Cannot get this E8RERE running right, please help?

1994 Evinrude 8hp E8RERE:

Still fighting this motor to get it running right.

It starts easy cold or warm, when cold it seems to like 1 pull on choke, one or two pulls no-choke and fires right up.

Once warm starts easy with no choke and some throttle.

@Edchris177 sent me a service manual which is for the exact year, so I've been through a lot of that. Here is what I've done so far:

- Disassembled the carb completely twice. Clean as a whistle. The three little tiny tiny holes on the top of the aluminum carb housing are 100% clean and clear. Plastic top cover seems to be in good shape. The upper and lower gaskets around the well were in bad shape so those have been replaced. All other gaskets are in good shape. I have adjusted the mixture screw to find the highest idle RPM after warming the engine up and backed off 1/8th of a turn. You can go from idle to full throttle and the engine doesn't backfire or surge which to me seems to indicate the mixture is set in a good spot.

- New plugs, gapped .030, with maybe a couple hours on them between testing in a drum and at the lake
- Followed the link & sync procedure to a tee and made all appropriate adjustments.
- Compression is good
- Checked fuel pump screen, clean as can be
- No leaks from fuel lines, replaced fuel line quick connect as the one I got with the motor was leaking when squeezing the bulb to prime.
- Adjusted float level so it's level with the carb housing when the housing is upside down, and the bottom hangs 1 1/4" below the carb housing when measured holding the carb right-side up. Primes fine and stops letting fuel in when bowl is full.

To do the following electronic tests I've used a Fluke 88V in peak MIN/MAX mode to take the voltage readings. I'm not sure how this compares to the DVA Evinrude suggests using, but it takes a reading at 250 micro-seconds which from what I have read is perfectly acceptable for ignition voltage readings. My findings mirror the figures in the service manual so I'm inclined to believe it's accurate for these tests.


- Tested the stator voltage - 312v when cranking
- Tested the stator for shorts - no shorts when cranking, or when twisting the throttle handle
- Tested stator resistance - 950 ohms

- Tested sensor coil for shorts - no shorts when cranking, or when twisting the throttle handle
- Tested sensor coil voltage - can't remember what it read, but it was WAY above the 1.5 volt minimum. Want to say I got 20-30+ volts.
- Tested sensor coil resistance - 42 ohms

- Tested ignition coil primary resistance - 0.1 ohms on both 1 and 2
- Tested ignition coil secondary resistance - around 300 ohms both 1 and 2

- Tested spark plug wires - tested good near 0 ohms, checked while wiggling wires to make sure no shorts.

- There were some tests on the power pack that looked like they need some special equipment to do, so I took a chance and ordered a new CDI one. I hate throwing parts at a problem, but at least now I have a spare. No change.

- The one test I haven't done yet that I would like to do is testing the spark with a gap tester to make sure it can jump the 1/2" gap the service manual suggests. Not sure where I left my tester and haven't found it yet.

Issues I am having with the engine (see video below):

The engine seems to have a miss or be "4-stroking" a lot. Seems to idle well to my ear, but at mid/high RPMs in the test drum it does not seem to be running as smooth as it should. On the lake _IF_ it can get my small inflatable up on plane it runs well at higher RPM, but it struggles the whole time to get it up on plane and seems low on power due to the rough running. Mid-range RPM results in some rough running.

It's difficult to get the idle speed below around 850 RPM while in gear without stalling. It will do it, but going from a higher RPM back idle set below this point will generally cause the engine to stall unless the throttle is brought down VERY slowly.

I'm about at my wits end on this one - I have not pulled the flywheel yet to inspect how the stator and coil look, as I guess there is a possibility there could be an issue there even though the components test good.

Here is a video of the engine running in a drum.

I would really appreciate any further advice. Happy to do whatever testing I can with the tools I have available to provide further information, I'm a truck mechanic. I have a timing light although I am unsure how well it will work with the high RPM of the 2-stroke.

Thanks!!

I have the carb off again (lol) and noticed something interesting.

Is it possible this carb has the wrong gasket, and/or the top cover is mismatched? Here are some pictures - the black gasket is the one that came on the carb when I bought the motor, and is the one I have had on it all this time. The kit I ordered came with three gaskets, and the one with the "Y" shape seems to match "Y" at the rear of the carb, whereas the black gasket doesn't have this. The number on the top cover (436762) does seem to match the correct number from the parts page for the engine of this year. The number on the carb (MX338528) doesn't match anything.

Need to use a OEM kit..the red gaskets die quickly and only one with notch will work.

faztbullet said:

Need to use a OEM kit..the red gaskets die quickly and only one with notch will work.

Click to expand...

Thanks, yeah I have a Sierra kit coming as well, just got the cheapo one too 'cause I could get it here fast to do some testing. By the notch I'm guessing you mean the one with the notch missing from the gasket instead of just the hole - the one to the immediate right of the black gasket in the picture? Thanks!

I forgot to put compression readings in the original post, cylinder 1 and 2 read 116 and 117lbs respectively, cold, after running the carb dry and the engine sat overnight.

I pulled the flywheel off. The area around the upper crankcase seal is wet, looks like the seal may be leaking a bit. But not much. I put some soapy water around the area and spun the engine over, didn't see any bubbles. I'm sure it needs to be replaced, but I can't see it being a big enough leak to cause running issues. Not sure how I would tell if the lower seal is leaking or not...

I checked all the wiring to the ignition components under the flywheel. Didn't see anything chaffed or worn and shorting out.

Alright, last update for now till I get some more testing done. Put flywheel back together. Tested for shorts on the wires between the sensor and the charge coil just to make sure that there was no way they could possibly shorted to each other causing some erratic ignition issues. Didn't see anything. Tested the sensor again, still has a relatively high voltage (was seeing 15+ volts) out of the sensor with the Fluke meter on peak mode. On normal, non-peak mode, I get a reading of about 0.5 volts.

Dug through the service manual and in the principles of operation section it states the sensor should produce around 3 volts. The testing section says I should see at least 1.5 volts. I'm either seeing way over that when testing for peak voltage, or under that when using the multimeter in a normal mode.

So, either the DMM is having trouble reading this component without the use of the DVA adapter, or the sensor is bad. Ordered a DVA adapter for the multimeter, and a new sensor. Will do the testing with the DVA before installing the new sensor. If it tests good, will return the sensor I ordered. If not, will install that and see if it solves my problem. Will redo all of the ignition tests with the DVA adapter just to confirm. If I still can't get this thing running right, I'm probably gonna swallow my pride and take this thing to my local marina which has a pretty good reputation.

Frustrated for sure.

Update on this little motor:

I ordered a DVA adapter for my meter to verify my ignition component readings.

Whether the $30 Electronic Specialties DVA adapter plugged into the Fluke, or the $550 Fluke 88V on peak mode is more accurate for ignition testing purposes, I can't answer. For example, the Fluke on peak mode would read 300+ volts for charge coil voltage, the DVA reads 275. Fluke reads the sensor coil at 20+ volts, DVA would read around 15 or so. DVA appears to work like some kind of a capacitor that charges up to the max voltage for the DMM to read, then it drops down, maybe through some kind of a load resistor. I'm curious how it actually works.

Regardless, I installed the replacement sensor coil and it now reads around 5 volts through the DVA. Much closer to spec, but still higher. It has not solved the mid-high range 4-stroking/miss, but it did make a huge improvement with the engine returning to idle. It will happily return to idle now and continue to chug away. I still can't get the RPM down low enough to meet spec though.

I finally found my adjustable spark tester and found that the ignition coil would fire a spark across almost a 3/4" gap for #1, but #2 would barely jump a 1/4" gap. I hooked up some spark test lights between each plug and wire and ran the engine and noticed an occasional miss on #2. Not for any length of time, but a drop here and there.

I'm inclined to believe my final issue lies with the ignition coil even though the resistance tests all look good. I sure hope so. I really feel I'm down to a spark issue causing the rough running, especially it can be somewhat random. At mid RPM, one second the engine is running a bit rough (but not rough enough to be firing on 1 cylinder only), the next its purring, then back to a bit rough again.

The small win with the new sensor improving return-to-idle performance has my hopeful I can get this thing running right and out on the water. Ignition module should be here Sunday. Will post an update then.

New ignition coil got here today. Threw it on the motor, nice blue spark will jump a 3/4" gap no problem on both cylinders now. Starts much nicer at low RPM now that both cylinders are getting a strong spark. Will also start and run briefly with the choke completely on now which it wouldn't do before, guessing it was too rich of a mixture for that weak spark on that one cylinder. Had to give it a pull on choke, then push the choke in and another couple pulls to get it to fire when cold. Now it will fire with the choke on.


But this thing STILL won't smooth out in the midrange, gets the shakes to it.


I swear this motor is CURSED.


Pulled the exhaust covers off to have a look in the cylinders. Pistons look great to me. It is interesting how cylinder #1 has the dark spot on it (guessing some carbon buildup?) between the upper and lower rings, whereas cylinder #2 has none. Cylinders had some light scratches on the thrust axes but for a motor from 1994 looked OK to me, honestly the crosshatching looked really good and I didn't see any glazing. There is that one wider mark on cylinder #2, but I swear I can see the crosshatching over it. Not sure what that is. Can't get my finger in there to feel anything, but it all looks really good to me for an engine of this age.


Pulled the carb mounting plate off to have a look at the reed valves. They are all sitting nice and flat against their plate and nothing appeared bent or held open.


The gaskets tore off pulling the exhaust covers off, so I ordered a powerhead gasket kit since that was cheaper than buying them individually. Plus it appeared to include the upper and lower crank case seals which I at least know I will need to do the upper at at some point. How do you know if the lower is going bad?


Can't take it out to the lake to really let it run until those new gaskets get in. Was hoping they would stay in one piece, but they're probably the original gaskets so that's not surprising.


I've attached a picture of the reed valves and a video of the piston/borescope footage looking in the cylinders from the exhaust ports.


So, where am I at now with this thing? Gonna go look at a Tohatsu 6hp 4-stroke on Craigslist LOL. Beach trip with my family coming up soon and want to have the boat to putz around in. Just don't think it will be with this motor this time around.


Definitely not giving up on this thing, I really like the power/weight ratio of a 2-stroke and it's just the right weight for it to not be a pain to throw in the back of the truck and take to the lake. Plus I have put WAY to much time and money into this motor to not get it running right.


I'm truly at a loss now as to what could be causing the problem. All the spark issues seem to be resolved with the new sensor and the new coil. Inside the engine looks good to me, as far as I can tell without splitting the crankcase open. Guess that puts me back to a fuel/air issue. I fail to see anything wrong with the carb now, but it's obviously there is an issue with some part somewhere on this engine. With the fixed timing on this engine I don't see how that could be any issue. The plate that moves with the twist throttle that has all the ignition components on it is secure and not loose or flopping around.


I guess before I go spending any more time or money on this thing I will put it all back together, take it out to the lake and fine tune everything best I can and see how it runs and go from there. I'll be sure to get some video in case it might help.

For what it's worth the one curious thing I find about this carb is the fact that the mixture needle needs to be around 6 turns out to get it in the sweet spot. The manual says to start tuning at 3 turns. This thing won't even pretend to stay running at 3 turns. Running too rich would explain what could be 4-stroking that I'm interpreting as running rough.

The needle seat looks OK to me, though it's in a plastic housing so who knows.

Thoughts on the 6 turns out on the idle mixture? Is it normal to have some carbs that just need quite a bit different adjustment compared to others, or could I have some deep seated issue in the carb (or air getting in from somewhere else causing me to need to run the carb really rich??)

OEM parts or nothing.

Upper or lower crank seals maybe? Have you serviced the fuel pump?

When you cleaned carb - did you let it soak in product overnight? Also, are there any led plugs on that carb? If so, did you pop them off and inspect orifices?

bigtime_mcalpine said:

Upper or lower crank seals maybe? Have you serviced the fuel pump?

Click to expand...

Upper crank seal weeps a tiny bit, just enough to cause some dampness around the area, did the soapy water test on it did not see any leaks. I will need to replace it but don't believe its leaking anywhere near enough to cause running issues.

Is it possible to test the lower crank seal? Or is there something to look for to know it has issues?

I have taken the fuel pump apart and did not see any leaks. But this was one of my thoughts, if fuel was leaking past the diaphragm directly into the intake manifold (or maybe its just the crankcase on a 2-stroke?) that could cause it to run really rich. I have ordered a new pump from Sierra and a rebuild kit for this one as well. The one that is on there appears to be a no-name pump, probably a Chinese clone, so I'll just replace it, rebuild it, and keep it as a backup.

Can I gravity feed the carb, bypassing the fuel pump, to test? Would gravity supply a sufficient amount of fuel to the carb on this engine?

<duplicate post>

bigtime_mcalpine said:

When you cleaned carb - did you let it soak in product overnight? Also, are there any led plugs on that carb? If so, did you pop them off and inspect orifices?

Click to expand...

I didn't soak the carb, but I completely disassembled it and cleaned everything out. There are no lead plugs on that carb. I blew carb cleaner and compressed air through every single passage on the carb. I don't believe there are any hidden passages underneath any plugs on this one. The only "plug" is a small screen on the side that appears to be some kind of a passageway to let air in. It is clear. You can see it in the center of the aluminum body of the carb on the bottom in this picture.

Ok, so I made some temporary gaskets which (mostly) sealed things up at the exhaust cover, ran fuel line straight from tank to the carb, ran it lightly squeezing the primer to keep the bowl full. Still didn't run right. So I don't think the fuel pump is to blame. It'll be replaced regardless when I get the new one.


So I went ahead and separated the power head from the mid section. I see quite a bit of what I would assume is oil around the lower crankcase seal, very milky looking.


Looking at the exhaust it looks like that "manifold" piece directs the exhaust deeper down into the midsection. So I would this all of this oil would have to be coming from the lower crank gasket. Maybe it's worn to the point of sucking air back into the crankcase here, screwing with the mixture?