New Member Austin, TX GS750T

[Guest]

Hi all,

It's great to find this incredible forum with so many helpful people!!! I recently happened into the GS world when a friend gave me a 1982 GS750T in exchange for installing a starter in a 1973 Pinto. Only 16,941 miles. It had sat for about 15 years so I gave the crusty old girl a bath and her gleam showed a promising project ahead. While doing the carb rebuilds and other prestart essentials, I soaked some Marvel Mystery Oil in the cylinders to make sure the rings weren't sticky.

On the first start she only ran on one coil, so very rough. After cleaning as many electrical connections as I could find she started right up and ran smooth with great no-load acceleration. The spark from one coil is visually colder than the other and while riding under load, she stumbles and has no power. I've ordered a couple of new coils with wires and boots. The front brake also started to drag, so new caliper and master cylinder kits should arrive soon. Along with all the smaller parts, I've added a better seat, new tires and a nice big windshield.

Today, I'll look for ground connections and get them cleaned up.

In the mean time, I'm polishing and waxing to get a presentable look. I probably won't go further than knocking the crust and rust down, so she'll have some of that older bike patina.

I can't wait get this bike cleaned up and running - especially with all the comments I read about how much fun they are to ride.

This is my fourth Suzuki after an 800 Intruder, a 1400 intruder and a 2008 C109RT.

I've been wrenching all my life and have a small machine/fabrication shop and just love fixing and restoring anything that has a cool factor.

So happy to have found this forum and I hope I can be of help.

Dan

[Brendan W]

Hi Dan and Welcome
Known contributors to weak spark:
Coil supply plugs corroded inside.
HT lead cores corroded at caps. Snip off 1/4"
Dirty kill and ignition switch contacts. Open and clean.
Corroded fusebox connections and fuseholders.
These together could give back a full Volt or more at the coils.

[Rich82GS750TZ]

Welcome, from the proud owner of another 82 "T"

[GSXR7ED]

Welcome from another "T" owner. Lots of work in your future. Hopefully, funding shouldn't be much of an issue. Lots of elbow grease needed to make your "T" squeaky clean!

Ed

EDIT: Post a pic of your "T" here when you can:

https://www.thegsresources.com/_forum/showthread.php?228624-T-Nation-Thread-(My-2nd-Thread)-3rd-Overall-(I-think)&highlight=

[Redman]

Dan,
Thanks for introducing yourself.
You sound like an experienced knowledgeable person. Good.

Other typical ignition problem with these GSes is the sparkplug caps. They have a 5k ohm resistor in them that can go bad. Replacement caps (NKG) are available for about $5 each.

[danbob]

Brendan,

Thanks so much for your insights. Snipping the plug wires to get clean contact is a great idea. I had already cleaned the fuse holder, but not the fuse holder plug. Got that done yesterday - it wasn't too bad. Other connections on the bike were really ugly - especially the turn signal switch and the front brake switch. Tedious job with lots of tiny spring loaded surprises. Cleaned, greased and good now. I'm so glad you mention the ignition switch - I had completely overlooked that and I'll get it open today or tomorrow.

With the intermittent behavior of 1 and 4 exhaust running identically cold and warm, I'm guessing that the coil is probably bad. (Hopefully, not the igniter.) The Signal Generator ohmed out ok. After cleaning all of the primary connections, it still had intermittent power. So, I ordered a couple of coils with wires and boots. They should arrive tomorrow.

I found two ground connections on the plate that mounts the fuse box and rectifier. That plate is rubber isolated from the frame, so I have to find the other place(s) where it grounds to the frame???

The main ground on my bike is on the transmission case. Boy, was I kicking myself yesterday when I had to remove the carbs and airbox to remove that one screw. I had all of that apart when I did the carbs a couple weeks ago. It's done now and the ground connection should be strong for a couple of years at least.

There must be more ground connections? Toward the front? Any help on finding more grounds would be appreciated.

Thanks again,

Dan

[danbob]

Brendan,

Thanks so much for your insights. Snipping the plug wires to get clean contact is a great idea. I had already cleaned the fuse holder, but not the fuse holder plug. Got that done yesterday - it wasn't too bad. Other connections on the bike were really ugly - especially the turn signal switch and the front brake switch. Tedious job with lots of tiny spring loaded surprises. Cleaned, greased and good now. I'm so glad you mention the ignition switch - I had completely overlooked that and I'll get it open today or tomorrow.

With the intermittent behavior of 1 and 4 exhaust running identically cold and warm, I'm guessing that the coil is probably bad. (Hopefully, not the igniter.) The Signal Generator ohmed out ok. After cleaning all of the primary connections, it still had intermittent power. So, I ordered a couple of coils with wires and boots. They should arrive tomorrow.

I found two ground connections on the plate that mounts the fuse box and rectifier. That plate is rubber isolated from the frame, so I have to find the other place(s) where it grounds to the frame???

The main ground on my bike is on the transmission case. Boy, was I kicking myself yesterday when I had to remove the carbs and airbox to remove that one screw. I had all of that apart when I did the carbs a couple weeks ago. It's done now and the ground connection should be strong for a couple of years at least.

There must be more ground connections? Toward the front? Any help on finding more grounds would be appreciated.

Thanks again,

Dan

[danbob]

Thanks, Rich!!!

Ed, So far, I've made some fair progress with cleaning and shining. She's really looking like a different machine. I'll get pics posted as you suggest. Thanks!!!

Redman, Thanks for the info on the plug caps - good to know. I've got new coil kits arriving tomorrow. Hopefully, that does the trick.

[Brendan W]

There must be more ground connections? Toward the front? Any help on finding more grounds would be appreciated.

A lot of us have taken the frame ground wires from above the airbox and collected them to a single point ground ( see threads on SPG ). I use one of the mount posts of the starter solenoid. It has the two frame grounds, the R/R ground and a wire running to the battery negative terminal.
The idea is that the r/r runs the bike, not the battery, and it makes sense to let the r/r have a clear picture of the system. Returning through the frame can drop a few tenths and the r/r is unaware. It also helps charge the battery better.

[dorkburger]

Welcome. Not 100% sure, but I think 1 and 4 run from the same coil. If one works, so should the other. Definitely check the wires / caps. I had both corrosionnat the wire connections and a bad cap.

[Brendan W]

I'd double check the coil supply plug for #1 & #4.
See what voltage is there. Anything more than half a volt below battery is not good.
If a coil is poorly supplied, generally one plug suffers first.

[danbob]

Brendan,

Thanks for the guidance. I followed your suggestion and looked into the Single Point Ground discussions. I wasn't comfortable seeing that my bike only had a single ground from the battery to the engine case, so finding the recommendations to have a lead from the battery to the r/r ground made a lot of sense. I added one and also tied both the r/r ground and the harness ground to a single mount on the solenoid.

The SPG discussions also include some very in-depth info for testing and upgrading the charging circuit. Series vs shunt circuits. I'll have to learn and focus on that stuff a bit later. But, good to know it's there.

The coil kits arrived a day early, so I installed them last night. Along with that, I also took the right hand controls apart and cleaned the start and kill switches. I cleaned and regreased the throttle controls and oiled the throttle cable too, of course.

Hopefully, I can to start the engine today, but may not be able to ride as I have to rebuild the front brake hydraulics. The caliper kit should arrive today, but the master cylinder kit may not get here until tomorrow.

I see strong recommendations here to replace the brake lines, but my initial ebay search didn't get anything more than universal lines which didn't give me confidence in ordering. Any suggestions?

With fingers crossed that the coil and wire kits do the trick, I'm really itching to give her a ride.

Thanks so much for your help!!!

Dan

[Brendan W]

Suzuki called for a two year replacement schedule.
I imagine modern hoses are better.
A lot have moved over to braided s/s hoses.
They can be made up yourself.
There are surely some outfits in the US making them up.
Some of the other guys on here will be along soon enough.

[Rich82GS750TZ]

I see strong recommendations here to replace the brake lines, but my initial ebay search didn't get anything more than universal lines which didn't give me confidence in ordering. Any suggestions?

I got a braided stainless line, banjos, and copper rings from Venhill this past winter for somewhere in the $50-$60 range. If you like I can get you the invoice to show exactly what I bought after taking careful measurements of the original line I took off the bike.

[danbob]

Hi Rich, The length of the line would be very helpful. Thanks!!!