'87 Evinrude 140 Sometimes stalls in gear?

Question

Hey guys I have an '87 Evinrude VRO 140hp V4 outboard (I call it the tank) on my boat. I have been having clogging issues with the internal fuel tank so I switched over to some 6 gallon ones which I treat with Startron Fuel Additive.

Firstly, even if the engine is hot, it usually will not turn on unless I give it 1/3 or more throttle.

Cold starts, usually not a problem, starts after 2 or 3 seconds of cranking with 1/3 throttle and choke engaged then I warm it up at 2500 rpm for 30 seconds

Second, it stalls out sometimes in gear at low RPM. It idles fine, around 1200 RPM. However, when I have it at low throttle in gear it runs at around 700rpm and sometimes stalls out. It stalls the most when in reverse and sometimes when shifting. (Lately I have had to shift fast and give it a lot of reverse throttle to prevent stall) After it stalls, it can be fairly difficult to get the engine started again and at times requires almost full throttle to turn back on. I would like to fix this

Answer 1

700 to 800 is the correct idle RPM in gear.

Carb float valve needles and seats start to wear out, fuel leaks past;  you get a rich mixture, and flooding at low RPM, makes for difficult warm starts and problems idling.  

The hi-idle throttle mostly just advances the spark -- the carb throttles don't even start to open until about the last 50% of travel.  Fact that this makes warm start possible confirms the diagnosis.

Solution:  rebuild carbs, install new kits.  Piece of cake for a do-it-yourselfer with basic tools and a good service manual.

Get parts and manual at http://iboats.com or http://www.ishopmarine.com

problem with running carb cleaner through a two-stroke is, any solvent strong enough to clean the varnish off a carb will clean the lubricating oil right off the cylinder walls.

If you wouldn't run your engine without oil, don't run it on carb cleaner.

Only one way to properly clean a carburetor: remove, disassemble, soak overnight in carb cleaner (I use B-12), blow through passages with compressed air (or aerosol carb cleaner)

Answer 2

My dad used to have a older evinrude around the 87' range, and he used to have some similar problems as well.

I would check the spark plugs and fuel filter, and change them if you haven't in awhile. The mixture of gas/oil for 2 cycle engines seems to add more build up on spark plug terminals causing them not to fire efficiently after time. There could also possibly be blockage in your fuel lines, never know about older engines and components.

Otherwise if that doesn't do the trick, it could possibly be a carberator problem. The wrong air/fuel mixture will cause it to flood, not fire completely, or even at all.

I don't know a whole lot about outboard engines, but every internal combustion engine needs, spark/ignition (with the correct timing), the correct air/fuel mixture, and adequete compression within the cylinders.

You could always start by spraying some carb cleaner in your carb, and see if that does anything since you were mentioning blockage problems with other components.

Answer 3

Texas is right on but you might also have a weak charge coil for the ignition. When the rpm drops so would the ignition. So put a timing light on it and see if the ig drops before the motor dies or will the ig run right down to zero.

Answer 4

You have issues with thash in the carbs from the other tank clean the carbs>