Idles great, but won't rev...

[tom203]

Make sure you check jet sizes during cleaning process- in case parts bike carbs had been altered.

[oldbikefixer]

Figured out!

Good news... The problem was caused by the petcock not opening enough to allow the proper amount of gas into the carbs. I removed the tank and ran a fuel line from a gas can straight to the carbs, and plugged the vacuum for the petcock. The bike is now running much better!

All of this could have been avoided if the petcock had a "prime" position, which mine does not. I have a petcock from a Yamaha tank that looks like it will fit, and it does indeed have a "prime" setting. If it doesn't fit, then I'll try something else, like taking the spring out of the petcock and putting an in-line fuel shut-off valve between the tank & carbs.

I got a complete airbox from "Cowboyup", and I'm gonna install it this weekend. Since my present airbox is missing the element & lid, I'm hoping the new airbox makes everything right.

If everything goes as planned, there will be one more old GS back on the road this summer!

Now all I gotta worry about is cleaning a decade of crud off of the ol' girl...

[Nessism]

Um, your petcock does have a Prime unless it's an aftermarket petcock. Did you check the manual to see what they have to say?

[oldbikefixer]

Perhaps the petcock on my bike is an aftermarket unit. This is the first GS I've owned, and only the 2nd Suzuki - my first Suzuki was a '72 GT380 two-stroke, 3 cylinder, which I wish I still had.

The petcock on my bike is marked with "on" & "res" only, and the lever won't move past those positions to what might be the "prime" position. I've had it apart, and it's evident that it wasn't designed to function any other way.

Oh well, the petcock will be tossed into the scrap heap, along with all the other unusable bike parts that I've collected over the years.

"Check the manual"? I found this bike leaning against a shed, and the previous owner died back in '03. I consider myself lucky that his widow was able to find the title! Unless the manual is gonna be mailed to me from the "great beyond" sometime soon, I'm going to have to look for one on eBay.

[Nessism]

"Check the manual"? I found this bike leaning against a shed, and the previous owner died back in '03. I consider myself lucky that his widow was able to find the title! Unless the manual is gonna be mailed to me from the "great beyond" sometime soon, I'm going to have to look for one on eBay.

Basscliff has provided you a link to his website, inside you will be able to download the factory Suzuki service manual for you bike for free. You might want to go back and review the info that has been fed to your previously.

[BassCliff]

Hi,

(Where's my spoon?)

These are big files. Right-click and "Save as..." to save them to your 'My Documents' folder or similar.

GS550E/ES/L Servivce Manual '83 (149MB)

GS550 ('77-'82) Service Manual (72MB)

Depending on your internet connection speed, it may take up to a half hour to download these files, or days if you're on dial-up.

Click the link below that says "BikeCliff Website". Start with the 'READ ME' page.

Thank you for your indulgence,

BassCliff

[Seana23]

This happened to mine when i put a harris exhaust and pods onto my bike....
It seemed like too much air was bogging it down...
as i didnt want to downjet the air jets, i used sleeves over the pods made from inner tube and it seems to have cured it...
Alternatively you could upjet the main jets to equalise the fuel to air ratio...

Are you sure you cleaned out all the airways inside the carbs?

Could be punctured floats inside the carbs delivering more fuel than is needed...

Hope that helps some

[oldbikefixer]

Yeah, I'm a dummie...

So, I went to get that old Yamaha tank out of the shed to remove the petcock from it and see if it would fit my GS500E tank. To get to my shed, I have to walk right past the GS550L parts bike that I got for the sole reason of using as a parts supply for the 55E... That's right, the 550L with the petcock that fits perfectly on a 550E. Somebody must be slipping "stupid pills" into my coffee when I'm not looking.

Anyway, I swapped petcocks and installed the airbox I got from Cowboyup, and the damned thing runs great now! Yee-friggin'-haw!

I've come to realize that there are (at least) 2 different petcock types that Suzuki put on these machines. They look nearly identical, but the one on my 550E was the type that DOES NOT have a "prime" position. At first glance, you can't tell the 2 apart, but upon further inspection, one type has the letters "pri" stamped into the spring retaining clip, the other type does not, and the lever will not go to that position without the aid of a large pipe wrench. Don't even try. Also, the fuel line spout for the "prime" petcock points toward the seat, and the other version has the spout pointing toward the engine.

I'm going to spend today swapping the brakes, as mine are completely seized, both front & rear.

In case anyone out there reading this is unaware, this particular 1980 GS550E has spent the last 9 or 10 years sitting abandoned out in the weather, without so much as a ragged tarp to protect it from the elements. Southwestern Pennsylvania weather deals out a "full cycle" of weather... cold rain & snow in fall, winter and early spring, more rain in summer, with occasional decent riding weather sprinkled in between during all four seasons. Yes, even in the middle of winter!

I'm doing my best to get this classic Suzuki back on the road and in the wind. Wish me luck!

...and if you're wondering, the inside of the gas tank looks like brand-new. I can't say the same for the rest of the bike.

[cowboyup3371]

I'm glad that worked out for you