News: The Couple started smoking, and you can smell burned rubber. NOW, I give it gas, and it barely moves the boat... Are you f*king kidding. The Coupler was the reason it was sitting in a Field for 13 years before I came along. So obviously, the same issue exists. The Couple is heating up SO MUCH, it melts the rubber. Why is this happening???

Double-Bad news: I put in the new solenoid for the TRIM, hit the switch, and it CLICKED (for UP, but not DOWN), but the motor never turned, and the Trim never moved. So I'm half-way home on THAT issue...

 

[stonyloam]

Re: 1977 Mercruiser 470 Problems - Please Help

The coupler will burn out if the engine and outdrive are not aligned correctly. If you are smelling smoke then the metal splined center has separated from the rubber and the coupler is shot. When you replace it (again) you need to align the outdrive with a Mercruiser alignment tool. E-bay about $30. If you did not align the outdrive with the new coupler that is the cause of your current failure.

 

[Syrus54]

Re: 1977 Mercruiser 470 Problems - Please Help

...hooray. :facepalm:

Thanks for your :help:.

 

[stonyloam]

Re: 1977 Mercruiser 470 Problems - Please Help

Yeah the most expensive thing you can get is a free boat.:facepalm: