Cheap source for new coils?

[Buffalo Bill]

Bikes lag behind car engineering.

Ive only seen ignitors be bad and NOT WORK. ive never heard of one that partly works. I know that some of the later bikes with electronic advance can have ADVANCE problems crop up, but I was always under the understanding that the ignitor either works or it doesnt work...you can also talk to Griffin. He had a coil or set of coils that acted fine untill they got HOT, and then started crapping out. Took him a while to track it down, but finally he took the bike out, got it nice and hot then quickly shut it off, pulled the tank and tested them before they cooled off and sure enough they were crapped out when hot.

All that you've written I've read before in other posts. I did a search on the issue earlier this summer and read up on it all. Also cars have coils too, so in that regard I have plenty of same experience.
The bummer for me is: How come very good car coils sell for lot$ cheaper? I remember some cars having a mini coil on and for each plug since the '90s. That would be cool mod!
Bill

[Buffalo Bill]

Suzuki coils.

Bill, all of the late 80s/early 90s Katana & GSX-R coils are good replacements & they are CHEAP used on ebay. Ray.

thanks a bunch! In the schematic for the GSXF600 Katana I saw on bikebandit, they look like GS coils.
Bill

[chef1366]

Ive only seen ignitors be bad and NOT WORK. ive never heard of one that partly works. I know that some of the later bikes with electronic advance can have ADVANCE problems crop up, but I was always under the understanding that the ignitor either works or it doesnt work...you can also talk to Griffin. He had a coil or set of coils that acted fine untill they got HOT, and then started crapping out. Took him a while to track it down, but finally he took the bike out, got it nice and hot then quickly shut it off, pulled the tank and tested them before they cooled off and sure enough they were crapped out when hot.

I've seen them work but not well.
Hit a brick wall at 5k.

[mike_of_bbg]

I've seen several reports on this board of ignitors overheating, and thus stop sparking causing the engine to die, on long rides. That was my own personal experience as well.

[Roger P.]

Pins and sockets in the connectors start to get loose, work sometimes, don't work other times. PITA to diagnose. Pull the plug apart, clean both pins and sockets, crimp the sockets a bit tighter to provide a good grip on the pins, apply a bit of never seize to both and away you go.

[Buffalo Bill]

Make Opie cry?

Wait a minute, isn't the warranty up at the end of your driveway?

Andy Taylor would give 'em back their money, because the coils were going bad before they came over.
If deputy Fife hadn't pulled them over, the boys would've had a fast ride home.
The buddy was actually riding the bike for the buyer, and he was the sour puss that spoiled the deal. His regular ride is a CBR1100, so a GS550 on it's best day would seem lame to him.
Too many negative actors spoiled the transaction.
Bill

[Texas Don]

Bill,
Did you read the resistance on both the primary and secondary windings of the coils? If they read the same, the coils are good and replacing them is just throwing good money after bad. It's just as likely, electronically speaking, that the relay you just added to the circuit is bad and only working intermittently. If you can't condemn a part by a repeatable, verifiable test, then you shouldn't replace it. Even out of a sense of frustration. I've been there. My Voyager's alternator died the morning that I had a buyer coming to look at it. I took it out for a short test drive to warm it up and it threw diode particles through the air vents. That was easy to diagnose but still required that I check the output before spending over $300.00 for a new one.
Coils are truly simple devices. They have no moving parts and consist of coils of wire wrapped around a steel or copper core. The proper way to check a coil is to read the primary resistance with an ohm meter. Then the secondary resistance. Then read primary and secondary to ground and to each other to insure that you don't have a short or partial short. If those readings are good, so are the coils.
I would be looking at the igniter as well. It is far more likely to develop an intermittent type of operation. Since transistors are semiconductors, when they begin to fail, they can reverse operation under load and depending on temperature conditions, they can do it indiscriminately enough to cause even a good technician to pull his hair out. The only way to check one, unless you have access to some pretty sophisticated test equipment, is to sub a known good one.
PM me if I can be of further help. I spent 8 years in Uncle Sam's Nuclear Navy chasing electronics issues. I'm no wizard, but I do have some taxpayer funded education that I would be glad to offer in assistance.
Don