1981 Suzuki GS450S- Recent Electrical Upgrades w/ photos

[Guest]

First off -GSR is awesome. Thanks to all who post their in depth modifications/upgrades and the photos to go along with it.

Long story short I was invited to go on a rad S.Eastern Ohio ride with my friends Chuck (Chuck78) and Grant last fall. My 550 was not road worthy so I asked my girlfriend if I could ride her 1981 GS450S that I just purchased for her about a month before….Thankfully she allowed it. During the ride I began having issues around the 2-3 hour mark after we hit the freeway out of another twisty section. Lights blowing out, inconsistency in RPMS etc. The regulator failed. We bump started it a couple times (we had to have pushed the bike up and down this hill 12 times, belated apology now to my riding buddies for that...) and even tried to jump it from a nice bystanders car with no avail. It was determined there via multimeter that the charging system had failed. More specifically the regulator, this likely led to the stator, ignitor(got so hot it cracked the back housing), signal generator and coils also failing . So here we are in the spring, after it sat all winter in the garage, and I've finally got it back on the road. With my first GSR post I feel like I owe it to all of you to share my work since I have had SO much information help me along the way on this bike and my unfinished 550! I did my best to provide part numbers, price, details and a photos for each part swap.

SH775 Regulator (USED from 2015 Polaris Ranger 570)
# 4012941
Ebay $44.99

Aftermarket Racetechelectric/ RMstator Plug Kit
Amazon $15
(also on eBay)

Many write ups on GSR regarding this upgrade, not going into much detail on this. Comment/PM me if you begin to get too far off the path.

Quick rundown:
3 stator legs, in no particular order at all(does not affect adaptation) run directly to gray/bottom connection. On top of black connection run the ground(black wire) to SPG (single point ground). Ground-check-done.
Skip the middle and you now see the red wire exiting the black connector. This positive wire runs directly to battery positive with a 20A inline blade fuse between battery and SH775.

[drey6]

1989-2000 GS500 Ignitor unit.
# 33120-01D10
Purchased at Rice Paddy Motorcycles in Columbus
( ricepaddy.com )

Note: To keep it simple(cheap!) for me I cut the original wires w/connector off of the original 450 ignitor (#32900-47020), soldered connections, double shrink wrapped to create plug and play retrofitted unit. All wires align with original ignitor pigtail aside from one minor difference- the black/white wire. The GS500 ignitor ties its blue/black to stock 450 black/white ignitor pigtail/ @point of connection. The black/white out of GS500 ignitor goes to the SPG (see photo)

Also, I modified the side panel for mounting. The metal tab that originally protruded out in the center was trimmed. I hammered flat the left portion sticking out. Additionally I drilled to mount holes and welded two bolts through the backside acting as studs for easy ignitor mounting with nuts. Also hammered down the bottom plate mount, sanded off paint and greased to use as my SPG location. Used old engine ground cap+tape to keep it protected from debris.

[drey6]

1989-2002 GS500 Signal Generator
# 33110-44420 (signal generator)
# 33120-01D10 (rotor)
Stock rotor mounting bolt is identical to GS450
Purchased at Rice Paddy Motorcycles in Columbus

www.ricepaddy.com

Easiest part of all swaps! Remove all original ignition components (mechanical advance, rotor, signal generator [NO need to remove oil pressure switch that green/yellow connects to, just turn screw a few turns to release wire] ).
GS500 signal generator has a different kind of heat protection covering wire but I chose to remove original cloth heat sleeve from 450 signal generator for peace of mind and it fit snug over GS500 harness.

[drey6]

1989-2009 GS500 ignition coils
# 33410-01D00

My coils are from a 2006 GS500F on eBay
$ 27.44 shipped

These are awesome for 3 reasons.
Reason 1- They are much smaller than original.
Reason 2- The input wires are not directly soldered to connectors that then go to the harness. Just spades is all you need for the gs500 units.
Reason 3- Wires are replaceable unlike old coils that once trimmed back over the years become too short and need replaced altogether.

I tossed the original wires and caps from GS500F coils when they arrived and twisted on some fresh wire, OEM NGK VB05F Caps and OEM NGK B8ES plugs from Rice Paddy.

Notes: These were not simply “bolt-on” for me. The 2 stock mounts over the frame had mount holes that were spaced correctly for coils, which definitely helped. However when I attempted install after new spark wires were on coils it was too tight to each respective frame rail on right and left. So I bent the mount tabs a bit to get them in. It's tight but works fine. To help some out with wiring I'll mention that the coil power wire(spliced off of orange/white) that goes to each coil- (red wire was used in my case) goes on the terminal opposite of the spark plug wire on each coil. Then white to left coil nearest the spark wire and black/yellow to right coil nearest spark plug wire.

I recently added extra heat shrink sleeve over the spade connectors so that when fully connected it covers the exposed coil input terminal. I'll snap a better photo when i pull the tank to rebuild the carbs with my www.cycleorings.com kit.

[drey6]

During all of this I also completed the coil relay mod and additionally ran a new 20A inline blade fuse in place of the old glass type that we found last fall on that sad day to have frayed wires entering and exiting the fuse holder. Probably didn't help along with the other issues that day!
For those that find this helpful, please comment with questions on this thread under any of the swaps above or to other threads pertaining to the topic if they are not too old so that you can be sure of your connections before giving power to the system!

Shoutout to my buddy Chuck (Chuck78) for the guidance and tips during this process! So pleased to hand this bike (roll??) back over to my girlfriend knowing it’s in tip-top electrical shape for her to learn and explore on.

[drey6]

Figured I should leave a photo of the bike as well just for kicks.

[1948man]

Figured I should leave a photo of the bike as well just for kicks.

I was always partial to the "tires up" model. Seriously, kudos for some good work.

[drey6]

Lolol! I tried to flip it and repost and it did the same thing. I'll try on my computer in a bit.
Thanks for the kudos, but seriously- GSR is king. So much helpful information.

[Circa87]

THANKYOU very much for this thread mate. About to do my electrical. Your thread is very much appreciated!

[pete]

Ah someone at last has put a GS500 ignition onto a 450, great stuff! Keep us up to date on how it performs, this is my backup plan should my stock ignitor ever die. While I knew everything *should* bolt on, I've never seen it done yet.

Thanks for the write up and details, it's good to know!

Any issues lining timing marks up or anything like that?

[John Park]

Is there something electrically different about the GS500 coils? It seems like almost a plug and play if you use the 450 ones. That said, I guess the object is to make an electrical breakdown something that a Suzuki dealer can deal with out of readily available parts. With a little help from Polaris…..

[pete]

When I looked into this, I'm pretty sure the 500 coils were identical specification wise. Being smaller would be good though as it can get a bit tight in there once you route the harness and clutch and throttle cables. In my case I have the choke cable going through there as well due to having the 500 carbs on.

[drey6]

Haven't set up email notifications to this site so I have failed in responding. My apologies!
Since completion of this work I recently moved and bike was starting/running well enough to ride to new home. However I knew a carb rebuild was in order after settling in. Rebuilt carbs over the last month along with toying with my newly acquired 1984 PE175 and today have finally reinstalled carbs/airbox/etc. She fired up with ease but unfortunately I had to kill it due to a simple mistake on my part, I purchased incorrect fuel hose size. Just slightly too large so it was leaking at the fuel "t" connection point. I will replace that by the end of this week and begin dialing in the carbs so that they are spot on. Hopefully can catch a warm day to go to Chucks house if he is available for help on confirming it's timing since I've yet to learn this process yet. I will let you know what I discover on those grounds as time allows. Glad to read some feedback that this has been helpful and also to see some others able to confirm operation at the least on some of these swaps that have mostly been mulled over without any direct application to judge upon. Next up after all this I hope to finish my '80 550E before spring and potentially get something going on my titled GS1100 frame and engine/spare parts that I have picked up on the cheap!

[drey6]

Is there something electrically different about the GS500 coils? It seems like almost a plug and play if you use the 450 ones. That said, I guess the object is to make an electrical breakdown something that a Suzuki dealer can deal with out of readily available parts. With a little help from Polaris…..

No major difference aside from being only a decade old from a low mileage bike as opposed to a 36 year old oversized set. Also having the option to install fresh spark plug leads is a big bonus along with no hardwired connections but instead spade connection points. Technically there are a variety of coils available to use at the correct ohm range.

[posplayr]

1989-2000 GS500 Ignitor unit.
# 33120-01D10
Purchased at Rice Paddy Motorcycles in Columbus
( ricepaddy.com )

Note: To keep it simple(cheap!) for me I cut the original wires w/connector off of the original 450 ignitor (#32900-47020), soldered connections, double shrink wrapped to create plug and play retrofitted unit. All wires align with original ignitor pigtail aside from one minor difference- the black/white wire. The GS500 ignitor ties its blue/black to stock 450 black/white ignitor pigtail/ @point of connection. The black/white out of GS500 ignitor goes to the SPG (see photo)

Also, I modified the side panel for mounting. The metal tab that originally protruded out in the center was trimmed. I hammered flat the left portion sticking out. Additionally I drilled to mount holes and welded two bolts through the backside acting as studs for easy ignitor mounting with nuts. Also hammered down the bottom plate mount, sanded off paint and greased to use as my SPG location. Used old engine ground cap+tape to keep it protected from debris.

I hope you still have the heavy engine groudn strap going to the negative side of the battery?