1980 GS 550L Project/Rebuild

[Guest]

Hey everyone,

I am posting this thread for my 1980 GS 550 L Project/Rebuild that I started about a year ago. I have been on the forums for the past year while working on my GS, but have not made a post. While rebuilding my GS this forum was extremely helpful, so I want to throw out a big thank you to everyone on here... Without you all I would have had a lot more trouble rebuilding my bike. I am going to take you all through my rebuild from the time I bought the bike to now.

In the summer of 2015 my boyfriend taught me how to ride on his Sportster... I grew up on dirt bikes and quads, so I learned pretty quickly. I started thinking I would want my own bike, and so we both started looking for a good, reliable bike for a beginner. We ended up finding a 1980 GS550 listed on Craigslist in New Hampshire. We called, and the guy said he would deliver it for an additional fee; so there I was into a project bike for low money, and I was more excited than ever!

1 - 1.jpg Here is the bike on the truck the day it was dropped off!

The bike came pretty much all original with 8000 miles on it... The things that were missing: air filter component, air box cap, battery side cover (of course ), and the pipe was changed to a Kerker 4-into-1. The previous owner bought stock size jets and was going to rebuild the carbs, but said he didn't have time. The bike also came with K&N oval pod filters, but thankfully the stock air box was there (mostly).

So, right off the bat I knew I would be getting into the carbs (something I had little experience with before), I would need to rejet, and I needed to find some missing parts.

[dazzelindevils]

First step: Getting into the carbs and assessing the damage

First off, I want to throw out a thank you to Cliff and all of his tutorials. He had an awesome tutorial on rebuilding Mikuni BS32's that was extremely useful as I learned how to clean and rebuild carbs.

1 - 15.jpg This is me working on my carbs while eating a cookie apparently haha

It was nice that the PO bought all new rebuild kits, although I knew I would have to rejet eventually, but to get a baseline the stock jets worked well. I unscrewed the caps, checked the diaphragms, and eventually worked my way down to the float bowls. As I am working through each float bowl, taking out all of the jets, and carefully inspecting the carb body I get into Carb #2 and notice something... A broken float post. Immediately deflated, I thought this was the end... I would be buying a new carb, if I could even find one.

Well, I ordered a used carb body off of eBay, but it turned out the be for the wrong side. So being the stubborn girl I am, I thought what the heck... I am going to try and reverse/drill out the carb body and make it work.

[dazzelindevils]

Here is a photo of my attempt at a reverse operation...

1 - 8.jpg

I thought drilling out the opposite side for the fuel connector, and plugging the other side would work just fine... I reassembled the rack of carbs and put em on the bike thinking everything would be fine... Needless to say, it didn't work, and turned out the we drilled into the air passageway by accident... Oh well, it was wishful thinking.

[dazzelindevils]

Back to square one...

I've got a rack of carbs, one with a broken float post, which most people were saying is the death of the carb body, but I rejected that idea... and even more I rejected the idea of paying a crazy amount of money for a replacement carb body.

It was time to get creative... I started getting busy with school, and so I put my GS on the back burner. Not too long after, my boyfriend found an interesting story of an Australian dentist who was riding through the Outback, and one of his float posts ended up snapping somehow. He was stranded with no way of contacting anyone for help, and so he conjured up a way to fix his float post. He thought of the post as a tooth, and drilled out a little slit in the post and connected the two pieces with a wire. Not a permanent solution, but it got him home safely!

Now we took this to the next level...

We carefully dremelled out a little hole to fit a steel post into. We filled the hole with gas resistant devcon and clamped it together for 24 hours. The next day we checked it, and it was solid! In fact, more solid than any of the other float posts in there... We considered our venture a win, and reassembled the rack of carbs.

Step Two: Putting the carbs back on the bike... your worst nightmare

First off, getting these friggin carbs on is the absolute worst thing ever! So if anyone else has experienced this... you're not alone. We tried the normal careful and gentle way. We tried wiggling, and pushing with anger, but those friggin things would not go in. Finally, we decided on this method, which we now swear by...
1 - 34.jpg This is my boyfriend holding a strap around the base of the carb bodies and bracing against the frame...

Seriously, this method has got to be the safest and most effective way of getting the carbs into the intake boots. With a little pull and some guidance from the air box side of the carbs, they popped right in!

[dazzelindevils]

Our dental operation on the float post worked! To this day that float post is solid, and works perfect!

Here I am riding my bike the next day!

1 - 2.jpg

Now, there were some problems. The bike was running, that was awesome, but it wasn't running great. It had a racing idle, and was running pretty hot.

We did an oil change, actually several oil changes, because the oil was so gunked up. We tightened up the air box as well, but I still needed some parts. The oil change and tightening up the air box helped with the racing idle a bit, but I needed to order the air box cap and filter component.

I found a filter on eBay that was in great shape, but the filter cap was harder to find. Eventually we found one on craigslist in California that the guy shipped out for us. It finally arrived last week!

Now that the air box was all tightened up, had the proper cap and filter component, I was more confident that the bike would run better. It definitely ran better, but still hot and lean... I knew the issue would be the jets.

[dazzelindevils]

Step Three: Rejetting for a 4-into-1

I did my research, and on a jetting thread and found some helpful information useful to apply to my bike.

Stock jets in a 1980 GS550 are 92.5 mains and 40 pilots... Considering I had a 4-into-1 Kerker pipe and stock air box, bumping up the mains to 100 and the pilots up to 42.5 should do the trick.


After this we put the carbs back in, and tightened up all of the boots with new clamps.

I rolled the bike outside, and it started right up, and idled right where its supposed to! It wasn't running hot anymore, and it had much more low power. Also, it had more range and power through the rpms.

We were both so excited to have brought this bike back to life!

1 - 43.jpg

[dazzelindevils]

Step Four: Brakes

We know a young motorcycle mechanic, who just graduated from motorcycle mechanic school, so we asked him to do the brakes since that is considered a little more advanced.

I ordered new brake pads, and the rotors were fine. We went through the operation of flushing the brake lines and replacing the pads. The front brakes were no problem.

The back brakes on the other hand, had frozen pistons. So our friend popped the pistons out, cleaned them, and put them back in their home. All set, we thought, Yay!... but nay... The next day there was no rear brake power at all, and the fluid level had dropped significantly. We noticed some leakage, and I thought "I am getting into those brakes myself."

1 - 3.jpg The problem: A missing o-ring

We replaced the o-ring and bled the lines again to get any gunk or air bubbles out that may be in there. Buttoned up the brakes, and voila! They are working! Crazy how a little o-ring can mean life or death (with braking power at least).

[cowboyup3371]

Great story and can't wait to see more

[dazzelindevils]

Did you catch a glimpse of those nice new tires in the last post? Yeah that's the next step...

Step Five: Tires

Well, the tires for a 1980 GS550 are an oddball size, and there aren't many manufacturers that make both sizes, but I found these Kenda Dual Sport tubeless tires online.

100/90 19 for the front
120/90 17 for the back

As many of you probably know, getting tires changed and mounted is pretty pricey. We were trying to look for an alternative to getting them mounted at a dealer in town, and on craigslist we found a listing for tire mounting $20 bucks per tire. Deal! Except they were up in New Hampshire... This worked out great though because my boyfriend and his friend, Tom, were going up to New Hampshire to pick up a GS Parts bike. Tom needed a frame and some other parts, and having parts on hand is always a good thing.

1 - 26.jpg Here's Tom on his GS!

[dazzelindevils]

My boyfriend, Rus, and Tom headed up to New Hampshire early in the morning and met up with this awesome couple who mounts tires on the cheap!

Jim and Keely were angry at how much shops charge to get tires mounted, and thought they could get people on the road without making them go broke. They decided to get a tire mounting machine, and started working out of their garage at their home.

For anyone in the New England area, these two are truly awesome people! It is totally worth it to go to them for your tire mounting!

Here is a link to their craigslist post: https://nh.craigslist.org/mpo/5598599990.html

1 - 1 (2).jpg This is their card...

[dazzelindevils]

Tires continued...

Jim was removing the old tires and discovered that they were actually tube tires... This was a surprise to all of us, but Keely found a place nearby that sold tubes for my bike for half the price that other places sell them for, and off Rus and Tom went to pick up the tubes.

The tires I purchased online were tubeless tires though, so this presented a problem.... Jim said that mounting the tubeless tires with tubes can be done but it won't be easy, so he needed a second hand.

1 - 5.jpg Here is Rus and Jim pulling the tire over the tube

[dazzelindevils]

Keely even scrubbed down the rims, and they look truly awesome!
1 - 1 (3).jpg

With the tires mounted, and the parts bike in the truck... Rus and Tom thanked Jim and Keely and headed south towards home. When they arrived, I was more excited than ever to get my new tires on my poor little GS which was being supported by a bucket over night. But first, we had to get the parts bike out of Tom's truck...

[dazzelindevils]

1 - 42.jpg Here is the poor, beat up GS550...

A little rusty, but I'm not complaining... I've already used two little rubber parts from it and it has only been here two days! Also, this thing still has the original Suzuki tool kit! So incredibly cool! Once I clean them up I'll post a picture for you all to see.

[dazzelindevils]

Now the tires are mounted on my GS and the brakes are working again! I registered the bike last week, and it is now on the road!



When this bike arrived, it had very little hope and was left to die. I wanted to be the owner that would bring it back to life, and we did just that! It feels so awesome to bring something that is 36 years old back to its former glory, and even better. Both Rus and I are so happy, and even took it for a ride the other day... we looked so dorky on it together, but the bike actually handles two people pretty well!

Next Step: Valves

Now that we have some mechanical experience with the rest of the bike, we feel confident going into the engine. At low speeds you can hear a little vibration from the engine... a loose shim. My next task is to go through the valves and replace any shims that are no good. My plan this winter is to give the bike a total run-through, paint the frame, pieces/parts, etc. But for right now, I just want to ride! I'll be sure to keep you all up date with what's going on!

[dazzelindevils]

Take a look at these Suzuki tools... Found an original tool kit in the parts bike. They were quite crusty of course, but I wire wheeled and clear coated to preserve them. 1 - 1.jpg Here is the before shot.