1987 40hp evinrude vro (oil deleted) carb issue?

Shwinkyyy

Seaman
Joined
Jul 8, 2017
Messages
70
Just bought this vessel a couple days ago.
Just put it in the water to run a test, in the beginning it started fine but couldn't get any pickup like it was starving for fuel.
Come back to dock, pulled and cleaned carbs out, then reinstalled. Now motor doesn't want to idle, had to many issues at idle to try to run throttle open. So unfortunately I don't know how the high speed is acting after cleaning.

1987 40 hp evinrude vro (oil injection deleted)
MODEL #: E40TLCUD
Serial#: C1464143

Compression test:
130 top
125 bottom

No link and sync, I have no idea how to do this but my mechanic buddy is already reading up on it to try.

Has good spark both cylinders.

Now with inspection of carbs by buddy noticed some small damage on the casing of carb right at the stem of the butterfly valves, and it seems as if the previous owner was doing some tinkering with them (wierd dremel marks etc.) We are coming to the conclusion that it needs new carbs possibly. Does this sound accurate? And if so where would I source the carbs at? Can I trust ebay?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
37,793
Remove carburetor bowls.-----Are they clean or is there green " varnish in them ?----Did you remove high speed jets ( orifice plug ) to make sure they are clean?-----Is the fuel pump mounted directly to the side of the top cylinder ?
 

Crosbyman

Vice Admiral
Joined
Nov 5, 2006
Messages
5,430
very conventioanl carb ...idling requires fuel to up the side and into the top chamber under the dime size plug . the throtlle plate being closed at idle will allow crankcase vacum to suck the fuel up the side of the carb into the idle chamber and... into the crankcase


the side channel in the upper section of the carb is very small and must be 100% clean...of any accumulated crud same for small " drip holes" under the de top plug . the LS orifice passage must be cleaned out etc....soaking won't always do it .

1718023845679.png
 

Shwinkyyy

Seaman
Joined
Jul 8, 2017
Messages
70
Ok thank you so much for the feedback, I am going to mess with them some more today. I will make sure to get pictures and post them here so maybe you guys can see something I cant.
 

Crosbyman

Vice Admiral
Joined
Nov 5, 2006
Messages
5,430
shoot some carb cleaner up the upper section side hole to the drip chamber while you put your finger on the LS orifice #29.

blow out everything with air compressor incl bottom section and all paths and HS orifice #19


carb cleaner should drip out the 3 small holes if you look closely... if not they are plugged up in the chamber under the dime size plug.

see utubes on proper carb cleaning
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
13,442
A lot of Idle and Off Idle Problems are because of Gum/Varnish/Dirt under #5, soaking just lets more of the above settle in there. The Disk has to be removed, the chamber cleaned, and a new disk installed.
 

Shwinkyyy

Seaman
Joined
Jul 8, 2017
Messages
70
So just for starters this is the chip in the housing my mechanic buddy is worried about, right next to where the spring is.
 

Attachments

  • 17180549967542029595787664154949.jpg
    17180549967542029595787664154949.jpg
    2.6 MB · Views: 8

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
13,442
Get a couple of Carb Rebuild Kits, and clean them, Properly, and then rebuild them. taking the time to ensure the Float is set right, and that all needed Gaskets are used
As for the chip in the carb body on the Throttle Shaft, while you have it off spray some carb cleaner on the Shaft and see how much seeps through. I suspect there is No Problem there
 

Shwinkyyy

Seaman
Joined
Jul 8, 2017
Messages
70
Ok so after doing some of the above mentioned stuff this is where I ended up. She is idling again but she does have a little lean sneeze. I'm thinking of dropping her in the water again to see if I can get her wide open now and see how it reacts.

Just cleaned her up again, and did a small adjustment on the enrichment screw.
 

Attachments

  • 20240610_201046.mp4
    40.9 MB · Views: 0

Shwinkyyy

Seaman
Joined
Jul 8, 2017
Messages
70
Just another clip, I'm trying to be thorough so you guys can really see it.
 

Attachments

  • 20240610_201731_1.mp4
    38 MB · Views: 0

Shwinkyyy

Seaman
Joined
Jul 8, 2017
Messages
70
Just took a test on the water, idle works great now. Works in gear at slow speed, as soon as go to throttle up she bogs down and starts to stall out. I'm starting to think maybe I need a new fuel pump?
 

saltchuckmatt

Commander
Joined
Jul 19, 2019
Messages
2,624
Sounds good really. Sneeze but your idle is low I believe.....set the idle in the boat running. After a zip around the lake, she probably will clear up because that's how they were designed.

I forgot to send this...it was made several days ago.
 

saltchuckmatt

Commander
Joined
Jul 19, 2019
Messages
2,624
Try pumping the primer ball when it starts to bog out....if it returns to normal then your guess is correct.
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
13,442
Looking at the Parts Book for an 87 40hp, you cannot adjust the Idle Mix on the Carbs, as they have a Fixed Jet.
So either your engine in an 87, or the Carbs are from something else...
With a Fixed Jet Carb, any Lean Condition would imply Air Leaks, Low Fuel Level, Restrictions in the Fuel System, lack of Fuel to the Carbs. Improper Link and Sync, won't cause Sneezing, but can cause Hesitation and Bogging
 

Shwinkyyy

Seaman
Joined
Jul 8, 2017
Messages
70
Looking at the Parts Book for an 87 40hp, you cannot adjust the Idle Mix on the Carbs, as they have a Fixed Jet.
So either your engine in an 87, or the Carbs are from something else...
With a Fixed Jet Carb, any Lean Condition would imply Air Leaks, Low Fuel Level, Restrictions in the Fuel System, lack of Fuel to the Carbs. Improper Link and Sync, won't cause Sneezing, but can cause Hesitation and Bogging
When I made the adjustment it wasn't on carbs, it was on the primer solenoid.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
37,793
The primer VALVE is not used to adjust mixture.---I think you need to revisit carburetor cleaning.-----Or consider the simple task of removing cylinder head to inspect in there.-----Compression values are LOW on your motor.
 

Shwinkyyy

Seaman
Joined
Jul 8, 2017
Messages
70
The primer VALVE is not used to adjust mixture.---I think you need to revisit carburetor cleaning.-----Or consider the simple task of removing cylinder head to inspect in there.-----Compression values are LOW on your motor.
Cleaned carbs again, new fuel pump, pulled and cleaned the manifold (something black shot out of it when cleaned) and I'm back to square one again, rough idle doesn't want to stay running, and won't throttle up. When I hold the key in for choke she will open up just fine. I guess it's a rebuild or just new carbs. At this point I might as well just spend the $8,000 and repower.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
37,793
You will be delighted with a new 4 stroke.-----Computor does all the thinking for you.------Trouble free boating with a 4 stroke until there is trouble.
 
Top