Ignition coil help/advice...

[carguy5387]

Sooo, I have a 73 cb175. The stock ignition coil seems to be for little girls (no offence if you are a little girl). Also, the spark plug wires are integrated into the coil. My coil is old and busted, and I would like to run some pretty cloth wrapped plug wires. So here's my question...

What aftermarket or other factory ignitions coils would work on my bike?

I have heard that a XS650 coil works fine...


Any thoughts?

Thanks a bunch!

 

[teddpage]

you can hit up mikesxs.com for replacement coils. he has a few to choose from.
dyna ignition coils are also nice, but a little more pricey.
if you go with an aftermarket coil, you will have to either buy a pre-made ignition wire set or make your own.

 

[carguy5387]

thanks! thats a great website, tons of hard to find stuff for a xs650. Does anyone know of a webstore like that for Hondas?

 

[bjbuchanan]

get a universal one off of DCC and hack the stock wires off your stock coils. make little jumper leads by adding connectors on to them.( retains harness originality.)

hit up autozone for a set of accel super stock wires because they are copper core and no resistance and throw on a set of the plug caps

the wires are like 22$ and are good for like 4 to 5 bikes

 

[carguy5387]

welp, I went the the dcc coil, and some yellow cloth wraped plug wires. I'll be putting those gems on soon!

 

[Speedshop]

Oh when will people wake up to the fact that dyna coils are rubbish! I must have thrown out a quarter of a ton of failed dyna rubbish over the last 2 years compared to a shoe box of OEM coils that have failed. We have a testing shop for electrical parts so we get sent a lot of ignition systems for checking!

The XS coil is very weak, a quick read on the XS650 forum will confirm this too. The problem is finding something that fits!

Rule of thumb with coils, avoid Chinese (IE cheap eBay) as they seem to be in competition with dyna to see who can make the most rubbish.

Good coils are not expensive and ones made in Tiawan or Japan are usually the best.

 

[hillsy]

Not all coils are the same - you want to get a coil with the same ohm rating as what you currently have.

 

[Speedshop]

Yes and no.

Thats a good guide, however you will not get a 1 ohm/12K ohm cdi coil these days. This was popular on many 1970s bikes with CDi. The popular replacement is a 0.6R/6K.

I design and build ignition modules and have thoroughly tested out many combinations of coil and igition over the years. What is more important then the resistance is that you get the correct type of coil. Most coils are divided in to CDi type, transistor ignition type, battery pionts and AC (magneto) points. So long as you get a coil that was intended for the type of system you have you won't go far wrong, even if the resistance is not right.

You can swap AC magneto ciols with CDi on basic systems. A Battery points coil will work on Transistor ignition but its not optimum to do this - in theory you can damage the coil driver but in practice these are well protected and very tough little transistors

What you must not do is wire a battery points coil to an AC CDi - the reactance of the coil is sufficent to form a tuned circuit with the capacitor in the Cdi box in some cases. Even if this does not happen, as the revs pick up the spark intensity dies down as the coil can not cope with the 200 volt punches the Cdi unit kicks out. A coil will resist a change in voltage (which is why the points arc when they open) and the high voltage spikes result in the coil strongly resisting them!

This is just one of the Cdi units we make - its for the Classic Yamaha TZ racing bike - its a high power high accurracy CDi unit - and yes we do stock the correct coil for it!

 

[Bobby Joe]

Oh when will people wake up to the fact that dyna coils are rubbish! I must have thrown out a quarter of a ton of failed dyna rubbish over the last 2 years compared to a shoe box of OEM coils that have failed. We have a testing shop for electrical parts so we get sent a lot of ignition systems for checking!

The XS coil is very weak, a quick read on the XS650 forum will confirm this too. The problem is finding something that fits!

Rule of thumb with coils, avoid Chinese (IE cheap eBay) as they seem to be in competition with dyna to see who can make the most rubbish. KilO

Good coils are not expensive and ones made in Tiawan or Japan are usually the best.

First off, thanks for the great information. So what brand, generic or not, would you suggest for our early 70's Hondas? I have been having trouble finding many 4.5-5.5 ohm, dual output coils, and without your extensive knowledge, most sites don't seem to provide enough info to make an educated choice.