3.7l to many volts to coil???

[AKFISHRIPPER]

So I've been having a lot of issues with my mercruiser 170 from the day I bought it, I got all the fuel issues figured out and now I have a problem with my coil. At first the motor would only fire when I was cranking it over then die so I was pointed to the slave solenoid which I replaced and now the motor starts but my coil is getting really hot. From what I heard the coil is only supposed to be getting 8 volts and mine is getting a full 12.5??? Any help would be awesome, is it maybe possible that I bought a bad part or maybe a ground out wire? I've measured all the connections with a multimeter and the one with the purple wire reads anywhere from 15-140 volts when the key is in the on position but not running.

 

[stonyloam]

Re: 3.7l to many volts to coil???

First off the symptoms described (only firing when starting) is a symptom of having a bad connection on the resistance wire from the choke rather than a bad slave. The coil gets voltage directly from the slave during starting, so it would seem that was working properly. While the engine is running your coil + gets its voltage from the purple resistance wire attached to the choke connector. Sounds like it is time for a new multimeter, you can't get more than battery voltage at the coil with the engine not running. Check the battery voltage and the coil voltage with the engine running. If the battery voltage is higher than about 14, then you probably have a failing voltage regulator (if you have the original) and it is time for a alternator conversion. So double check your voltages, a fully charged battery with the engine off should read 12.6 volts, with the engine running should be about 14, and coil voltage should be about 8 when running. The resistance wire should read 1.8 to 2.0 ohms. Good luck.

 

[AKFISHRIPPER]

Re: 3.7l to many volts to coil???

I just got a new resistance wire today so I'll try that, I already replaced the slave solenoid and the old wire dies look like its been messed with in the past. I'll fire it up today and check to voltage at the coil again and repost my findings.

 

[AKFISHRIPPER]

Re: 3.7l to many volts to coil???

The resistance wire fixed the ignition problem but after running the boat for 30 minutes at 3000 RPM it bogged out and died. I had started a previous tread about this issue and never really got it narrowed down. I have replaced everything short of the voltage regulator...???????? I can run the boat at about 1500-2000 rpm all day but as soon as I run it at or above 3000 for 30 minutes or so it will continuously bog out and die.

 

[fmalott]

Re: 3.7l to many volts to coil???

The resistance wire fixed the ignition problem but after running the boat for 30 minutes at 3000 RPM it bogged out and died. I had started a previous tread about this issue and never really got it narrowed down. I have replaced everything short of the voltage regulator...???????? I can run the boat at about 1500-2000 rpm all day but as soon as I run it at or above 3000 for 30 minutes or so it will continuously bog out and die.

you can replace every elecrical part a hundred times and if your voltage regulator is over charging it will fry everything a hundred times i'm pretty sure this was mentioned on your other post. before you do anything you need to test the voltage regulator and if it's under charging or over charging you need to convert to a alternator and then start testing other electrical parts to see what damage was done with the old charging system

 

[stonyloam]

Re: 3.7l to many volts to coil???

Famalott +1, What is your battery voltage with the engine running (about 1500 rpm)?

 

[AKFISHRIPPER]

Re: 3.7l to many volts to coil???

Famalott +1, What is your battery voltage with the engine running (about 1500 rpm)?

I got tried of dealing with it so I dropped the boat off at the shop yesterday, so I'll let them deal with it now.

 

[stonyloam]

Re: 3.7l to many volts to coil???

Whatever you do DO NOT let them sell you a new voltage regulator! The part alone is $500+ and it will eventually fail. You can get a nice alternator conversion from Breezworks for about $300. Good luck

 

[AKFISHRIPPER]

Re: 3.7l to many volts to coil???

Whatever you do DO NOT let them sell you a new voltage regulator! The part alone is $500+ and it will eventually fail. You can get a nice alternator conversion from Breezworks for about $300. Good luck

Thanks a lot for the heads up, I might just do that either way so I don't have to worry about that in the future. Also I was wonering if I should just do a electronic ignition conversion at my next tune up as well, I've heard a lot of people like them and some swear by points?

 

[nola mike]

Re: 3.7l to many volts to coil???

Thanks a lot for the heads up, I might just do that either way so I don't have to worry about that in the future. Also I was wonering if I should just do a electronic ignition conversion at my next tune up as well, I've heard a lot of people like them and some swear by points?

I don't think anyone swears by points, though they do the job. The electronic conversions are a lot more reliable with a lot less adjustment.

 

[fmalott]

Re: 3.7l to many volts to coil???

i did the electronic conversion on my 470 so far so good but remember anything can break down so saying that keep your points handy just in case

 

[stonyloam]

Re: 3.7l to many volts to coil???

Thanks a lot for the heads up, I might just do that either way so I don't have to worry about that in the future. Also I was wonering if I should just do a electronic ignition conversion at my next tune up as well, I've heard a lot of people like them and some swear by points?

I do like my petronix. I just wrote this in another thread the other day, so I just copied it in:

FYI I have the same engine. Mine is a Petronix Ignitor II (91146A $115) with a Flamethrower II coil (45111 epoxy $47) the oil filled would also work (45011). Would recommend getting both the Ignitor II and coil. If you go with the Petronix and flamethrower you will need a full 12V to make it work properly, so on instillation remove the purple resistance (you don't have to cut it off, just tape it off out of the way) wire from the coil + and splice a stranded wire into the purple wire going to the choke (I used solder and a couple of coats of liquid tape), run that wire to the coil +, that will give a full 12V for the Petronix red wire.

 

[nola mike]

Re: 3.7l to many volts to coil???

I do like my petronix. I just wrote this in another thread the other day, so I just copied it in:

FYI I have the same engine. Mine is a Petronix Ignitor II (91146A $115) with a Flamethrower II coil (45111 epoxy $47) the oil filled would also work (45011). Would recommend getting both the Ignitor II and coil. If you go with the Petronix and flamethrower you will need a full 12V to make it work properly, so on instillation remove the purple resistance (you don't have to cut it off, just tape it off out of the way) wire from the coil + and splice a stranded wire into the purple wire going to the choke (I used solder and a couple of coats of liquid tape), run that wire to the coil +, that will give a full 12V for the Petronix red wire.

I went with $99 option, which is working well on it's third season. Doesn't require coil replacement or new wiring.
Mallory Electronic Conversion Kit 9-26900

 

[AKFISHRIPPER]

Re: 3.7l to many volts to coil???

I went with $99 option, which is working well on it's third season. Doesn't require coil replacement or new wiring.
Mallory Electronic Conversion Kit 9-26900

I looked at that online, so I can keep the same coil I have now and keep the resistor wire hooked up?

 

[nola mike]

Re: 3.7l to many volts to coil???

I looked at that online, so I can keep the same coil I have now and keep the resistor wire hooked up?

correct.

 

[stonyloam]

Re: 3.7l to many volts to coil???

As I understand it if you leave the ignition on with the Ignitor II there will be no impact, but the original Ignitor does not have this protection. I would suggest that you go with the Ignitor II. Very important note: If you keep your original coil you will still have to run the red wire of the module to a full 12V source. My suggestion would be to splice into the purple choke wire as described before, so you still have to do some rewiring. IMHO if you are going to upgrade, do both the Flamethrower II (45,000v vs stock 20,000v) and Ignitor II. Good luck.

Oops, I see Mike went with the Mallory kit, I do not know if that is the same as the Petronix, as far as voltage requirements go, sorry.

 

[nola mike]

Re: 3.7l to many volts to coil???

Oops, I see Mike went with the Mallory kit, I do not know if that is the same as the Petronix, as far as voltage requirements go, sorry.

No, different. Mallory kit requires decreased voltage, same as the points.

 

[AKFISHRIPPER]

Re: 3.7l to many volts to coil???

Good info guys, I still have not heard anything from the repair shop because there backed up around here but I'm going to go ahead and order the alternator kit and ignition kits.

 

[fmalott]

Re: 3.7l to many volts to coil???

Good info guys, I still have not heard anything from the repair shop because there backed up around here but I'm going to go ahead and order the alternator kit and ignition kits.

to me it's sounds like from your other threads you can do this your self get the boat back and do it your self i did the alternator and ignition conversions myself and it was very easy and i'm not a mechanic

 

[AKFISHRIPPER]

Re: 3.7l to many volts to coil???

to me it's sounds like from your other threads you can do this your self get the boat back and do it your self i did the alternator and ignition conversions myself and it was very easy and i'm not a mechanic

Yea I'm actually a jet aircraft mechanic but when it comes to an issue like this I'm at a loss because they have different operating systems but for sure I can install an alternator and ignition system