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Can not get this thing to idle!

Progator135

Progator135

Regular Contributor
1985 E50BELCO
I just rebuilt it and even before that I was having idle issues. It is spitting fuel from the Idle Bleed Orifices (Not from carb Throat at all) and I have to crack the carbs ever so slightly with cam adjustment to get to stay Idling. If I adjust it back and close them completely it dies out unless the timing advance is completely maxed out - Wrong on every level.
Things I have done/checked:

1. Got new(used) carbs that have much less slop in the butterfly shafts; (Thanks scalhoun) rebuilt with all new gaskets & parts, pulled core plugs and ran wire through idle ports - all is clean and new and as perfect as can be. Float level was set where the non-hinged end was maybe 1/64" higher than level. Needle valve was sealing good when Id blow in intake and flip carb upside down.
2. Compression test - Both about 149.
3. Reed valves pulled cleaned checked - I had about 8-10 psi difference in the cylinders compression at first - thought that may be the culprit. Actually took my old reed valves (the block I bought came with reed valves - they looked fine so I used them) and did a thorough cleaning and inspection and they are in perfect shape. all flat and sealing good. Changed them out and reinstalled with a new gasket from rebuild kit that I didnt use during rebuild. This evened out my compression thankfully but no help on idle.
4. Spark test - both jumping 7/16 gap like a champ.(with new storebought tester) No issue there. Also did cylinder drop test and motor reacted as expected on each cylinder test.
5. Checked fuel lines/hoses. All new, clamped or zip tied tight. No leaks or air being drawn in. Even little tubes from primer are new.
Question: Turned over motor with fuel line from pump disconnected to check fuel delivery - how much should be shooting from pump while turning over - I had a decent trickle but It wasnt shooting across the yard either - whats the norm for this? I rebuilt the fuel pump last year but who knows. (I remember the new circular snap in valves were much stiffer than the old ones, I had some concern with this when I rebuilt it)
6. Squeezed primer bulb while running/stumbling/coughing/spitting - no change at all...
7. Pulled flywheel and made sure it was on correctly and hadnt slipped the key. All is good.
8. Checked all wiring and plug leads for any stray voltage shorting to ground or any other abnormality. All is good as far as I can tell.
9. Brand new plugs gapped to .030

Well thats my story...any Ideas? Im gettin fed up.
 
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For your information only.-----The reed valves have nothing to do with compression in the cylinder !!------Operating the bulb made no difference which indicates fuel pump is good.---------You need to look at the carburetion and synchronizing ignition with throttle advance on this motor.-------What sealer did you use on the crankcase halves and are you sure that the 2 halves are tightly bolted together .---Bearings properly seated on the dowels ?---This is a precision metal to metal joint.-----Too thick of a sealer will cause crankcase compression problems !
 
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Yeah I see your point on the reed valves - thats on the opposite of the piston. Sometimes you grasp for an answer no matter how a** backwards it is..
I used a very thin layer of Loctite 518 red gel sealant and torqued per the specs in the manual. I knew too much would cause shimming so I was careful not to have that happen.
"You need to look at the carburetion and synchronizing ignition with throttle advance on this motor"
I spent the better part of my day doing that yesterday - What more can I do that I havent already done - I understand the Link & Sync Process pretty well and If I get everything lined up with the marks where they are supposed to be It will not stay idling even with the Timing Advance (Idle adjustment screw) maxed out. Something is way off. What causes the fuel to spit out if the idle orifices so bad?

Now that being said - My fuel mixture is still pretty oily from the first tank of 100:1 for the break in. It still should Idle shouldnt it?- maybe a little rougher just a bit smoky - I think Im going to dump it and go ahead and mix a tank of 50:1 and see if that helps. I wouldnt think that would affect it that bad. But Im running out of options.
 
?????----What ?--------Where did you get this idea of running 100:1 for break in ??----That is not near enuff oil.---------It should be 25:1 for break in !!!!
 
racerone said:
?????----What ?--------Where did you get this idea of running 100:1 for break in ??----That is not near enuff oil.---------It should be 25:1 for break in !!!!
Click to expand...

I'm sorry...thats what I meant....doubled my oil. My coffee hasn't kicked in apparently
 
1985 E50BELCO <---- This 1985 engine comes in two different lengths, a 15" shaft model and a 20" shaft model. This model number indicates it it a 20" shaft model BUT I am listing the two different slow speed "Idle Air Bleed" jet sizes just in case someone along the line has converted the engine to short shaft (one hellava job if they did!).

15" shaft model "Idle Air Bleed" jet = #323703 - ID=.036 - size marked on jet=36
20" shaft model "Idle Air Bleed" jet = #323149 - ID=.038 - size marked on jet=38

Either shaft length model "High Speed Fuel" jet = #331567 - ID=.051 - size marked on jet=51D

Check float level: With the carburetor body held upside down, the float being viewed from the side, adjust the float so that the free end of the float (the end opposite the hinge pin) is ever so slightly higher (just ever so slightly off level) than the other end. And when viewed from the end, make sure it is not cocked.

Check synchronization: Back cam away from the throttle roller so that it is not touching the roller.

Remove linkage rod from one carburetor and check that both throttle butterfly's are in the closed position. Re-install that linkage rod BUT make sure that it is adjusted so that BOTH throttle butterfly's are still closed. Now, make sure that both butterfly's start to open and close at the same time.

Check Idle Timing: Adjust the cam so that throttle butterfly's just start to open when the scribe mark of the cam aligns dead center with the throttle roller. Now, with the engine running, your timing light should show between 2 to 4 degrees... not under or over! If need be, adjust the rod between the vertical throttle arm and the cam to reset the idle timing.

Fuel being blown out the idle air bleed jet? The passageway for that jet is on the other side of the throttle butterfly and crankcase pressure would need to escape past the reed plate leaf valves (intake manifold) to create that problem.

Let us know what you find.

 
Its a long shaft. I need to go take a look at the idle orifice sizes... Havent done that yet. I had them out and checked for cleanliness but didnt notice a #. Float levels are exactly as you said - the linkages between the two carbs are perfect and they are fully closed and operate at exactly the same time. Didnt get a read on idle timing with the light but I will next time I work on it. The reed valves are clean as a pin and are in great shape. (To my knowledge-- which isnt saying much) Please tell me more about checking these..If I shine a flashlight should I see no light whatsoever coming through? A few of the reeds I could see just the faintest amount of light from around the edges but nothing the smallest amount of pressure wouldnt seal. (i wouldnt think anyway) Maybe thats my issue. I will re-attack one day this week. Thank yall for giving me some fresh ideas.
 
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joereeves said:
1985 E50BELCO <---- This 1985 engine comes in two different lengths, a 15" shaft model and a 20" shaft model. This model number indicates it it a 20" shaft model BUT I am listing the two different slow speed "Idle Air Bleed" jet sizes just in case someone along the line has converted the engine to short shaft (one hellava job if they did!).

15" shaft model "Idle Air Bleed" jet = #323703 - ID=.036 - size marked on jet=36
20" shaft model "Idle Air Bleed" jet = #323149 - ID=.038 - size marked on jet=38
Click to expand...

Joe - Im going to go ahead and order some idle orifices - The Parts list on this site shows a #34 for a long shaft....http://www.marineengine.com/parts/j...LCOB&manufacturer=Evinrude&section=Carburetor
Is there something different I should know?
Just want to make sure I get the right one
 
The "used carburetors" you purchased.... are the throat measurements (front and back) the same as your original carburetors?

Reed Plates/Leaf Valves: Many of these flipper valves on engines I've worked on through the years have emitted some light through BUT crankcase pressure would slam them shut, preventing leakage. However, if there's a gap of say 1/16", any clearance that one would know was out of line... then obviously, that would create a problem.

The idle air bleed jet numbers: I'm going by one of my parts books, actually the parts book which is for the exact model number you state. Why the number is listed otherwise here or elsewhere, I have no idea. Possibly a OMC bulletin upgrade but my memory doesn't go back that far.

NOTE: Keep in mind that the slow speed jets are Idle Air Bleed Jets, meaning that they measure Air... Not Fuel, and as such... the bigger the ID hole, the less fuel is used... the smaller the ID hole, the more fuel is used.
 
The guy I bought them from said they were off a 1985 50HP J50TLCOB. Should be the same but Ill check.
And none of the reeds are even close to that. Im seeing hairline gaps that the light barely penetrates. So Id guess theyre good.
Im going to go ahead and check the numbers on the Idle jets before i buy any. Theyre clean and like new. No sense spending money on something theres a chance I already have.
 
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Having to advance the timing way forward of spec....and I mean 10 degrees or more.....just to get it to idle is a sure sign of problems in the crankcase.
Crankcase compression too low.

Now that is assuming all else checks out good...carbs, spark, compression.

I have seen it on worn out motors.
 
I agree. Somethings not right. I didn't mention it does run really good once you get it above idle. Plenty of power... Wot underway with 2 people was 5400 on the little digital tach I bought. It can't be the mating surface between the 2 halves. I took a lot of care making sure it was perfectly spotless, and just the right amount of 518...not too much...not too little. It went together beautifully and torqued to spec with zero gapping. New upper crank bearing/seal. ...should I have applied sealant to the Reed boxes before screwing them to the cover plate? And sealant to the cover gasket itself? Maybe that's where I'm losing it at.where are some other areas the crankcase pressure could be escaping? Fuel pump gasket? Where did the original vro hook to? Is there a port I missed that should be plugged? If so I sure would've thought I'd have spotted it as thorough as I went over that thing. Just brainstorming
And kimcrwbr I can engineer a device to perform the check you mentioned...so what if it turns out to be off. What would be the cause of that? The wot timing check that Joe Reeves shared is dead set on 15. Actual running Wot timing calls for 19. So that should be good huh?
 
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Got it..I'll give it a shot....and thanks again for all of your suggestions and tips
No not a new one Kim, I did dress the old one and made sure there were no burrs and all fit well. No issues noted on the flywheel fit
 
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Dont know where it wouldve originally been but I dont see any obvious open ports in the side if the block. Nothing stood out during the rebuild. I used a 1984 block for the rebuild -it may not have even had it. I painted the block and had eyes on every square inch of it. I will look again. maybe theres a bolt or plug in there thats not sealed good or something. I will do the soapy water next time i run it.

OK I googled it..behind the starter and down behind the #2 reeds. I will go straight out and look when I get off work today. I would be really shocked if I missed something like that during all Ive been over on this motor during the rebuild. I dont recall anything being there but I also dont recall what I had for breakfast yesterday. Thanks everybody for all the suggestions.
 
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Did some research - There shouldn't be a VRO pulse port for a 1984 block. But I still have the intent to inspect for low crankcase pressure next time im out. Most likely Friday.
 
Rookie Question: Whats This: http://www.marineengine.com/newpart...655+:+Replaced+by+0583387&replacement=0583387
Mines dripping the black filling material from it. Going to assume its bad. Could this be causing my Idle problems? I just figured it was an RPM sensor. Since I dont have a dash mounted tach I didnt think anything of it. Doing more digging on my motor while im slow at work and I cant find the actual function description. All it says is sensor or trigger sensor. I guess a better question is what does it do?
 
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it is the trigger/sensor that detects a change in the magnetic field of spinning magnets that are part of the flywheel. It senses exactly where the flywheel is in its rotation, and fires the powerpack at the exact proper time.
 
After I posted that last question - I found an old post that led me to believe that if that sensor and/or the powerpack is malfunctioning it could cause the plugs to fire at the same time.. I remember thinking to myself when I had the timing light on it that the flashing seemed faster than usual - and I also found it odd and couldnt figure out why I really couldnt see numbers on the flywheel very good either even though the light was flashing. Would it even run if they were firing at the same time?! I hope Im on to something here...
 
Key is in good shape. I buffed crank and inside mating surface of flywheel lightly with some fine Emery cloth to make sure there were no burrs and everything was good. I'm more curious about the sensor. How did it melt? Would that cause crappy idle but still run OK at higher rpms? I figure if its bad it would cause problems throughout rpm range.
Taking my yearly day off for my birthday and vets day tomorrow. Going at it guns blazin first thing in AM. Gotta fix this thing! Crappie are biting Iike crazy and I'm goin this weekend if I gotta paddle
 
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progator, I've had my charge coil (right next to the sensor) go bad twice with the same discharge leaking out, the second time i know it was heat related, but mine would not go above 1800. i seem to think one of my old post says some thing about it idling better after changing the coil, i think your getting close, good luck
 
Update: first thing Friday I went out and pulled the 6gal tank and put in fresh gas at 50:1. Hooked it back up and got the soapy water in a spray bottle ready to check for crankcase leak and fired it up. Idled poorly as expected then just died. Tried to restart...not wanting to run at all. Felt primer bulb and realized there was no gas in it. It was just pumping air. Swapped the primer bulb...still just air. Come to find out....the rigid tube that attaches to the bottom of the fitting going into the tank had broken completely off! Apparently it had been cracked for a while. And all the motion of pulling the can out and swapping out finally made it fall off. I "engineered" a temporary fix for it and it idles much better now. Still not perfect but I have the advance set at 3degrees and its staying alive. The carbs still need to be open ever so slightly. The melted trigger sensor should be in the mailbox Monday. I'll get that changed and maybe that'll have me back in business.
 
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Havent got around to changing it yet...lots of other irons on the fire lately. I will surely let you know as soon as I change it and test it out.
 
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