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1987 Evinrude 40 E40TLCUD Spitting Fuel

B

brewmoody

New member
Motor has a rough idle and will only reach 1700 RPMs. Pulled the air intake box and observed fuel mixture being forced out of top carb. Please see video. Any suggestions on cause and fix?

 
Thank you racerone. I suspected that the reed valves may be the problem, but wasn't entirely sure. Compression is 150 in both cylinders, new spark plugs, carbs cleaned and rebuilt, sync & linkage adjusted, good spark, timing adjusted, new fuel pump. If I restrict air flowing into the top carb at idle, the motor continues to run. If I do likewise with the bottom carb, the motor stalls.

If I find that the reeds are bad and need replacement do you or anyone else have experience or a recommendation on the composite ones sold by Chris Carson Marine Service?

Thanks again!
 
Spoke with Chris Carson and verified that the reed(s) were likely bad. Ordered new from CCMS, installed and water tested. Spitting fuel issue corrected, but still have problem with only 1,700 RPM at WOT. Pulled top spark plug wire and motor will not start. Pulled bottom spark plug wire and motor runs same as with both plug wires connected and achieves 1,700 RPM at WOT. Reconnected both spark plug wires. Swapped wires from power pack to ignition coils and motor will not start. Coils test good. Any suggestions on where to go from here? Thanks in advance.
 
You have a problem with --Bottom carburetor ( high speed jet ) might be plugged.----The jet is in the carburetor bowl.---Bottom crankshaft seal.-----Bottom cylinder sleeve out of position.
 
racerone said:
You have a problem with --Bottom carburetor ( high speed jet ) might be plugged.----The jet is in the carburetor bowl.---Bottom crankshaft seal.-----Bottom cylinder sleeve out of position.
Click to expand...

racerone,

Thanks for the reply. I will check the high speed jet.

How do I check/troubleshoot the bottom crankshaft seal?

Likewise, how do I check/troubleshoot the bottom cylinder sleeve? FYI compression is 150/150 (not sure if this matters).

Thanks!
 
What did you find with the reed valves that you replaced ?-----A leaking crankshaft seal has nothing to do with compression in the cylinder.----Please state clearly which cylinder is not working.----In one post it is the top cylinder and another post it appears bottom cylinder is not working.----If a cylinder sleeve rotated the compression would still show good compression.
 
racerone said:
What did you find with the reed valves that you replaced ?-----A leaking crankshaft seal has nothing to do with compression in the cylinder.----Please state clearly which cylinder is not working.----In one post it is the top cylinder and another post it appears bottom cylinder is not working.----If a cylinder sleeve rotated the compression would still show good compression.
Click to expand...

There was an issue with the top set of reeds. Replacement with the CCMS reeds eliminated the fuel spitting out of the top cylinder and this is the cylinder that is operating correctly.

The bottom cylinder is the one that is not working correctly. Taking the spark plug wire off makes no difference in engine operation.
 
When you cleaned carburetors was there any dirt in them ?----The high speed jet ( orifice plug ) is screwed horizontally into the carburetor bowl.---Did you remove it , and confirm it is clean ?
 
The carbs were cleaned and rebuilt by a local marine repair shop. They said that they didn't take the jets out because the slot was stripped, so they cleaned it with the orifice in place.
 
If a shop had to do your ultra simple carburetors then have them sort out why your motor is not performing.---I believe it will be simple.----Spark at the right time.----Compression.----Correct amount of fuel.----Crankcase compression. -----Running with VRO in service ?----Running with another type fuel pump ?---Does spark jump a gap of 7/16" or more , yes or no ?----The term " good spark " means nothing here.
 
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