GS425 Replacement Coils

[yanagawt]

I recently picked up a decent looking non-runner for a real good price. To my dismay, during the tear down I noticed the PO had rigged in a coil that doesn't appear to be quite right.

He combined the hot wires for both coils and had it connected directly to the battery. Either way... I'm looking for possible replacements or options to buying the factory coils for >$200! Would coils from a larger bike work? If so, how would I go about verifying?

Haven't tested anything, but I deffinately need to replace the 'other coil' wrapped in about 3 ft of electrical tape... Any suggestions?

Looking forward to this build-up, its my first, and my first suzuki.

Thanks!

[salty_monk]

Yes is the obvious answer but I'm not 100% sure how your bike works.... I suspect it's wasted spark with the one coil firing both cylinders.

If that's the case any 3ohm coil would prob work if it will fit physically. Dyna, Accel or one from a bandit or something.

Nessism had one of those 425's I think & might even still have some parts from his wreck....

Dan

[yanagawt]

I apologize if my post was unclear, its a 425L (not sure if that makes a difference), it appears that in the stock configuration it utilizes 2: two-wire coils, 1 per cylinder.

I haven't received the manual I ordered so I am unsure of how the stock wiring was configured, however, I am pretty sure it shouldn't be attempted to fire in this config. Instead of using the wiring harness power connections (orange/white leads) both power leads from the coils are spliced together and connected directly to the battery power.

I have seen the accel kit, but am wondering if the coils are a direct swap or if modification is necessary for use. I don't mind spending a little $$ to get it running good, but for $100/stock coil its a bit out of the price range considering the bike was less than that...

Anyone with a 400 or 425 that can chime in regarding the ignition? I understand they have a slightly different design from the larger bikes and 79 was not a good year for ignition.

[tkent02]

Look here:

http://www.babbittsonline.com/pages/parts/viewbybrand/1/default.aspx

Looks like two coils with a single spark plug wire on each.

[yanagawt]

tkent02, you are correct, but I am not sure what you're suggesting. Here is an attempt to describe what I'm looking at.

The 'other' coil appears is a 2-wire model w/condenser, but it is not setup like the OEM. one wire is grounded and then hooked back into the black harness wire. Both power wires are tied together and hooked directly to battery.

[tkent02]

tkent02, you are correct, but I am not sure what you're suggesting. Here is an attempt to describe what I'm looking at.

The 'other' coil appears is a 2-wire model w/condenser, but it is not setup like the OEM. one wire is grounded and then hooked back into the black harness wire. Both power wires are tied together and hooked directly to battery.

Why not get a used coil of the correct type?

[yanagawt]

I've been looking but haven't located a source. Thats also why I'm wondering if coils from a 450 would work since theres a few in the salvage yard in town.

[tkent02]

I've been looking but haven't located a source. Thats also why I'm wondering if coils from a 450 would work since theres a few in the salvage yard in town.

Bring your good coil to compare. It would work electrically, might not mount the same but it probably does.

[yanagawt]

Whats the purpose of the condenser? Is it necessary?

[tkent02]

Yes, it reduces the size of the sparks across the points as they open, it prevents the contacts from burning up very quickly. Usually the condenser is near the points, if it is near the coil that's OK too but it needs to be somewhere.

[yanagawt]

Well the 450 in the yard has electronic ignition. Thus, I suspect it would have 3 ohm coils (didn't bring the multi along). My understanding is that the 3ohms are not compatible with the points systems.

Heres my idea: Use the 450 coil with inline 2 ohm ballast resistor and the condenser. 3 ohm + 2 ohm = 5 ohm (points compatible).

Would there be any adverse effect of using just one 450 coil in this manner? I'd use the one good stock coil and one 'modified' 450 coil.

Basically, I want to verify that the bike runs before I start putting money into it. Goal would be to eventually do away with the points and run the dyna setup for this bike.

[Nessism]

It's no big deal using a dual plug wire coil, just use one of the wires and seal off the other. Hook up everything per the factory manual and get the bike firing. You can check the resistance and add ballast resistors are needed - you want about 4 ohm or so.

[yanagawt]

I've been confused about the replies all day and finally realized why... The coils I have (and the 450's I am looking at) have 1 spark plug wire each. By 2 wires I mean, + & -. The OEM coil has 2 wires, but the 'other' only has one. The PO grounded the black wire running to the points and hooked the + in parallel with the OEM coil directly to the battery.

Either way, I haven't verified if this setup was working besides the PO saying it did.

Sorry for the confusion, I am obviously not so good at explaining what I'm thinking.

Thanks for the replies and assistance!