1994 Evinrude ELERM30: got fuel, got spark

[CPT MOTU]

I’m reaching out to get some fresh thoughts on my boat engine ‘’no start” situation. My 1994 Evinrude 2-stroke ELRM30 (30hp) in my boat wouldn’t turn over the other day (just a hum) after starting and running fine 7 days prior, including starting and running fine for many years. I immediately put my meter on the older battery and metered 12.5V. I popped off the engine cover and attempted another restart and saw the starter engage the flywheel but struggle to turn the flywheel more than 1/4 turn before humming again. I successfully pull started it (with the aid of starting fluid) and ran it around the lake for about 1 hour. After stopping at the sand bar for a couple hours, I successfully pull started it again and ran it for a few minutes before noticing my fast idle lever didn’t want to go all the way up (like a spring was preventing it from the max idle position). Weird. Then I noticed the engine RPM wouldn’t respond to my fast idle lever position (RPMs stayed low no matter what position the lever was at). Really weird. Then I shut the engine off to look at the linkage and cable. Then, I couldn’t get it to start after multiple attempts at pull starting with starting fluid (only got some “snorts”). Battery metered at only 10.5V at this point. I got towed to shore and replaced the battery. I stupidly reversed the polarity on the new battery connection and didn’t notice until I turned the key and observed complete silence. After saying “oh ****” and fixing the polarity/connections, I still could only get some snorts. I was worried that reversing the polarity for a second might have blown something, because I know that can be detrimental. Either way, I was hopeful that I might have just fouled the plugs and I just needed to verify a good spark and my starting fluid would do the rest. Two days later, I put fresh plugs in and verified spark (via in-line spark tester). I even verified that the old plugs had spark before putting in the new ones. I still can only get some snorts, during multiple attempts at starts. I’ve never had a situation where starting fluid wouldn’t bang after verifying spark. I did notice (and fix) one more thing after replacing the plugs: a thin braided ground cable was severed that goes from the starter to the engine chassis. Not sure how long it had been severed, but fixing it didn’t change my “no start” situation. Any thoughts? I suppose the spark that I “see” in my tester might not be hot enough under compression if the coils are lethargic all of the sudden. How else can a spark NOT ignite starting fluid (i.e. I’m ruling out a fuel delivery problem). Help!

 

[boobie]

Will your spark jump a 7/16" gap on an open air gap spark tester ???

 

[Bosunsmate]

As Boobie says, if it passes that then check timing

 

[racerone]

Pull the flywheel now.-----Sounds like a sheared key or something came loose under there.

 

[CPT MOTU]

Thank you boobie and Bosunsmate. My in line spark tester, unfortunately, doesn’t have an adjustable gap. I’ll try to pick one up. I didn’t think to quantify “how good“ the spark was by seeing how far a gap it will jump. Makes sense. What would cause my timing to be all of a sudden bad? I thought the timing on a stator-based system was pretty fixed, no? The timing could just suddenly go out of phase with no warning signs? Thanks again.

 

[CPT MOTU]

Thank you, racerone. You thinking maybe my pull starting the flywheel caused something? Didn’t think of that. The flywheel feels “normal” when I rotate it by hand, but your point is certainly something to consider. Thanks again.

 

[racerone]

You are stating that your control box was behaving differently.----That is a clue for me that something is wrong.-----But your motor is very far away I think and you have to do the inspection and work !!----Sorry if that is not what you want to hear !

 

[CPT MOTU]

Troubleshooting Day #3: Pulled flywheel - woodruff key and keyway look fine. What is meant when racerone says: “your motor is very far away I think and you have to do the inspection and work”??

 

[CPT MOTU]

Troubleshooting Day #4: Split open control box and found that the fast idle cable is seized (stuck in low speed idle position). This explains why the engine rpm was unresponsive to the lever position. Linkage inside the control box just rocks back and forth without pushing the cable in and out. Not sure how the seized cable would cause my engine not to start, but I will need to replace the cable anyway. On the engine side, it looks like the butterfly valve on the throttle body is at the closed position. I’ve tried starting it while holding the butterfly valve open too, but still all I get is a couple snorts once in a while. Might as well measure my cylinder compression while I’m at it too...

 

[Bosunsmate]

Yep test compression and spark then you will know a lot more

 

[CPT MOTU]

Troubleshooting Day #5: Fixed! I feel so stupid. As I was disconnecting the fast idle cable to measure its length (to replace it), I discovered that the linkage between the fast idle cable and the throttle body was bound up. A little WD40 and some cycling back and forth allowed the lever to go all the way up at the control box and the butterfly valve in the throttle body to open up, respectively. Took to the lake, started right up like it used to do, and spent all day crusin and swimmin! I didn’t know that outboards linked ad advancing the timing with RPM increase, via linkage. Makes sense now!

 

[Bosunsmate]

yep thats what link and sync is all about, if they dont change in tandem she will never run properly. Sounds like a great day out