1984 Mercruiser 470 Starting Issue

[g3nu1n31]

Hey everyone, I am having issues with my engine not starting and am hoping someone here can help me with it. Here is the back story:

I bought this boat a few years ago non starting. Was told it just needed a starter to I bought a new starter for it and after a few years I was able to get it in and the boat to turn over. Once that was done, I noticed that the previous owner JB Welded the adjustment screws and the carb was leaking gas so I bought a newly rebuilt carb from a very reputable company. I am finally able to get the boat to start but only when it is with full throttle. I can not get it to start or run on idle. the engine will die when I get to 3/4 throttle. When it full throttle it runs strong.

I have had the timing done, new spark plugs, tested spark, and compression was good. I also tried using starting fluid on idle and it still wont start with that either. I can't for the life of me figure out why it wont start or run on idle. Does anyone have any Idea as to why this might be? Any help would be amazing. Thank you very much.

 

[cyclops222]

Why do people buy a not starting / running boat ? They would not buy a car like that.

 

[Scott Danforth]

your 470 has points ignition.

you will have to service the points, set dwell with a dwell meter, then set timing.

regarding the carb, my guess it needs to be gone thru.

 

[Scott06]

Why do people buy a not starting / running boat ? They would not buy a car like that.

because if you can fix it you can save some money. Have bought both project cars and boats over the years, and houses too... but you have to enjoy the project and have to have the skills to get it done.

My current boat I bought with a known cracked engine block. repowered and saved a bunch of money, on our 9th summer using it now. For us at that time of our life it was the difference between affording a new to us boat or not.

 

[g3nu1n31]

I bought it as a project to learn and have something to do. It was extremely cheap and I thought worth it. Still is if I can get it to start and run at idle.

The carb is a newly rebuilt carb from reputable company. But I can disassemble and check everything if needed. As for the points, would it still run at 3/4 throttle if they needed to be cleaned and set?

 

[Scott06]

I bought it as a project to learn and have something to do. It was extremely cheap and I thought worth it. Still is if I can get it to start and run at idle.

The carb is a newly rebuilt carb from reputable company. But I can disassemble and check everything if needed. As for the points, would it still run at 3/4 throttle if they needed to be cleaned and set?

If it has been sitting any amount of time clean and set dwell on the points.

I would do the points service see what that gets you then go into the carb if there are still issues. This assumes you set the idle mixture and idle speed or at least roughed them in.

Have you done a compression test