Coil Mod Gone Bad - 30 miles in at 70mph

[markdjr]

I just did the coil mod, everything was working great, but suddenly cruising down the freeway it went out on me. I'm looking for a higher quality relay right now, I used the only one my local had, but it's pretty cheap. Any other ideas?

I have a 78 GS550, I mounted it with a loose ziptie to the little tool box under the seat, tried to minimize vibration.

Thanks.

[p_s]

My first two lasted three blocks on zipties. The last one lasted 4k miles and then died getting onto an onramp. I bought a new ignition switch instead. The mounting seems to be pretty important. The first two I destroyed were Bosch, the one that lasted 4k miles was a no-name brand.

[Joe Nardy]

Try Parts Express. Excellent place for relays, wire, connectors, etc. Great prices and quick shipping.

Thanks,
Joe

[TheCafeKid]

Mine has lasted 2k ish miles with NO ties or what not. I just have it sitting, tucked under the coil. Its not long enough in wire to go anywhere, and the vibration there must be minimal. All Mr Steve's doing there...

[SqDancerLynn1]

My ign/coil relay has been on for 15K miles. If I had to replace it would probably cost $50 HD sealed weather pack relay (painless wiring), I'm guessing 30 amp Originally bought it to run a auto Holly elect fuel pump. Mounted near the start soloniod

[Macmatic]

I mounted mine to the main frame spar just forward of the coils. I zip tied it to the frame with a piece of soft foam rubber sandwiched between the frame and the relay. No problems yet but I've got two spares in the tail and I can always revert to stock in about a minute once I get the tank off.

/\/\ac

[chef1366]

Zip tied mine to where the airbox used to be bolted in

[hikermikem]

Just curious, what gage wire should i use to install one of these gizmos on the bike?? Use a 10A fuse I guess too?

Does this still apply to bike running aftermarket dyna coils??

[chef1366]

I used 14 gauge.
It can be used on any coils if you're losing voltage through your kill switch.

[rusty boltz]

Got mine from a junkyard for 3 bucks with wiring harness. Just chopped it off a mitsubishi suv. It was for the electric fan so I know it can handle amps well and is weather proof and vibration/heat resistant. I even grabbed another relay for back up for a dollar. I havnt found too many aftermarket relays that are reliable (especially from discount part stores) so I try to use factory grade ones if possible plus they,re under the hood of almost every car in the junkyard. Well, that and I'm a cheap bastidge but I've never had one that I used give me a problem.

[bwringer]

We'd probably see far better results if the relays weren't roasting on top of a hot engine.

Both my bikes have relays back under the side covers to power heated grips, and I haven't had any problems at all in two years of use. The relays are always on when the key is on (there's a switch on the handlebars to control the grips), so I guess I could also power the coils on the GS.

My relays are the cheapos from the auto parts store, intended to power driving lights. It's amazing how hard it is to find decent quality electrical stuff.

I do really like the idea of grabbing high-quality OEM relays from a junkyard. Can you give any tips on what/where to look for?

[rusty boltz]

Just about any car from the 90's up has a relay and fuse box under the hood (power distribution center). The relays used under the hood usually have seals around the plug and are more stout in construction due to the high heat and vibrations there. I usually grab ones for the electric fan or fuel pump but the horn relay is also made for high amps. These heavy duty relays will probably never see the load they were built to handle just as coil relays so I imagine they would last much longer. I use em in everything including the '04 chevy trailblazer horns (freakin loud!) I put on my 79 gs1000. I also prefer japanese or german cars to pull these off of because they are constructed well and use decent wiring in the harness (the newer the better) but most american cars probably use japanese or german relays anyway. Nothing that says made in mexico or china (sorry mexico and china).

[bwringer]

If you don't have a junkyard nearby or they have a really mean dog, this guy sells high quality relays for pretty reasonable prices:

http://easternbeaver.com/Main/Products/Relays/relays.html

Lots of other very nice motorcycle electrical stuff, too.

[82Shafty]

We'd probably see far better results if the relays weren't roasting on top of a hot engine.

Both my bikes have relays back under the side covers to power heated grips, and I haven't had any problems at all in two years of use. The relays are always on when the key is on (there's a switch on the handlebars to control the grips), so I guess I could also power the coils on the GS.

My relays are the cheapos from the auto parts store, intended to power driving lights. It's amazing how hard it is to find decent quality electrical stuff.

I do really like the idea of grabbing high-quality OEM relays from a junkyard. Can you give any tips on what/where to look for?

I used a 40 amp no name brand from Autozone which happened to be in the neon light section.

I've got 2K on it so far and it has done ok. Mine is also tucked behind the side cover.

[SPARKSS]

I just did the coil mod, everything was working great, but suddenly cruising down the freeway it went out on me. I'm looking for a higher quality relay right now, I used the only one my local had, but it's pretty cheap. Any other ideas?

I have a 78 GS550, I mounted it with a loose ziptie to the little tool box under the seat, tried to minimize vibration.

Thanks.

This is one of those ideas that seems good on paper. In practice, and with 38 years electronics (a lot of mobile and marine), 21 years as a mechanic, I can tell you that my first thought when I started seeing this idea on here, was that there was no way I'd add more connections AND an electro-mechanical switch (your relay) to a hostile - vibrating, wet and condensing, environment - and hope it was more reliable. Not on my bike.
I'd recommend that IF a problem appears with low voltage or other issues, understand, troubleshoot and repair the problem - the original design is really not that bad. My .02 worth.