Honda 75 Runs very rough when first started then less rough

My outboard repair man tells me that it's normal for any Honda:

1. To have to set my throttle arm to 1/2 full speed when starting any honda outboard to get enough gas into the carbs, which I have to do?
2. Then when it does start it runs like it's running on 1-2 cylinders for 3-4 minutes before it smooths out some. It coughs and sputters like it's not getting the right amount of air or gas. He also says this is also normal?
3. It can be running at "my" full throttle 5000k max and I can still hear it coughing although it never dies completely. I've never had a Honda before but I can't imagine this is normal.

The engine (1976) only has about 75 hours of operation time on it. I've had the carbs removed and cleaned twice and I use only ethylene free gas. Any suggestions would be appreciated. Again many thanks

I partially agree with him.

Yes, you do have to advance the throttle a lot and choke the engine to start. Be sure to squeeze the fuel bulb until it is hard.

Yes, it will sneeze and cough for a couple of minutes, but it should not for 3 or 4 minutes.

Once the engine gets to temperature, it normally should smooth out.

Sounds like you may still have some carb issues or you could have a valve or cylinder issue.

Whomever cleaned the carburetors should have done a compression test, before they even touched the carbs.

Make sure the engine is coming to temperature. The thermostat should open somewhere around 180 degrees F. If it is not getting to temperature, then most likely the thermostat is stuck open.

Make sure you are using NGK DR7EA spark plugs (no substitutes).

Make sure your fuel has not water in it. Water can cause coughing and sputtering.

Perform a cylinder drop test to see if you can isolate which cylinder may be giving you trouble. Pull the spark plug wires off the plugs one at a time as the motor is running using insulated pliers. The engine running should change (bogg down some) as you pull each wire. If there is no change, then that cylinder has an issue. Hold that plug wire close to the spark plug and you should hear the arcing of the spark. If you do, then most likely, it is not a spark problem. If the compression is good, then the most likely next location of the problem is the carb.

There are several transition passages in the carbs. If you do not get all of these clean;if you do not get the idle jets clean (or replaced); and you do not set the idle mixture correctly (1 7/8 turns out), the engine is going to cough and/or sneeze.

The arrow on the dashpot (part #20) http://www.boats.net/parts/search/Honda/Outboard%20Engine/2002/BF75A2%20LRTA%20/THROTTLE%20CAM/parts.html should be pointing towards the carburetors.

You had questions on another thread about setting your full throttle. Do check those linkages for full throttle, but if all the carbs and cylinders are not working correctly, then you will never get full throttle.

Other possibilites....

If this boat is new to you, you may have too large of a pitch of prop.

The oil may be too high. Should be about 1/4 inch below the top mark.

You may not be trimming the motor up to the proper angle for efficient operation.

There is a start....

Mike

Mike you've given me several things to check and I need to get started. I can say that I checked to prop and it is perfect for the motor. I'm going to start by checking my oil level before I check other areas.

Thanks again. I'm sure this will help me solve the issues. I'll get bsck to you if I discover more questions.