Ignition coil replacements.

[Polymer-2]

Here are some automotive ignition coils that can be adapted to the 750/900/1100. You will need to make a mounting bracket but that isn't much of a job and replace the plug wires. You will need 2 just like you have now.
Notice the price difference. These are all the same coils.

Autozone
Duralast C849   $27.99

Advance Auto Parts
AC Delco D555 $55.99
BWD E51Z $24.49
BWD Premium E51 $30.49

Napa
Echlin  ECHIC39    $61.49
DEMGN10123   $56.49

O'Rielly  Master Pro E51  $19.99

[woodsrider250-2]

Sweet, how do you like them?  Anything's better than stock!

[DrewArit]

thanks for this post... all the coils i've seen for the 750 are like 200+

[Polymer-2]

These are actually for a late model (2000 or so) cavalier 2.4L if I remember correctly.
I picked up a used pair at a local salvage for 5 bucks. I haven't tried them yet but a mechanic told me about them.

[caferacer1]

no way !!!!! now he tells me...lol

[unclehowlie]

Have you put them on yet? Can you post pics of the modifications necessary?

Thanks!

[Polymer-2]

Here is a link to the entire article. It replaces the stock ignitors, coils and spark plug wires with readily available GM parts. I got 2 coils with the plug wires and 2 HEI modules at a salvage for less than $20.00.
Also any GM I-4 or V-6 with coils that look like the ones pictured above will work. The 4 cylinder coils will even be labeled properly. On the v-6 coils just ignore the labels.
HEI - Waste spark Conversion

Note: The ignitors have to be replaced with the HEI modules because they just can't handle the current of the .5 ohm coils.

You did not tell us the ohms rating of any of the coils.
That is important. Or type of plug wires to be used with points or electronic ignition with these coils.

[sgtslag]

I've read about these coil conversions before, on another forum for Honda CB's.  They will put out a consistently high-powered spark, whereas the OEM coils are weak, and put out a poor spark.  Having said that, though, NGK Iridium Spark Plugs, at ~$8 each, will transform your ignition system, only requiring you to change the plugs, not the wires, or the coils, or the points system.

My '79 has a more advanced, almost CDI ignition system.  I replaced the standard plugs with NGK Iridium's, and when I hit the starter button, it was running instantly -- I literally jumped, it startled me so much.  Normally, I had to grind the starter for 4-6 seconds, twice, for it to catch.  The coils can work, but the Iridium Spark Plugs are easier to install.  They should last 50,000+ miles, as well, in your bike (they will last 100,000 miles in a car...).  Cheers!

[shinyribs]

My bike has stock coils and wires(who knows how old) and NGK plugs,but it does have a Martek 440 electronic ignition.Had been parked since 2004.Cleaned the carbs 1 month ago when i got it and hit the button...vrooom!Didnt even change the plugs.Once i synced the carbs it runs great.When cold it fires first kick every time.When warm i crank it by hand,again,first push every time. My Dad had 4 of these bikes new off the showroom floor(sorry rascal shoulda kept one)and put over 100,00 miles on more than one of them.I don't think the stock setup could be too awfully bad,but upgrades are always good.I'm not gonna change any of my ignition system,but i would love to know what the part number is for the iridium plugs if you can get it easily.Thanks   Eric

[TOOLS1]

DR8EIX http://cgi.ebay.com/ebaymotors/NGK-Spark-Plug-75-81-Honda-CB750F-Platinum-Iridium-NEW-/160642184665?pt=Motorcycles_Parts_Accessories&hash=item25670535d9
This coil, and ignition module replacement is meant, for the DOHC bikes  with the electronic ignition. It can be done to the older point ignitions using the points as a trigger, but, for whats involved I would just get a Pamco ignition.
TOOLS

[sgtslag]

It is less money to buy them at your local auto supply store since you won't need to pay S/H fees (shop price is very close).  

These plugs made an amazing difference on my 750.  I put them into my Voyager (not the same P/N, of course....), as well, but that bike has a really strong ignition system, so it made no noticeable difference.  Still, it means I won't need to change out the plugs on that bike for a number of years to come.  It also gives me a little piece of mind knowing that they are some of the best, and most reliable.  That helps when we're riding two-up, 500+ miles from home, with only a debit card as security.  Cheers!

[Piute]

 Hey Chromeribs did find this sight for some NGK's,
Didn't check there rep.suggest you check experiences


http://www.louis.de/_307d2cac2e9c2bdc756570f6cd13b59aae/index.php#artikelliste
stk # 10035111
SPARK PLUG NGK IRIDIUM IX
DR8EIX HONDA CB 750 K0-6 (CB750K0-6)    
 14.95 (18.

[Matt Story]

Reviving the dead here...

So, I suspect I have a stock coil or possibly a wire connection going bad '77 CB750F.  Timing chain, timing (points), valves and carb all set to the best of my capability.  I still am getting intermittent backfires from 1 & 4 at idle.  I intend to test the coil to verify the culprit.  Can someone point me to a test procedure?

If I wanted to run these automotive coils which I think run around .5ohm primary, could I get good results by placing a 4.5ohm, 50watt in series to each coil?  That would total the right primary resistance.  I don't know what effect it would have on the output.  Perhaps I could compromise to 3.5-4.0ohm resistors.  My concern here not to degrade the points too quickly.  If I were to upgrade to a Pamco or Dyna later I could either remove the resistors or change them to a lesser value.

Just thinking now, my best way out w/o spending alot is probably to pick up a used 1-4 coil....

Matt