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Mercruiser 470 pertronix wiring question

I have not replaced the fuel filter since I started with this motor 3 seasons ago. Thanks for the reminder, I will change. So I have a resisted power wire going to my internally resisted coil. This is what I suspected may be giving me grief. I want to piggy back the purple wire going to the choke and extend it to the coil+ then remove the resisted (brownish redish purple) alltogether. The exposed wire you speak of, is that on the coil? If it is, its from the pertronix unit (red & black), see in the coil in the first picture where joe pro mechanic crimped yellow spades to the wires.
 
What I mean by the exposed wire is the brownish purpleish redish wire...........This wire is what is suposed to be the resistor wire. It is also suposed to be wrapped into the harness but you said it is completely visable.........(exposed)

Disconnect it from the coil, pull the connector off the choke, connect your ohm meter between the choke connector you pull off and the end that was connected to the coil +

Do not do anything else until you confirm that wire is 2 ohms......

I am not suggesting this is your problem, I am only making sure you have your igniton system wired and running correctly.

A clogged fuel filter could be your root cause...........a glogged vent line from the tank could be also.

We do not know what is not happening after your 45 minute issue occurs. If it happens again we need to do certain checks as I said in an earlier post.

ONE THING AT A TIME!!!!!!!!!!!!
 
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Thanks Kghost, I am clear, I'll get the ohm measurement on that wire before I do anything. BTW, when I fill my tank at the pump the vent usually shoots out a stream of gas before the pumps automatically shuts off, so the vent is clear.
 
The results are in! Well not really,I did not want to remove the brownish purple wire from the system because I want to run with a stock coil first before I butcher the wires - sorry no ohm reading. Next test was the voltage at the coil (while running) here are the numbers..........14,6,10,3,12,7,9,11,8,5, everytime I held the volt meter on a good ground and the coil+ the numbers were very sporadic, it just hovered on 10 volts for a couple of seconds must mostly all over the place. I am having trouble locally to find a replacement stock coil so I may have to order one online. If anyone knows and part number for a auto coil that would match up with the mercruiser one please let me know. I did find a mystery green wire going from the wiring harness down below the motor, I got a picture but I was having more than one electrical problem last night because the power went out at 6:00PM until 9:30PM and I wasn't able to upload the picture. I will report back when I test run a stock coil.
 
Look here Item 31, Sierra part is only $34,00

http://www.marineengine.com/parts/m...9801982/5520115-thru-6218036/distributor-coil

Also disconnect the tach lead and retest!!!! the voltage should be steady.....

Remember that if the wire from the choke to the coil+ is not a resistor wire than the coil you have now will work fine!!

We are just trying to confirm what that wire is.

Use the battery ground post/terminal as a ground point for your meter lead,
 
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Yes, I forgot to disconnect the tach wire when I tested last. Well I just tested with the tach off - steady at 10 volts. So I guess I'll order the stock coil and give it run. I did a compression test when I first got the boat and it was 140 psi all across except #4 was 120 psi. Voltage at the battery was the same on the dash - 13.8 volts. Thanks for the help determining the coil voltage!
Team
 
You have not confirmed if the wire from the choke to the coil is a resistor wire or not?????????????????????

Without knowing this dont spend mony on a coil you may NOT need.......

Again, If the wire is just a wire and NOT the reisistor wire then the flamethrower coil will be fine to use.

If it is a resistor wire THEN buy a new NON internal resistor coil

If the tach was causing bad voltage readings I would retest boat and see if the problem you are having goes away without the tach lead connected at all.
If it does work ok with the tachometer disconnected, Buy a new Tach........
 
I am pretty sure it is the resistor wire because it is factory terminated at both ends. Tonight I will cut both ends off the wire check the resistance with my volt meter. If it does have resistance I will wire a new (regular copper) wire between the choke & the coil+. No need to buy new coil:). I hope a regular 1/4" crimp on style spade connector will fit on the choke because I will have to cut off the factory clip that goes into the choke (see previous posted picture) and I know I won't be able to replace it. I will be checking with the tach connected and remove the tach if the problem arises - thanks for this information I would have never considered it. Report to follow.
Team
 
I cut out the brownish purple wire, it was a silver almost solid wire, I couldn't get an ohm reading from it. I then ran a wire from the choke to the positive coil and test fired. It was always hard starting but not now - it fired up right away with authority. Thanks for all the guidance and showing me around my electrical system. It important to be familiar with all the operations of the drive-train in an emergency. I plan on a long run this weekend, I hope I don't have to reply again to this thread!
 
Teamcrush said:
I cut out the brownish purple wire, it was a silver almost solid wire, I couldn't get an ohm reading from it. I then ran a wire from the choke to the positive coil and test fired. It was always hard starting but not now - it fired up right away with authority. Thanks for all the guidance and showing me around my electrical system. It important to be familiar with all the operations of the drive-train in an emergency. I plan on a long run this weekend, I hope I don't have to reply again to this thread!
Click to expand...

As I said, The resistor wire is not a coppper standed core. It is a solid type wire as you found. That is a resistor wire!!

Now that you have run a normal nonresistor wire the coil is getting full voltage as intended.

Also as asked did you have the tachometer connected?

No need for a new coil...........
 
I had the boat out yesterday, runs awesome, put about 2 hours on the meter with no concerns. I ran with with the tach wired in, all gauges work as intended. I did have the timing set up before the pertronix was installed because it had a bad case of pre-detonation. Runs and idleds good at 6 degrees BTDC. Yesterday, I noticed I was able to achieve WOT doing 32 knots @4400 rpm, I could never achieve this before. I did happen to hear an on again off again drone type sound only when I was trimmed up, if I trimmed down a bit the sound would go away. I suspect gimble bearing? My gimble bearing is on its third season, is this normal to make this sound? I just greased it last week.
 
Good job!!

Timing is correct for that motor and as far as the noise goes...maybe check the ujoints for grease/wear and it never hurts to double check the gimble bearing.

Typically a gimbal bearing makes noise when turning left or right and it is a growling sound...not so typical is it when trimming up.

But not impossible......if and when you remove the drive, stick two fingers into the bearing, if it is not smooth as silk with only grease as the friction then replace it. All new bearings are NON serviceable...no more greasing them. One time install....
 
Thanks kimcrwbr1 & kghost for sharing your (dual)wisdom to get me through the correct troubleshooting procedures and ultimate repair! I also appreciate the prompt responses to my request for assistance! Respect
Team
 
Great post guys! Love it when the poster follows advice and shares the results all the way through!
Im a "shade tree DIYer mechanic". And have learned a ton here by reading posts just like this one.

Kgohst even offered to call me once. I took him up on his offer and got the issue resolved.

if your out drive is upside down facing the opposite direction on a bench and your turning it counterclockwise ( as instructed) your actually turning it the wrong direction!
 
Nice job explaining the electrical issue, I experienced the same resistor wire issue when PerTronix ignition installed. Mine is also fixed.
 
Hello

So I just ran a Jump wire from the chock to the + terminal on the pertronix coil. Is this sufficient and should I cut the Purple resistance line that I left connected to the + terminal.

Thank you
 
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