1986 Evinrude E40elcde Bottom Cyl Dies part time

[rlray42]

Last week I kitted both the carbs. (seems like I have a carb problem every year) Even replaced welch plugs this time, cleaned out every passage that I could find. Compression 149 both cyl. Reed 'appear' to be intact & not stuck. HOT spark both cyl. Jumps a good 3/4 inch. Replaced all fuel lines with clear fuel hoses so I can see the gas flowing. Started it up, expecting a smooth run. Drop test on bottom cyl showed not hitting. Pulled carbs again.. Raised float on bottom carb a bit (Lowered upside down) -- Back together, ran great for a good little bit.. While running, I dropped the tilt down to normal position (like sitting 'in the hole') & the bottom cyl 'died' !! (Still had great spark.) -- The needle seat that came with the kits would not screw all the way in, so I used the old seat (after inspection) and used the NEW needle.. Could 'mixing' the parts be the problem?? Any other thoughts?? Thanks

 

[rlray42]

The carbs are 36901

 

[racerone]

Review carburetor part #---Usually 6 numbers used.----Test run with a timing light to see if you are loosing spark to # 2 cylinder.

 

[Sea Rider]

If that engine has indiividual Ignition Coils for each plug, that could be the culprit. Heats up shorts and cylinder doesn't have spark till cools down again to start the whole fluctuating temp failure,

Happy boating

 

[rlray42]

CORRECTION: The carbs are 395790 - I posted the number of the KITS that I used.. Sorry again..

 

[racerone]

With engine running squirt some fuel into the top carburetor.---What happens.----Now squirt some fuel into bottom carburetor and what happens then ??-----What happens when you push the key in with motor running ?

 

[rlray42]

Racerone -Just now tried your suggestion.

Motor sitting in the bright sunlight. (I usually don't work on it if it's not in the shade.)

Saw small drops of fuel spitting back out of the top carb. ??
- Fuel squirted in the top carb = sputtered the picked up speed.
- Fuel squirted in the bottom carb= not much change.. maybe more fuel spray out the top carb.??

Thanks...

 

[rlray42]

With engine running squirt some fuel into the top carburetor.---What happens.----Now squirt some fuel into bottom carburetor and what happens then ??-----What happens when you push the key in with motor running ?

Pushing key in: If pushed briefly it speeds up.. hold too long floods out..

Motor sitting in the bright sunlight. (I usually don't work on it if it's not in the shade.)

Saw small drops of fuel spitting back out of the top carb. ??
- Fuel squirted in the top carb = sputtered the picked up speed.
- Fuel squirted in the bottom carb= not much change.. maybe more fuel spray out the top carb.??

Thanks...

 

[rlray42]

Continuing to dig into this problem. I read some cases where the powerpack can fail & fire both cyl at the same time. I rigged up a little test and confirm this is NOT my problem. -- I have on order two more NEW float needle & seat sets + a reed (petal) & manifold gasket & will try those in turn to see if either helps.. Thanks, folks.

 

[rlray42]

If that engine has indiividual Ignition Coils for each plug, that could be the culprit. Heats up shorts and cylinder doesn't have spark till cools down again to start the whole fluctuating temp failure,

Happy boating

I guess my title was misleading. It is dead from a cold start now after my adjusting float settings.. My next step is back in the carbs + replace reed petals.. can't find the whole assembly..

 

[rlray42]

Last week I kitted both the carbs. (seems like I have a carb problem every year) Even replaced welch plugs this time, cleaned out every passage that I could find. Compression 149 both cyl. Reed 'appear' to be intact & not stuck. HOT spark both cyl. Jumps a good 3/4 inch. Replaced all fuel lines with clear fuel hoses so I can see the gas flowing. Started it up, expecting a smooth run. Drop test on bottom cyl showed not hitting. Pulled carbs again.. Raised float on bottom carb a bit (Lowered upside down) -- Back together, ran great for a good little bit.. While running, I dropped the tilt down to normal position (like sitting 'in the hole') & the bottom cyl 'died' !! (Still had great spark.) -- The needle seat that came with the kits would not screw all the way in, so I used the old seat (after inspection) and used the NEW needle.. Could 'mixing' the parts be the problem?? Any other thoughts?? Thanks

** SOLVED (I Hope) ** I think using different needle & seat WAS the main problem. (sticking?) -- I ordered a 2nd set of OMC OEM needle & seat + one reed petal. (I was confused by the parts diagram, thinking my motor only had 1 leaf plate assembly.) Actually, when I got in there, there are 2 leaf plate assemblies, each with 2 reed petal plates. -- After getting the manifold plate off I used a bright LED flashlight & could see a little gap in one of the reeds for the troublesome carb. After replacing that, I put it all back together & dug out my trusty Climer Manual and carefully followed the 'Link & Sync' instructions. Took a little tinkering with the idle adjustment but running great again.. I hope this helps someone else.

 

[fireman57]

Glad it worked and thanks for posting the fix. Stick around and help the next guy now that you have knowledge to share.