2 Stroke Outboard No Spark Diagnosis Part 2

This is part 2 of diagnosing a 2-stroke Mercury 15hp outboard. Lots of work went into this one due to various failed incorrect ignition components and ALL of the adjusting screws were incorrectly set.

[@jodady1234]

Great videos in this series. Good to see the approach from base level up, only checking things that are worthy of checking. Thank you!

[@mgarner79]

Thank you sir this is the second Mercury outboard you've helped me diagnose. My 1996 9.9 has the same symptoms you described after you reinstalled the factory stator. Weak/intermittent spark on the bottom cylinder. When I switched the wires to the coils the weak spark followed. Guess I'm gonna order a switch box

[@tedsmarinerepair8956]

Glad it helped and gets you back on the water quickly!

[@jamiemiller3004]

Thanks a lot Ted. Very, very helpful video.

[@throttleocean1586]

Awesome videos! Thanks for putting them together!

[@tedsmarinerepair8956]

Your welcome! Hope they help!

[@tjrpmw]

Thank you for sharing this 👊

[@zaneGoodwin]

Thank you for doing this video, you have helped me work out why motor wont start, it is the stator, the reading was so low on black/white wire 0.14 compared to yellow/black wire 3200+

[@tedsmarinerepair8956]

Glad it helped! And for the positive feedback! Happy Boating!!

[@alexemerenciana9875]

Hello, I watch your videos and I really like your advice. I have a question. I have a Mercury 25 HP start and rune for 3 minutes and then turn off. I clean the carburetor still the same. Someone looked at the engine and told me it was an electrical problem. Do you have some advice for me, where I should start looking?

[@barryotoole949]

I followed your guides and all checked ok but now I get full spark in one cylinder and on the other, it only sparks once then nothing. If I let it set for a few seconds it will repeat the single spark. I have replaced the trigger and the box and switched the coils but the issue remains. I am at a loss. Any ideas?

[@casper3130]

Man wish you were near my location I got a 1997 Suzuki DT115 driving me nuts. It use to run like a top but after sitting 4 years I did the routine of de-winterizing, new fuel, new fuel line, new battery and it'd turn over but not start. Primed it with a squirt of fuel in the silencer which I'd sometimes have to do at the start of the season and nothing. Checked for fire at the plugs and none of them are sparking. Checked my grounds, ran through all the wiring for corrosion, cleaned contact points on the pulse coils, battery coils, checked stator wires, used multimeter to check voltage, got voltage readings all the way to the CDI unit. making me think the problem is the CDI but, Decided to order the factory manual to be certain it was the CDI considering a new one is $2300 and found the Manual shows a Tester with a Test Cord sold separately for $500 to test the CDI but, that isn't the craziest thing, the model per motor serial plate shows the motor to be a 1997 and the Manual page which is model specific shows the 1997 having a ECU with a total different color coded wiring diagram not a CDI Unit with the wiring color codes my motor actually is wired. At that point I went to a Marina shop and he didn't know what to tell me and didn't want to work on it.

[@tedsmarinerepair8956]

my only comment would be did you check the emergency stop lanyard? I've seen that before.

[@casper3130]

@@tedsmarinerepair8956 Yep, the first things I checked where the kill and ignition switches. Re- reading the whole manual last night I found in Trouble Shooting it only shows if No Spark- Grounded or defective kill switch, Open Coil or Grounded Ignition Coil, Defective CDI Unit. Then in the back of the book under the ignition control system it reads w/o signal from the Gear Count Coil and Pulsar Coil the engine will crank but not start due to no fuel injection. Wonder if I read it again how much more hidden causes are in the manual. Gonna check those coils soon as I found out how and can go do it, just crazy.

[@adolfdrone2924]

​@@casper3130did you fix it!? Thanks.

[@casper3130]

@@adolfdrone2924 Negative, had to buy a DV adaptor for my multimeter in order to check all of the electrical parts because the manual reads you have to get the correct Direct Voltage to determine and because l have to have someone turn over the motor as l check, me and a buddy of mine haven't had a chance for time to get back to the lake property so, it sat this year.

[@adolfdrone2924]

@@casper3130 Good Luck☘️

[@kcpilotpat]

Well done this helped me a lot. Can you use an external power supply be run to the CDI to simulate the stator for trouble shooting? Please considering part 3 by installing a fulty trigger and showing us that diagnosis. Thanks Pat

[@tedsmarinerepair8956]

No I don't know of anyway that the power going into the CDI could be used for diagnosis of the system. I will put the Trigger fault testing video on my list! Thanks for the feedback.

[@TheSilverSurfisher]

Thanks for Posting the video(s) and love the cool equipment (measuring tools/meters, etc. presented). That being said, I wasn't even late for class here...I was early.....but perhaps I'm in the wrong class totally....please tell me what day you are covering material for the beginner-Intermediate class?!.....LOL!.......your terminology/jargon, the OEM factory values and settings chart, manufacturer's book/lesson plan...I got none of those school supplies or reference guide items for this ADVANCED class curriculum sir (they gave me obviously basic and limited different tools/measuring items/equipment). Nor do I know how to acquire such (or interpret it) at my current academic status. In spite of, I tried my best to follow along sir...and i was doing great...until the last 5/8 of this Part 2 video (I did repeat-watch parts I was confused about 4 times). I may actually need to seek remedial training again! Gosh Darn! 🤔 I.E.: Where and what brand is the analog voltmeter and is it Mercury engines specific? "Trigger"? (@ 8:50) What are we talking about exactly? Uh...Hunh?! (@ 7:30-10:30) More wide angle visual and explanatory details/instruction/information on the Switch box and Coil stuff (nevermind I'll research it up on remedial class videos) WTH?! (@ 11:49-12:40) More wide angle visual and explanatory details/instruction/information on Idle...mixture....RPM....WOT...Degrees Marking.... okay, hunh?!...oh, right...(nevermind I'll research it up on remedial class videos) Still Love and Appreciate the knowledge-sharing! 😉✊🙏

[@tyfab6288]

These are great series! I have a Mariner 9.9hp from 1997 that I got for free. It looks exactly the same as the this video. Previous owner says it does not run. It has an ignition issue apparently. (Waiting for fuel tank to arrive so can’t run it at the moment) It seems to have good spark on both cylinder and compression is even (100 both cylinder) I did Ohm test: Stator: black/yellow: 630 Black/white: 135 Trigger: 735 Readings are way below than spec from the book. I don’t know how to do a dva test to check the switch box but it looks like it is those CDI ones (not OEM) To me stator and trigger need to be replaced. Thoughts?

[@tedsmarinerepair8956]

If you have good spark to both cylinders then I would suspect a fuel issue. When you get the fuel tank see if it starts, if not try spraying a little carb cleaner in the carb and see if it fires and stalls. If so a fuel issue.

[@tyfab6288]

@@tedsmarinerepair8956 - ok awesome thanks! even if the Ohm reading are below specs? It has sparks on both cylinders by the look of it.

[@tyfab6288]

@@tedsmarinerepair8956 So I got the fuel tank and it still does not start, I put a bit of fuel into the cylinders and it backfires like a shotgun but still no start.

[@harrimoelands3653]

Hey, i have a 6hp mariner and was wondering where i could find that booklet or page you have to test all the wiring of the stator. Thanks

[@harrimoelands3653]

@Teds Marine Repair

[@tedsmarinerepair8956]

That info can be found in the service manual. You can likely download a version in pdf.

[@judzinh6651]

good afternoon ! I am your subscriber, I have a question for you! There are two Volvo Penta D4 300 engines on the boat, one of them does not rise more than 2600 rpm, there is a suspicion that the problem is in the fuel pump, the filters have all been changed! for each engine its own tank, they swapped the supply from the tanks!

[@judzinh6651]

you can send your answer to the mail [e-mail] or a video clip on this topic!

[@dannybrown8422]

Hey Ted I have a 50 horsepower Evinrude with no spark when the weather is cold but far's write-up when the weather warms up. Any ideas

[@tedsmarinerepair8956]

Power pack may be the issue. If no spark in both cylinders. I would test stator output as well.

[@dannybrown8422]

@@tedsmarinerepair8956 put a new power pack on it last year but I don't have a DVA to check the stator but the ohms checks out good. Thanks so much for the help

[@D3Watkins]

I think this is the issue with my 25hp merc. I was recently stranded for 3 hours on a lake due to this 😅

[@thomasmiller1302]

I have a 60hp mercury that's not firing on one cylinder help me

[@makesaracu1264]

Salutare am și eu o problema la acest motor care ar fi motivul de îmi dă scânteie doar la o singura bujie ambele bobine care vin conectate la bujii sunt funcționale oare sa fie de la cdi sau la platou de sub volanta mă puteți ajuta cu un sfat că am reușit să îl pornesc pentru o perioadă de 30 secunde dar pe urmă a început să întrerupă și sa oprit și acu nu mai dă iar la ambele bujii mulțumesc

[@tedsmarinerepair8956]

Pentru un motor exterior în doi timpi, ai verificat compresia? Puteți încerca să comutați bobinele de aprindere de sus în jos. De asemenea, puteți încerca să comutați bujiile de sus în jos vezi dacă pierderea scânteii sare la celălalt cilindru. Sper că acest lucru vă ajută! Ted

[@makesaracu1264]

@@tedsmarinerepair8956 salutare cred al meu motor 15 cai 2 timpi Mariner Mercuri . Cred că cdi nu mai lucrează bine Am verificat firele care vin din motor și lucrează toate din platou și cele de pe al doilea platou care ar fi avansul la accelerație 1 din platou ies 3 fire de culoare 1 alb cu negru 2 galben cu negru 3 masa negru Și din platou de la avansul de accelerație sunt 2 fire 1 maro cu alb 2 maro cu galben Astea sunt verificate cu aparatul de măsurat Și din cdi sunt 8 fire care ies 4 din iele se împerechează cu cele 2 de la platou și cu cele 2 de la avans și din cdi mai ies 2 de culoare verde cu alb și verde cu galben care duc la bobinele de la bujii și încă unu masa și unu de taie scânteia Problema vine de la unu din cele 2 care vine la bobina bujie nu iese curent am pus între iele și celălalt dă scânteie și la bobina stânga și cea din dreapta deci bobine in regula In momentul când decuplez firul de culoare galben cu negru care se mireasa cu cel din cdi nu mai am scânteie nici la cea langa bujie pe când cel cu alb cu negru la ieșire platou are curent și la ieșire cdi nu are așa că o parte din cdi stricat cred

[@WIlliamMcHugh-fq2ds]

Coils .9 Stator 2800 Spec 750-1400 Trigger 722 Spec 800-1100 Mercury 20hp 1987 No spark on one cylinder Any advice?

[@tedsmarinerepair8956]

What is the secondary resistance of the ignition coil? Might be a switch box or a coil.

[@michaellynnes7388]

You went all the way through but never showed us what and where the switch box was.

[@tedsmarinerepair8956]

Sorry about that! If you look at 3:15 of the video the switch box it the black box on the bottom right of the engine. I will have to try to modify it. I Guess a video on the location of ignition components on small outboards is one I should do.

[@territodude]

Hey Ted how about getting yourself a mic, can't hear you half the time.

[@djmjr77]

I heard him fine...