87 50HP VRO Evinrude - Could this be my problem?

FishAtFive

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I have an 87 50 HP Evinrude with the VRO system deleted by the previous owner. Been battling rough idle, and after running for awhile it is darn near impossible to get started. Replaced the entire fuel and ignition system, runs better but still having the problem. I was thinking, what could cause a fuel issue but not be part of the fuel system? So on a hunch I checked the now unused VRO pulse fitting on the crankcase and I can see that it was plugged with a short hose which is lose and cracked. I am thinking the fuel pump is not getting enough vacuum because of this. Could I be right? I won't be able to test until the weekend, and if you all say it can't be the problem I can move on and look at other stuff in the meantime. Here is a video of the leaky hose:

 

racerone

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That pulse fitting is NOT USED on a regular fuel pump.----The regular fuel pump operates with PRESSURE and not vacuum.-----The regular fuel pump operates off the top crankcase.----The VRO operated off the bottom crankcase.----Remove pulse fitting and put in a pipe plug.
 

FishAtFive

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That pulse fitting is NOT USED on a regular fuel pump.----The regular fuel pump operates with PRESSURE and not vacuum.-----The regular fuel pump operates off the top crankcase.----The VRO operated off the bottom crankcase.----Remove pulse fitting and put in a pipe plug.
For now I have just replugged it with a fresh hose. If it fixes the issue I will get the plug (321164 - Manifold Plug). So it sounds like you think this could be the issue?
 

FishAtFive

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Install the pipe plug, find one at your hardware store.---.----Then test run !!
If only I could. Work and school ensures that will not happen until at least Saturday, and if we don't get some rain there won't be anywhere to take it.
 

FishAtFive

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Just an update, although I am sure this pressure leak was impacting performance, it has not solved my issue with stalling and hard starts when in the water (perfectly fine on muffs). I'm currently wallowing in despair and plotting my next move.

Here is the problem:

1) Hard to start cold, but doable.
2) After running for awhile and then stopping, the longer I wait to restart it, the harder it is to start. It eventually starts but I need to try over and over again. The longer I try, I can tell the more it wants to start, until it finally does. I am thinking this is a fuel issue, so I am considering the following, in order:

1) Disconnect the starter, then disconnect the fuel line to the manifold and reconnect it to a clear tube running back to the fuel tank. Run the starter and confirm good gas flow with no air leaks.

2) Rebuild using a proper carb rebuild kit (not Amazon). Here is a video I took awhile back of what seemed like a sticking needle, but it did the same with all four needles and brass receptacles I had handy, so I just figured that is how it is supposed to be (requires sound):


And if that fails, I will accept failure and reach out to the local outboard mechanic.
 

Mc Tool

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Are you giving it a bit of throttle ( fast idle lever ) when your trying to start it ?
 

racerone

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These motors in good condition and the correct starting procedure start almost instantly.----Post the actual compression values here.----And describe in detail how you try and start this motor when cold!
 

Crosbyman

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the clip on the float is meant to pull out the inlet needle when the float lowers down..... when fuel is sucked out... should not be the problem after 4 kits !

the 87 50 hps seems to using old style carbs please post your engine mdl #

to idle properly means a clean carb idle circuit . the side channel feeding fuel to the top portion uses the side channel which is very narrow and 3 small drip holes under the top plug.. everything must be cleaned out and blown dry.

before reassembly of the carb try a blow test on the fuel inlet... "air in upright" "no air in upside down" float must be level with the carb body



check choke operation during the start attempts. check/clean orifices in yellow
1760529544016.png
 

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FishAtFive

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Crosbyman, thanks that is a lot of good information you have provided. The engine model is E50TLCUD. On the third rebuild I removed the plug and cleaned all of the top circuit. I was not aware of the side channel, I figured the small inner tube was how the fuel made it to the idle circuit? I will take them back apart and make sure that is clean as well - as well as the blow test. If I recall correctly when I held the carb upright the float does drop so that lead me to think that even if the needle was sticking, it should at least fill the bowl and idle.

While I am in there I plan on checking all the fuel lines for air leaks all the way to the tank, and I will recheck the primer solenoid as well as you suggest.

Racerone, I checked the compression when I first got the motor as well as after the impellor went out. Both times each cylinder was betwen 140 and 150. I will check it again, this time cold and after running it a bit, maybe that will show a difference.

Mc Tool - yes since this happens all the time I have tried all sorts of differnt things. I have tried with the idle lever in various positions, I even take the cover off and fiddle with the timing advance, moving forward, backward, opening the throttle, not opening the throttle, nothing seems to make a difference. What gets it started is I simply give it a try then wait 30 seconds to a minute, then when I try next it starts a little more until after a bunch of tries it finally catches.
 
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FishAtFive

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Post your cold starting procedure in details!----You may be omitting a simple step.

Cold start - on the muffs, I open the gas tank vent, squeeze the bulb until firm, turn the key - it usually starts. But if it doesn't, I'll push in the key briefly and that ususally gets it going. Raise the idle lever and let it warm up for a few minutes. Usually in about 30 seconds to a minute it starts to rev and I lower the idle lever.

Cold start - in the water, the same as on the muffs but I really need to work various combinations of choke, lever, etc, until it finally starts.

Warm start in the water after sitting for about a half hour - I just about kill the battery trying to start it. Only way is to get it to catch and quickly raise the lever to rev it up before it stalls. Raising the lever before it catches does not work.
 

Crosbyman

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I'll push in the key briefly and that ususally gets it going.
that chokes the carb and forces the crankcase vacum to pull in more fuel to ignite.
have you tried choking it ......key pushed in and START when warm starting ?

every motors are finiky ...I remember my Merc 500 few could start it...but me.
 

racerone

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The key is to be pushed in AND held in while cranking it over.----That should make for near instant starting.----When motor fires, stop pushing in on the key.----Push key in as needed if motor falters.
 

FishAtFive

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Have you tried pumping the primer ball when this condition exists? What do your spark plugs look like when all this is happening?
No, I have not simutaneously while starting but I will try. I'm usually alone when this happens so I have tried pumping the primer ball then going back to the console and turning the key. It's typically soft (but not collapsed) when I first grab it, and then it gets firm right away. I'll take a look at the spark plugs the next time I can work on it. I assume what I should be seeing is that they are wet, right?

Edit: also I plan to run a test this weekend, disconnect the fuel lines and splice them to a clear line running back to the fuel tank. Disconnect the starter +. Crank and check for air bubbles and decent flow, including the primer circuit when the key is depressed.
 
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racerone

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With plugs in the cylinders , does spark jump a gap of 3/8" or more ?.-----Sounds like there are issues with your battery and starter motor.----This is all so easy to sort out with some simple testing on your part.----You have checked the flywheel key?----You have tested the operation of the wonderful primer valve?-----Does motor start with primer valve in the manual position ?----Remember that I can not see , hear or touch your simple ( to me ) motor.
 

FishAtFive

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With plugs in the cylinders , does spark jump a gap of 3/8" or more ?.-----Sounds like there are issues with your battery and starter motor.----This is all so easy to sort out with some simple testing on your part.----You have checked the flywheel key?----You have tested the operation of the wonderful primer valve?-----Does motor start with primer valve in the manual position ?----Remember that I can not see , hear or touch your simple ( to me ) motor.
Thanks, I have been meaning to test the spark jump. I have on order the tool to test that, it should be here by the weekend and I will give that a try. I should have done it sooner. I noticed the original flywheel key was a little bent the first time I took off the flywheel. I have since replaced that and taken the flywheel off twice to replace the charge coil and timer sensor and both times the flywheel key was still good. I am fairly certain the primer is working fine, I can use it to goose the engine and I also can hear it engage the solenoid. But I plan on rechecking all that this weekend. I'm sure if any of you were in the neighborhood I would have this worked out months ago. There is no substitute for just seeing it in person.

Edit: the battery is new and is holding it's charge. I can see the volts on my fish finder and it's typically 12.8 or higher, except when it doesnt want to start and I beat the crap out of it. But once I get it started and drive around a bit the voltage returns to around 12.8. I need a cheap way to see the RPMs so I can know if the starter is working correctly.
 
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