1984 150hp Evinrude rough idle dies on acceleration

I just bought a new to me boat with a 84 150hp V6 3 Carb Evinrude. Don't know a lot about past history. Bought it from a dealer on Ebay about 175 miles away. Got a good enough deal on it and the dealer said it runs great and was stored properly. Got it home and it doesn't run great. It snorts and coughs at idle and when accelerating I need to hold the choke down or it will die. Once up to speed if I hold the choke down again it will jump about 700rpm and smoothen out some, not that it runs bad once up to speed, but its just better with the choke in.

I tried seafoam in the carbs and letting it sit and starting it up to blow out the carbon and any old residue. It seemed to help when on the muffs. Idled nice and smooth and started real nice, even after sitting a couple of days, touch the starter and she would pure like a kitten right of the bat.

I get it into the water 2 days later and its still the same old acceleration problem and rough idle and hard starting problem.

Am I going to have to clean the carbs and put in a kit? I called the dealer and they wanted around $400 to do this. I am mechanical, cars, small engines and such, just haven't had to do too much with boats before. I don't have a manual to help me. Is this something I could do myself with some information from others? I don't know what the jets have to set to, or which ones are the low and high speed.

Thanks for any help you can give.

Re: 1984 150hp Evinrude rough idle dies on acceleration

Welcome aboard mnboater!

If the dealer gave you a line about running good and it don't......think I'd be on someones desk jumping up and down.....just my opinion.

But yes, sounds like you need a carb cleaning and over haul. The carbs are simple enough. If you have a local library, look for a generic manual like Seloc or Clymers. They usually cover carb overhaul.

If you clean them, soak them in carb cleaner first after diassembly. Follow up with carb cleaner in a spray can shooting it through the carb passages. Follow this up with compressed air.

While your there, replace any fuel lines that have become hard and are not plyable anymore. These can lose their grip on connections and leak air.

Is the VRO pump still connected to the oil supply? And does the pump have any wires coming from it?

Do you have any maint history on the engine like the last time the water pump impeller was changed out or t-stats?

Re: 1984 150hp Evinrude rough idle dies on acceleration

Thanks for the reply and the welcome obj.

About the delaer - Wth the price of gas, I can buy the parts and fix it myself a lot cheaper than bringing it to the dealer to fix. I am talking with them right now about a reimbursement for my expenses to bring the boat back to them for them to fix. We will see what happens there. But thats why I am doing the planning for doing the work myself if that falls through. If I can't get the reimbursement for mileage, the least they can do is send me the parts.

I checked all the fuel lines and they are pliable and appear to be in good shape. dont bulb stays hard, so I don't think there is any leaking in the lines.

If I get a generic manual that is not specifically for that motor, will the jet settings be the same? carbs Is it a basic setting for carb carbs or is it unique to each carbs?

When people talk about syncing the carbs, what is that?

The motor does not have VRO. Its premix.

thanks

Re: 1984 150hp Evinrude rough idle dies on acceleration

not sure but believe your carb jets are fixed and not adjustable. link and sinc, is a step by step adjustment that sinconizes the carbs to the electrical timing, so the perform together. with proper advance. just looked at aftermarket manual, and it's lousy for this adjustment. do yourself a favor, and get the OEM engine specific manual.

just for grins, check your compression and post results. all plugs out,in forward throttle wide open, will have to jump solenoid to turn over, as neutral switch will disable key.