92 Evinrude 8hp Hard Starting/No Idle E8RENM

Good Morning, I'm new to the Forum but I've been scouring through posts trying to find suggestions. I picked up a 92' Evinrude 8HP a few months ago and have which had a hard starting issue but seemed to run and idle great (in test tank) once finally running. After playing with it to diagnose the problem, I now have the same hard start issue and it's not idling properly either. Originally, it would require many many pulls to get it running, a little shorter after pulling the plugs and cleaning with a wire brush and heating with a small torch to dry them off. Always, and still do come out oily and wet after it has been running. Motor will not re-start no mater how long it has run.

I'll list what I have done, and the results so far.

- Performed simple spark check (ground plug to block method) - Spark on Both Cylinders
- Tried adjusting mixture screw. Initially had to turn in about 5-6 turns to seat (very Rich). Started with 1.5 turns out, then 2.5 (as per service manual). Doesn't seem to make any difference in either direction based on these starting points.
- Adjusted Throttle Cable and possibly fixed inoperable idle speed adjustment in tiller
- Removed and Cleaned Carb (without kit) - No Change
- Replaced Spark Plugs - No Change
- Replaced Power Pack/Ignition Module (UFI Ignition) based on Marine Mechanic/Friend suggestion - No Change
- Performed Compression Test - 70-75psi on both cylinders
- Performed Proper Spark Gap Test - Good 7/16"
- Performed Decarb using 1 can of Deep Creep - No Change

Notes:

- Somewhere in the process of readjusting the throttle cable and cleaning the carb, I found it would only stay running at higher RPM (guessing somewhere around what I presume the START speed (sorry markings are gone on tiller), any lower and it died, but seemed to still rev up good.
- I have been adjusting the mixture screw throughout the process and have now opened the screw back to around the 5-6 turn range. It now seems to idle at a much lower RPM but not nearly as low as it originally did (would still idle with throttle control closed).
- Above note leads me to suspect some sort of air leak causing a lean condition thus requiring a rich mixture to compensate, however I still get oily/wet fouled plugs after it runs no matter where the mix screw is set.
- Compression, although even, seems low to me - could this be the cause of my no/hard start issue?
- Power Pack, do I have the correct air gap between flywheel. I don't have the proper spacing ring so I installed based on alternative procedure in service manual by using approx .025" of masking tape on magnets and looking for marks from components. How critical/sensitive is this air-gap and could it be causing my issue still?
- In order to rule out carb issue, I have dissassembled and very thoroughly cleaned the carb but waiting on repair kit for assembly. I did notice the little mesh screen on the carb above the bowl was partially plugged by something, possibly excess Seafoam as it seemed like a liquid IIRC.
- Although seems OK, I will be rebuilding the fuel pump (kit also on order) just to rule out any weird issue. Have not had any fuel starvation issue while running and primer stays hard.
- Fuel Tank and Line are brand new, with about 1 week old gas. Fuel pump supply line was leaking at fitting (loose connection) but has since been repaired. Lines will be replaced but are not leaking, and I see no evidence in the carb of line breakdown.

Thanks for reading, sorry for the long post, just trying to be as thorough as I can. I look forward to any suggestions you may have.

The compression could be better and probably will be when the engine is running normally... and if the spark is a strong blue spark... a real SNAP when jumping that 7/16" gap, that's okay also.... and that leaves the fuel to be a possible problem unless your starting procedure is flawed.

Exactly what is your starting procedure?

The carburetor cleaning.... Did you manually clean the high speed jet with a piece of single strand steel wire? If not, do so as solvent just doesn't do that job properly. Fuel must freely flow through that HS jet before it can flow to any other fuel passageway. Whatever tubes exist on that carburetor, make sure that they are perfectly clean. Restore the carburetor to new condition with a kit.

The wet spark plug scenario you mention suggests carburetor flooding, sticking choke butterfly... or weak ignition which you'll need to be the judge of.

The spark plugs best suited for that engine are the Champion QL77JC4 or L77JC4 plugs gaped at either .030 (long life) or .040 (strong spark)... The "Q" indicates a suppressor plug, designed to quiet engine interference in ones electronic equipment.

Let us know what you find.

Hi Joe and Moose. I have changed several upper crank seals on these. Ethanol related. I keep a couple damaged ones on top of my work bench to show customers.

joereeves said:

The compression could be better and probably will be when the engine is running normally... and if the spark is a strong blue spark... a real SNAP when jumping that 7/16" gap, that's okay also.... and that leaves the fuel to be a possible problem unless your starting procedure is flawed.

Exactly what is your starting procedure?

The carburetor cleaning.... Did you manually clean the high speed jet with a piece of single strand steel wire? If not, do so as solvent just doesn't do that job properly. Fuel must freely flow through that HS jet before it can flow to any other fuel passageway. Whatever tubes exist on that carburetor, make sure that they are perfectly clean. Restore the carburetor to new condition with a kit.

The wet spark plug scenario you mention suggests carburetor flooding, sticking choke butterfly... or weak ignition which you'll need to be the judge of.

The spark plugs best suited for that engine are the Champion QL77JC4 or L77JC4 plugs gaped at either .030 (long life) or .040 (strong spark)... The "Q" indicates a suppressor plug, designed to quiet engine interference in ones electronic equipment.

Let us know what you find.

Click to expand...

Thanks for the quick reply, sorry I can't respond sooner. My starting procedure which sort of seems to work is as follows;
1) Prime until bulb is hard as it will get (never gets rock hard).
2) Engage full choke
3) Throttle to what I define as starting position (about 3/4 throttle). I have no markings on the handle.
4) Pull Rope repeatedly until I can feel it trying to start, best described as less resistance and easier to pull.
5) Disengage Choke, and continue pulling until it fires up or starts to get harder to pull over again. If no start, then reengage choke and repeat as necessary.

This is the procedure which seems to work sort of consistently. I got it to start once with full choke (every other time no choke), but it died within a couple seconds but then I realized I forgot to apply throttle and also hook up/prime the fuel line...oops. Hmm. now that I mention this it has me thinking...it did start after only a few pulls if I recall correctly.

As for the carb cleaning, every passageway I can see is spotless and I can see clearly through them. I'm not sure which jet you are specifically referring to? Is it the long brass tube going down to the bowl from the body?

As for spark, I am going to double check the quality of the spark, its so hard to judge during the day while pulling on a rope in the opposite direction. I'll try having someone else pull so I can see better.

As for plugs, they are QL77JC4 gapped at .030"

timguy said:

Hi Joe and Moose. I have changed several upper crank seals on these. Ethanol related. I keep a couple damaged ones on top of my work bench to show customers.

Click to expand...

Thank You for the response. Is there anyway the seal can be inspected to verify this is the case besides doing a cylinder leak test? Also how difficult would it be to change? I'm assuming there would be a special install tool required, is there a makeshift tool available like a deep size socket? For the price of this seal it's probably worth changing just to eliminate the possibility depending on the difficulty. I'm going to look at the service manual now to see.

One question, I had mentioned that I replaced the ignition module using about .025" of masking tape. It keeps nagging in the back of my mind that it's not installed with the appropriate air gap between the flywheel. Any thoughts on this? How critical is the spacing both for the module and the charge coil and what symptoms would I get if it's not set right?

Thanks Again!!

Yes, you need a helper with the spark test unless you have a air gap tester you can clamp in your viewing area. A dark area helps.

Any component mounting on the timing base/armature plate under the flywheel (your question pertaining to air gap)... Notice the aluminum area where the component sits... notice the very slight bevel there... the vertical portion of the component should align as perfect as possible with the inside bevel of that seat. This creates the ideal factory air gap between the component and the flywheel magnets.

The Fuel Primer Bulb "must" become rock hard... otherwise, the valve(s) within the bulb are faulty, the carburetor is flooding, or the fuel pump diaphragm is cracked and leaking fuel into the crankcase. Find out which and correct.

The long brass tube you speak of going down through the body of the carburetor, if a fairly large ID tube would be the high speed nozzle (a simply passageway)... if a very small ID tube, that would be the passageway for the fuel to travel to the slow speed passageway at the top of the carburetor.

The high speed jet will be found screwed sideways in the large fitting at the extreme bottom of the carburetors center portion (the fitting resting on the float chambers bottom). I suspect it will have the number 50 imprinted upon it (let me know).

Your starting procedure is close to what it should be, however... here is what I suggest you change to:

1 - Have the fuel primer bulb pumped up hard. (If it doesn't get hard, find out why & correct).
2 - Pull the choke all the way out.
3 - Apply some throttle to take the throttle butterfly off the idle setting.
4 - Holding the throttle in position, engage the starter pawl in the flywheel then pull it briskly.
5 - When the engine actually starts running or simply fires, push the choke in so as not to flood the engine. Sometime, when the engine is cold, it is necessary to "play" with the choke until the engine warms up.

The engine should start within 3 pulls... no more than six or something is not as it should be.

The hyperlink below... see # 23... The one that states the ID size to be #50 (.050 .

http://www.marineengine.com/parts/j...8RENM&manufacturer=Johnson&section=Carburetor

More Info Below.............................
If I missed anything, let me know. Also let us know what you find.

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(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
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Spark testers available at your local auto parts store, or build the following:

(Spark Tester - Home Made)
(J. Reeves)

You can use a medium size philips screwdriver (#2 I believe) inserted into the spark plug boot spring connector, then hold the screwdriver shank approximately 7/16" away from the block to check the spark or build the following:

A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.

Using the above, one could easily build a spark tester whereas they could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:

..........X1..........X2

.................X..(grd)

..........X3..........X4

This can obviously be modified to a 6 or 8 cylinder setup tester.
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A leaky top crank seal will show oil below the flywheel and possibly splattered around from centrifugal force, inside scowling. Does that carb have the tiny clear yellow line in the float area that Joe mentions? Ethanol likes to eat them up.

Thanks for the help guys, the tube I was referring to was the brass tube built into the body of the carb in the centre of the bowl which if I understand correctly the High Speed Nozzle sits around and has the High Speed Jet screwed into, so not the right one. I will make sure I get some wire through that high speed jet before re-assembly although it does look very clean already. And yes, this carb does have the rubber tube inside although mine is black, but I see it comes with the rebuild kit so it will be replaced during re-assembly.

As for the bulb, as I mentioned it does get firm but there is some "free play" for lack of a better description. However, if I squeeze harder I can hear fuel flow so you maybe onto something here. Is it possible to overcome the pressure of the float on the float valve with the primer bulb? If the pump diaphragm is leaking fuel into the crankcase, would I not get symptoms of pump failure ie. rpm fluctuations, loss of pressure in the primer etc. or would it still operate? My understanding of how these pumps work is very limited.

Regarding the ignition, I'm going to double check the spark condition but I think now I have the placement of the components correct if not pretty close. I'm going to pull the timing plate off and look at the crank seal timguy mentioned at the same time and confirm the placement at that time. Unfortunately the mounting tab where the bolt goes through on the starter has broken (it was cracked already) so I have to repair that now also, hopefully I can use some JB Weld to fix it at least temporarily.

I really can't wait until the parts arrive and I have time to tackle this. I'm feeling more confident that I might actually get this running properly without a rebuild. I'll definitely post an update once I've made some progress.

The fuel pump will still work with a damaged diaphragm but depending on how severe the leak gets. The pulses created by motor compression/vacuum cycles is what moves the diaphragm and creates fuel suction through a couple check valves inside the pump. I don't think that the black hose is factory, but I am not sure of this for your exact model. If I'm right, that would mean the motor has been worked on with ethanol damaging the original tube. Therefore we can now suspect more ethanol damage in other components like fuel pump and seal. If the seal is leaking it will be evident by a visual inspection of the areas under the stator/flywheel. You would not need to remove the plate that holds the ignition components to notice the leak, but if you want to replace the seal, then you would remove the plate. Finally, yes, you can put enough pressure with the primer bulb to overcome the float/needle and flood the motor. If you have decent firmness when squeezing the primer bulb, it is likely okay, but ethanol fuel can damage any rubber composition parts. The check valve in the primer bulbs are a harder composition plastic and can endure ethanol. The carb nozzle/tube that you are speaking of which runs vertically needs only to be inspected for deposits and carefully cleaned. I use automotive throttle body cleaning spray which is so strong it can soften most plastics. But if there is no evidence of oxidation, or deposits, regular carb cleaning spray is fine.