Topic: Coil replacement options: CB750

[Tugboat]

Looking to finally track down the source of my CB750's bogging-down when it gets wet. So far it's been impossible to replicate at idle - evidently it must be under load for the problem to manifest itself. To that end, I'm thinking about replacing my coils, since they are one of the only parts that are (somewhat) exposed to water when riding in the rain.

Would you: (a) get some used (but "tested good") off ebay for $30, or (b) get some new from Honda @ ~$180, or (c) get some Dyna coils @ ~$150 (plus wires) and have to make some brackets for 'em?

[strynboen]

i have thanged the thik vires on mine coils..cut inn to the copper brik and veld a new vire on..
its importment not to cut the hole vay in from the front(vire inn side)...but only cut inn /down...hvere the veld must be done...then the vire are fixed..and the hole are easy to glue..

i have got some problems vith aftermarked coils..who spaked all over in wet veather...so did the old good again...

klik on photo..to get it a bit bigger

[flybox1]

You sure your cork seal at the points cover isnt letting water in? 
A member here makes a great, reusable neoprene gasket just for this.

Are the coils really bad, or just the wires/caps?
NGK splice kit and new wires/caps might be worth looking into.

[Tugboat]

Caps are new NGK, and I've already installed the neoprene gasket at the points cover.. that didn't fix it. Also, is replacing them with DOHC 750 coils an option?

[strynboen]

the dohs are eating more amps..=lower ohm...but they work for some..they are spec for elektronic ignision..who takes more power

[flybox1]

test your coils

http://forums.sohc4.net/index.php?topic=60263.0;nowap

[DH]

Lightly "mist" the coils and wires with an old windex bottle full of water.
If it gets worse with that, mist a little more and note how it acts. Do the same on the points cover to try and mimmic the problem. (if all else fails)

[CoachDoc]

Go for the new Dyna coils. They are excellent and reliable performers, and of course you can easily replace your leads in the future if needed.

[Mr Freeze]

It's not that used Honda coils are bad, but they are going to be 35-40 years old at this point. I sprung for the 5 ohm Dyna Coils and haven't looked back since. I got the set from Z1 Enterprises. You have to terminate the spark plug cables yourself for the lengths you need. Make sure you have a crimp tool or buy the recommended one that Z1 sells.

Once you do that, screw your spark plug caps on and ride on. I'd also put an ohm meter on my spark plug caps to make sure they are 5K ohms like they are supposed to be. If not, might as well replace those too.

[heyitsrama]

make sure you get the correct ohm for the bike if you go DYNA. I like DYNA because you can replace the coils, but then again don't listen to me because my bikes been on "build" for 2 years.

I created the same resistor setup that HondaMan sells on his website, because my ebay seller sent me the wrong ones, i got sent a 3ohm not a 5ohm.

[Bodi]

You have to file a bit off the stock coil supports to mount Dyna coils but stock ones will still fit afterward. Being able to replace the cables is nice.

[bjbuchanan]

Get used Andrew's coils off eBay. Work great and fit stock brackets. Reusable wires as well, 4.8 ohm with correct angles.

They wake the bike up at a nice price

[dave500]

kill/key switch getting too wet?