Rebuilding my 1978 GS550C here...

[isu2014]

Hello all,

Here is my 2nd GS project. It's a beauty.

What I know:
Points are good, carbs are clean, brand new battery, tank is clean, everything is here.

The issues:
It won't start. No spark on 2 cylinders. Needs a seat cover, mirror, headlight bulb, cleaned and polished.

 

[Nessism]

Wow, bike looks to be in nice shape.

Unless you did the work on it, I wouldn't believe it.

Good luck

 

[isu2014]

It's all original so it has a few flaws but it's even better than I originally thought. It will polish up really nice I'm sure.

 

[isu2014]

I washed the bike today before I unloaded it. Easier to get to the car wash... Not much rust to polish off but the engine case has some corrosion but not too bad.

 

[musicman]

Wow, looks to be in great shape!

 

[isu2014]

I was just looking through the box of miscellaneous parts the dude handed me when I bought the bike. I didn't know what was there besides the headlight trim rings. Turns out he ordered over $200 worth of NOS Suzuki parts. Headlight rings, chrome turn signals, a bunch of fasteners and some other stuff. Not bad.

 

[isu2014]

Found something shocking when I was going to check the points that the guy said he checked and verified. Dyna S. This is a game changer. I don't know squat about this system. I do know the bike still has original coils, which I don't think are good for this system.

 

[hakim5857]

What a great bike you have there with part included. Happy rebuild...

 

[Nessism]

Found something shocking when I was going to check the points that the guy said he checked and verified. Dyna S. This is a game changer. I don't know squat about this system. I do know the bike still has original coils, which I don't think are good for this system.

The Dyna S is designed to work with stock coils.

 

[isu2014]

The Dyna S is designed to work with stock coils.

Yeah I guess I was reading that after I did some research. Of course Dyna wants you to buy their coils but probably not necessary.

The bike is buried in a snow bank now after a few days of crappy weather, covered of course. Won't get to work on it until this weekend. The previous owner claims he checked spark on all cylinders and only 1 and 3 have spark. One coil powers 1 and 4 and one coil powers 2 and 3, so what would cause only half of the coil to fire? A bad Dyna S? Incorrect timing? Bad coils? Like I said, I don't know squat about this setup.

 

[hakim5857]

Yeah I guess I was reading that after I did some research. Of course Dyna wants you to buy their coils but probably not necessary.

The bike is buried in a snow bank now after a few days of crappy weather, covered of course. Won't get to work on it until this weekend. The previous owner claims he checked spark on all cylinders and only 1 and 3 have spark. One coil powers 1 and 4 and one coil powers 2 and 3, so what would cause only half of the coil to fire? A bad Dyna S? Incorrect timing? Bad coils? Like I said, I don't know squat about this setup.

Check the wiring to make sure all in good order. Wire from Dyna S to coil, coil ~ plug wire to cylinder. Go to BikeCliff's Website and you'll find all the info to troubleshoot the problem.

 

[isu2014]

Finally got to work on the bike. Replaced all the plug caps with new NGK ones. Then I tested spark and have it on all 4 cylinders. So that's good. Not sure why the previous owner lied about not having spark. I'm checking for fuel next.

 

[hakim5857]

Finally got to work on the bike. Replaced all the plug caps with new NGK ones. Then I tested spark and have it on all 4 cylinders. So that's good. Not sure why the previous owner lied about not having spark. I'm checking for fuel next.

That's great , get new petcok, clean up the fuel tank & carb. Change all rubber O ring in the carb. Here some tip and info;

Carb rebuild tutoria from Nessim >>>
http://www.mtsac.edu/~cliff/storage/...d_Tutorial.pdf

Buy new rubber O ring for your carb ;
O-rings for Suzuki GS850 Mikuni Carbs

Petcok or other part you can find at
>> http://www.z1enterprises.com/
>> Partzilla.com - OEM Powersports Parts from Honda, Kawasaki Polaris, Suzuki and Yamaha at discounts up to 80% off MSRP
>> www.ebay.com or you can ask GS member here whether they have extra part

Last but not least >>> have fun rebuilding it...

 

[isu2014]

Thank you for the links Hakim. Carb rebuild is next.

I got the bike running but only on full choke. Definitely needs more gas. It pops when I give it gas and won't rev very much. The timing is probably off too but it's hard to tell when it doesn't run well to begin with. I took a video of it. Sounds like it might be missing but I'm guessing one cylinder isn't getting much gas at all.
http://www.youtube.com/watch?v=l6UoUZ2D9ow

 

[isu2014]

I brought it back inside and took the carbs off. I found some oil in carb 2. Probably needs a valve job.

 

[wedoo2]

Nice. Wish my bike had pipes that good.

 

[isu2014]

Started rebuilding my carbs and I found a little issue.

What is the significance of this piece and is it repairable without buying a carb body? These are the VM carbs.

 

[isu2014]

Here she is, singing the best music a man can hear! I haven'y even tuned it yet, and it runs fantastic. All carbs are clean and I made sure the boots sealed up well around them. I also bled the front brake today.
http://www.youtube.com/watch?v=nNPIeIroqgQ

 

[isu2014]

Had the bike out for a good ride today. It runs pretty good. I did some tuning in a last few days and got it pretty good, but it's not perfect. The idle creeps up a little after a hard ride. I'll be working on it some more. I also noticed the rocker cover gasket seeps a little oil. I half expected it to since it's 35 years old. And the speedo seems slow to respond. I'm going to lube it.

 

[GS Jim]

Have fun with it Isu, sure brings back memories. My first GS was a 1978 550 like yours. Had it all thru college and toured all over the South West on it.