40hp Evinrude dies during idle *Video*

[Stryker23]

hey guys,

I bought a very low hour Bass Tracker Tournament TX17 with a 1992 Evinrude 40hp outboard. The motor will start up and begin to idle like normal, it will run for about 30sec and then just shut off. It struggles to restart unless I press in the key to choke it, it will restart up. The motor revs up nice an smoothly once in gear. One thing i noticed is that when idling if i press in the chock every few seconds it will idle forever, as soon as I stop randomly pressing in the choke it will eventually die. I have disassembled both carbs and throughly cleaned them, i pull out both jets and made sure they were clear. The carbs were not dirty at all to begin with, the floats move freely and seem to be adjusted correctly from what i have researched online. The spark plugs are new. The fuel filter is newish and not clogged in anyway. The primer bulb and the fuel line running to it were replaced by the previous owner. Please watch the video below so you can see what i mean by it eventually "shuts off". I know this is usually fuel related, but just need a little advice of what to check next. Thanks!

http://vid33.photobucket.com/albums/d75/atvkid4eva/IMG_4701_zpsbii8iy86.mp4

 

[Bosunsmate]

Is it warming up?
You also need to move the telltale outlet to the top of the motor or airbubbles can form a pocket of air up there and she will overheat.
Did you blow carb cleaner down the little idle passages and check it came out somewhere in full volume? As those little passages are normally what block up and not the jets as such

 

[Bosunsmate]

Also hows it run on the water? And do you have to reprime it to restart or only use the choke?

 

[Stryker23]

Yep the issue is exactly the same once the motor is warmed up. I haven't had the motor in the water yet, only using the garden hose. And yes I sprayed carb cleaner and air down every little passage within to make sure all were completely clear and came out the other side.

All I have to do to restart it is to just press the key in one time to choke it and turn the key and then you get what you see in the video.

 

[oldboat1]

suggestion or two: run the motor deep in a large tub of water or in the lake before doing additional analysis. Make sure it pumps water, and see if it operates differently with back pressure. See if it stalls going in and out of gear at idle. If it needs to be choked to remain running, a clogged jet is usually the issue. (If squeezing the bulb keeps it running, it's usually a fuel pump issue.) To clean a carb it needs to be removed from the engine and disassembled -- usually a kit installed at that point. On disassembly it should be soaked and then the jets and air passages blown out with compressed air or carb cleaner. Remove the core plug/expansion plug at the carb top (with a kit replacement plug in hand), and clean out the low speed passages along with the l.s. jet. It sounds to me like there is still a carb issue.

 

[Stryker23]

oldboat- yes, i will take the motor to the lake and see how it runs. The primer ball seems to be hard when the engine is running and even if i keep squeezing it will still eventually die. The only way i've gotten it to continue to idle is by pressing the choke in and out every 10-15 seconds or so.

I did disassemble the carbs, the only jets i pulled and cleaned were the one in the float bowl and the one right above butterfly in the top center of the carb. I didnt remove any of the plugs, but are there additional jets underneath there? If you can guide me to where the other jets are, i will be sure to pull and clean them. I did clean ever passage i could access with carb cleaner and compressed air.

 

[oldboat1]

Work from a parts blow up: evinrude.com, or similar, and drill down to your model.

 

[Stryker23]

i put the motor in a large garbage can filled with water. It seems to idle worse and would barely stay running. Seems to run much better on the Muffs than when submerged.

 

[oldboat1]

yeah, likely reason for that is the back pressure. (Check to be sure it's pumping water, and monitor engine temp. Best to keep a hose running in the barrel to refresh the water and cool it down.) If you have carb issues, the problem is likely to show up with back pressure, at idle, going in and out of gear. Object is to get the motor running smoothly at idle, with no stumbling when you slip it in gear. You are after slow running as a measure of motor condition/operation.

 

[racerone]

Has a compression test been done ????

 

[Stryker23]

i have not done a compression test yet. i will though. I am also going to disassemble the carbs and dip them so i can eliminate them having and clogged ports.

 

[oldboat1]

uh -- got to soak a carb after disassembling (metal parts only), then blow out ALL the openings. Get a kit and take off the compression fitting on the top (idle passages). I use a tiny wire to get into all passages. Some guys here use PineSol (HighTrim suggests that). I use lacquer thinner (but it's nasty stuff).