I know I'm asking about an old 450, but it is a gstwin. I'm really just curious to know if anyone has fitted a modern 500 ignition system to an older 450. My ignitor died and its wicked expensive to replace. Being as newer bikes have cheaper parts I was hoping to fit a newer system from signal generator to coils to my bike.

Has anyone seen, heard, or actually done this? Is it possible or are the model years too different?

Please don't tell me an answer like anything is possible with enough custom parts, money, and time. I'm trying to find a cheap solution to my problem.

There are a few members here who may be familiar with some 450 parts swaps, including a couple build threads over in the 'projects/builds' subforum. 
A quick look pulled up this one below, but there are more.  Maybe one of those members knows more?

http://gstwins.com/gsboard/index.php?topic=62057.0

Otherwise, I suggest you also try asking over at www.thegsresources.com
Some of those members are incredibly knowledgable about the old twins and may have other suggestions or ideas. 

- Bboy

Based on a parts list for 85-88 GS450 it has 2 signal pickups like the 89-2002 GS500.

The ignitor unit on 89-02 GS500's is really simple: 2 signal pickups going in and 4 wires out: 2 to each spark plug.

The timing pickup is the same part number
GENERATOR ASSY  33110-44420    1    $205.04

Ergo - the ignitor should work the same. You may have to splice wires if the connectors are different. But with the same part number, the connector on the end of the pickups should be the same connector.

Compare the wiring diagrams for your bike and the 89-2000 GS500E. See if the ignitor has the same number of wires: 3 in from the pickup, 4 out to the coils.

Wow, thanks for the quick responses. I was over at gsresources and they are the ones that suggested the ignition from a newer bike.

after looking at the wiring diagrams, yeah you can make it work. You'll need to wire it correctly and carefully.  they are functionally the same. Will the ignition curve be the same? haha, who knows.

The GS500E ignition is stupid: it only triggers a  spark based on the timing pickup.

The 2004+ ignition has some smarts with the TPS, 1st and 2nd gear sensor and other stuff. Also only a single timing pickup.

Timing rotors even for 89-00 and the 450 are not the same part. The pickups are the same, though. Given that, I do not think you could fit the 2004+ rotor on and use the 2004+ ignition.

Use 1989-2002 ignition unit and you should be OK.

I know the crank is the same, at least up to '00, as I have a 450 crank on my bike. So can't go wrong as far as what Adidasguy said.

Had a 450 once. Ignition box went dead. They tend to do that after old age.

Stay away from eBay and junk yards. Its potpourri there. Find someone on the gsresources that has one in known working condition and strike a deal. That's how I fixed mine. Some saint in NH had 3 and said "make one work from the 3 and ship the rest back". A godsend.

Or...fabricate one from an older gs500.


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I know you can do it the other way round, my 500 has a 450 pick-up and CDI unit on it. Get wiring diagrams from both bikes and take your time.

What's the issue with different ignition curves and would that cause major problems? I think I found what I need locally, but if it doesn't work I'm going to try to swap with a newer 89-02 gs500. I think it would be the easiest/cheapest way to go. Thanks again for all of your help.

I don't think there are any ignition curves on 89-02 GS500's.
The ignition is a stupid box. All it does is take the pulse from the pickup and fire the plug. Nothing more. No smarts or timing adjustments at all.

The 2004+ has smarts and does do timing adjustments based on throttle position and what gear you're in (bike gear, not what you are wearing). Well, maybe? If your helmet color doesn't match your jacket and doesn't match the bike color is the timing retarded?

Phillip - if km not mistaken, the GS450 does have ignition curves built in. I think I read about it in the Clymer's manual?

If it does, Pete would know on the GSResources.