750K2 Coils

[philward]

My standard K2's leads are knackered and as they are the original 40 odd year old coils am looking to buy a new set - are these KOKUSAN do you think - they have same part number on box as OEM

https://www.ebay.co.uk/itm/New-Ignition-Coil-69-78-CB-750-Hondamatic-Super-Sport-K-A-F-Coils-Spark-Set-W258/232799393802?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

[Bryanj]

They are obviously pattern as both points wires are yellow but do come with brackets. Dont forget you MAY get charged 3% import tax then 20% vat on total of cost+postage+import tax then £11 to the post office for the privelage of collecting the fee to pass on to HMRC!!!!!!

[neat street]

If its the HT leads that are no good, check Ashes info on repair/replacement, works a treat :-)
John

[firet49]

I have a set of Accel coils for a cb750 bought them on here a while ago still sitting on the shelf.
If would sell them on if they are of any use to you.
Thanks

[philward]

I have a set of Accel coils for a cb750 bought them on here a while ago still sitting on the shelf.
If would sell them on if they are of any use to you.
Thanks

Thanks for the offer but I'm looking for some new standard or repo looking coils (as my K2 is in standard trim
Thanks anyway

[firet49]

No problem hope you get sorted

[Rob62]

I used wemoto coils on my build. They are very reasonably priced, look good and work perfectly. Maybe not for the show winning purist but perfect for anybody else.

[philward]

Just bought these

https://www.ebay.co.uk/itm/Honda-CB-750-K2-S-O-H-C-1974-Replacement-Ignition-Coil/263456145722?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Done a lot of umming and erring then thought sod it, cant see them and only poodle around on the bike so why pay silly money
I'll do a refurb on the original coils as per Ash's guide (at some point!)

[Rob62]

They’ll be much better than the originals.... nice one

[philward]

Bit of feedback on the m&p coils. They dont bolt straight on - you will need to file the rear alloy bracket to accommodate the coils electrical spade fitting - otherwise they foul and could short. Also, the male and female bullet connectors are the wrong way round to fit to the loom bullets
On the plus side, the bike appears to run smoother than with the 40 odd yer old coils.

[AshimotoK0]

All I can say about pattern coils is check their primary resistance. Honda ones are around 4.5 Ohms. Some pattern ones are 3 Ohms' ish and this puts a lot more current through the standard points than they were designed for. If fitting CDi then that's another matter and a 3 Ohm coil will probably be fine. The other thing about the low resistance coils is that with the ignition switched on but without the engine running, the contact breaker that is in it's closed position will cause the coil to consume 48 Watts, so will overheat rapidly.

If I recall correctly there is a horror picture in Hondaman's book on the CB750 of the results of using low resistance pattern coils with standard points.

[philward]

Thanks for that Ash! that will worry me to death! seriously, how do I check the primary resistance and if they are 3 ohms, can the circuit be modified to alter the resistance (I'm no electrician but putting a resister 'inline' externally).

[AshimotoK0]

Thanks for that Ash! that will worry me to death! seriously, how do I check the primary resistance and if they are 3 ohms, can the circuit be modified to alter the resistance (I'm no electrician but putting a resister 'inline' externally).

Don't have sleepless night as they say on Crimewatch  . You can check the primary resistance with a decent multimeter on Ohms resistance range ... or put a meter set to 10A current range in series with the coil and it should draw no more than 3.5 A Plus some aftermarket coils will be absolutely fine. You could put a resistor in series of say 1.5 Ohms but that would reduce the HT. However they may still be enough energy to give a decent spark.

[philward]

Thanks Ash - I'll have a go later if the grandkids will let me!

[philward]

Just checked coils Ash - 4.2 Ohms, so I guess  that's close enough. (4.9 Ohms on old coils)