Need help identifying ignition parts on 1983 gs1100e

[adam83]

I'm going through my GS I bought a couple years ago and I'm trying to identify my ignition parts so I know what I'm running. This is my first GS, they are new to me and I don't have any reference.

It looks like this box is aftermarket. "3 Phase By Compu-Fire." Looks like its part of the charging system. Is this a decent piece? what does it do?

I suspect my coils have been replaced, as it looks like the wires have been spliced, and plug wires glued in. Am I right? If so, are these coils oem or did they come from something else?

Are my plug wires stock?

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[Rich82GS750TZ]

The Compufire is the Regulator/Rectifier, and is part of your charging system. If it wasn't doing it's job, you would know it, because your battery would run dead and not recharge while you ride.

The coils look stock to me.

 

[adam83]

Ok. Does it look like my coils have been replaced before? Why are the feed wires spliced with the red wires before they enter the coils?


Also, is this my cdi and is it stock?

 

[Rich82GS750TZ]

The red wires that feed your coils are not stock. You can check the original color wires on a wiring diagram for your bike. You can find service manuals with wiring diagrams and possibly high quality wiring diagrams on BikeCliff's Website. See link below.

What you call a CDI looks original. It's not actually a CDI, but is part of your ignition system. Search the forum for an explanation on what it is and why it isn't a CDI. That's above my pay grade.

 

[Grimly]

Those are stock coils, the epoxy oozing out is normal - it set decades ago. The wiring to the coils has been upgraded, likely because the original wiring got too shonky with the passage of time. The 3-phase Compufire regulator is a good bit of gear, keep it, it's most definitely an upgrade to the OEM piece of crap. The CDI isn't actually a CDI, but a Transistorised Ignitor.

 

[adam83]

Ok great, thanks for the info guys.

I was riding the bike through last fall with no issues. Then after sitting for about a week or 2, I went to start it and it cranked good as usual but wouldn't even try and fire. Cranked and cranked until battery died. I put it back in garage to deal with 'later,' and later turned into 6 months! I did put stabil marine into a full tank of gas before it sat, so the gas isn't gross.

Its almost certainly an issue of no spark or no gas, because like i said it doesnt even try and fire, just cranks.

So now I start the diagnosing, and i needed to know what ignition parts I had. Looks like I can perform the tests as described in factory service manual since everything is basically stock for ignition.

 

[Cipher]

Ok great, thanks for the info guys.

I was riding the bike through last fall with no issues. Then after sitting for about a week or 2, I went to start it and it cranked good as usual but wouldn't even try and fire. Cranked and cranked until battery died. I put it back in garage to deal with 'later,' and later turned into 6 months! I did put stabil marine into a full tank of gas before it sat, so the gas isn't gross.

Its almost certainly an issue of no spark or no gas, because like i said it doesnt even try and fire, just cranks.

So now I start the diagnosing, and i needed to know what ignition parts I had. Looks like I can perform the tests as described in factory service manual since everything is basically stock for ignition.

I have a compufire its robust though largish. Was over two hundred usd iirc.
they seem to be getting counterfeited or were bought out.
https://pertronixbrands.com/product...ltage-regulator-for-compu-fire-3phase-systems

 

[Nessism]

Maybe the petcock isn't letting fuel flow. Removing the carb drain screws below the float bowls will test that theory. For spark, remove one of the spark plugs, install it back into the plug cap, then ground the plug against the engine and hit the starter and watch for spark. All pretty easy stuff.

 

[adam83]

Yes you're right, and I did apply vaccum to the petcock diaphram on the 'on' setting and it did flow fuel today, so next I was going to put my inline spark plug test light between the plug and plug wire and see what happens.

But overall, Im using the opportunity to generally go through the bike. The tank is off and Im looking over the wiring, grounds, connections, parts, rubber, etc. its leaking oil at the valve cover gasket and breather gasket, so I will be replacing those and adjusting valves. My hanging aux fuel tank gets here tomorrow so Ill be able to do any troubleshooting beyond the basics if necessary. My petcock seems to be leaking too so Im ordering a K&L rebuild kit for it.

 

[Nessism]

My petcock seems to be leaking too so Im ordering a K&L rebuild kit for it.

Good LUCK with this. Rebuild success is less than 50%, especially if using K&L parts.

 

[Cipher]

Yeah buy a new one if available.

 

[adam83]

Interesting, thanks for the tip. Is there a better brand? The suzuki parts websites and motorcycle parts websites ive seen dont have any other option. Do they make the petcock assemblies new? Is there a diiferent petcock assembly from a another bike that works?

 

[Cipher]

Interesting, thanks for the tip. Is there a better brand? The suzuki parts websites and motorcycle parts websites ive seen dont have any other option. Do they make the petcock assemblies new? Is there a diiferent petcock assembly from a another bike that works?

It appears as NLA...
K&L whole units are reported to be similar to OEM down to the casting marks.
Try Yioutube for a tutorial on a refurb. If your current unit has no gouges in the tapered part that forms a seal then a polish with a conical felt dremel tube and metal polish may work fine.
Just slapping in new rubber and plastics bits into a old crusty unit is asking for trouble.

 

[first timer]

fyi the compufire stuff at least the one i had, doesn't like the high rpms and will burn out. Ran one on my KTM 990 that has about the same rev range as the GS and it didn't like the high rpm/voltage spikes. Ended up using a sh847 RR on it. The compufire stuff is engineered for lower reving harleys.

 

[Cipher]

fyi the compufire stuff at least the one i had, doesn't like the high rpms and will burn out. Ran one on my KTM 990 that has about the same rev range as the GS and it didn't like the high rpm/voltage spikes. Ended up using a sh847 RR on it. The compufire stuff is engineered for lower reving harleys.

Where did you buy it? Amazon lists a clumsily described knock off for 80 bucks vs 270 from the manu.
there are even fakes of the widely retrofitted sh775. You have to admire their market research.

 

[Nessism]

Here is a real deal SH775 for $35 shipped...https://www.ebay.com/itm/404242771507

These units are super robust, and almost never fail. The only issues I've found, is broken plastic connectors...and that's not even a dealbreaker.

 

[first timer]

Where did you buy it? Amazon lists a clumsily described knock off for 80 bucks vs 270 from the manu.
there are even fakes of the widely retrofitted sh775. You have to admire their market research.

I don't recall, it was several years ago. I am 99% sure it was a real one as the wires, connectors and general feel of the RR was high quality expected from a US made product vs cheap chinese knock off. I know what to look for and feel pretty confident it was the real deal. I have seen posts on the inter webs where others have also had issues with the compufire when fitting it to a high reving motor. You will see some ducati forums and GSXR forums people reporting similar.

 

[adam83]

Well, after cleaning my grounds really well, and every connection to the battery, and where the main ground attaches to the cases, and thoroughly recharging my battery off the bike with an optimate 4 charger, it fired right up.


I'm going to ride the bike for a couple weeks while I'm waiting for all my gaskets and then I'll be doing the valve adjustment, replacing some worn bushings and bolts, replacing a few wires, and some other maintenance