3.0 mercruiser ignition diagnosis and repair

[austinking]

I was having the exact same issue recently... so i started with what i thought was the obvious solution, tue fuel system. I rebuilt the carburetor, swapped out the old mechanic driven fuel pump for electric and the damn thing just simply wont start. Now im getting fuel and possibly too much at 4-7 psi, enough that my plugs smell like gas anyways. I just put new plugs in but it just wont bust off. This video helped my find a new rabbitt hole to try so thanks for the post and ill give it a check.

[woodystreeservicePNW]

Thank you! I'm currently fighting a 3.7l mercruiser 165hp it has no spark. I still can't get it to run 😅 but I appreciate all these videos you never know what little peice of information you might hear and all the sudden you figure out what's wrong. 😊

[clunkerrevival]

Hey bud thanks so much for the great video you help me, my boat, and my channel out!

[misskittynpitters]

Hey thanks a lot I've been chasing my ass around trying to figer out the same issue and I think your video shed some light for me 👍🇨🇦

[barrybebenek]

Nice catch on the coil fault. Saving this one in my vault for future trouble shooting. 🇨🇦👍🏼

[eriklindskog]

It happened to me as well about two months ago. Itermittent  ignition coil problem with my Mercruiser 3.0. The engine could run fine for one hour and then suddenly die a few seconds, run-die run-die-etc and then run again for a long time. I thought I had a fuel pump issue. The fuel pump was not good but that was not the culprit. I spent a lot of time on it and I finally had to get help from a professional mecanic to find the real problem. I have now learned that you can find an itermttent ignition problem by connecting a timing light to the engine. If you look straight in to the light when the problem occurs you can see if the flash is regular following the rpm or if it is irregular. If it is irregular you have an issue with the ignition but if it is regular you have some kind of issue with the fuel system.

[steveskinner]

Thanks for doing the research… I believe I’m having the same issue…. First I thought it was fuel filters, changed both… no change, now I’m thinking it’s coil… going to follow your advice/steps and fingers crossed, it’s the issue!? After all it’s a basic simple bulletproof motor… right?but it’s a boat!
Thanks again 👍

[RyanSandbergInc]

I never thought Philip Seymour Hoffman would help me fix my boat.

[slideglide]

Just a
Replace the alternator for a 1 wire marine SsAEJ1171.
Replace coil with an internally regulated 12v model.
Run a keyed 12v source to the + coil post.
Remove the resistor wire.

[BLKDIENOMITE]

Can you post a video of where the wires that are connected to the coil lead? Mine got cut and I can’t figure out where it leads to

[williamhunter]

Nice video! What is the name of the part you had to change? My 3.0 won't start so I'm thinking my plugs are bad as my battery is good. Haven't changed plugs in 3 years so I'm thinking thats the issue may change the wires as well.

[juanhr]

How would you close and open the points?

[jagemc]

Having the same issues going to pick one up tomorrow for $20 hope they fixes my issue seem to have the same issues!!!

[JEHERETIC]

Thank you for this video, I didn't know that the points shut power of, I'm not that old school to know that

[TheMcs]

how do you know when your motor is getting hot I just got that same order you have but I don't have a temperature gauge and he said the oil is coming out the manifold out the little holes on top is that true

[angelcitytowing]

Do you know if this thing has an internal voltage regulator in the alternator or is it external somewhere on the boat?

[ActsofRandom]

Did you buy any coil from like auto zone. I got a 3.0l OMC with no spark and im trying to find a new replacement coil!!

[shaunsmith]

I just had a coil problem and had it fixed. Mercruiser 3.7

[karljoppasjr]

So you said it ran fine some times and not others..would it go slowly but when you hit the throttle would it die/stall?

[tylercurtis]

i had this problem only i had a crack in the top and it was causing it to short out my coil. i worked and worked until dark and kept going. would run idle not go past 2, 500 rpms. acted like key off untill i throttled down. by working my ASS off tyring to figure this out so i could go boating w the fam, and it being dark i saw the spark and found the crack, new coil on the way be here before friday YAY beer and the lake this weekend!!!!