'74 GT550 carb questions

[vdavidoff]

Hi,

I just picked up a 1974 GT550 as my first project bike. Right now my goal is to get it running. I think I have a long way to go. I have dug through the forums and can't find answers to the following questions, and would appreciate it if someone could help me out. I have attached pictures to help illustrate my questions.

1) Looking at the carbs, there's a T connector between them that I think is connected to hoses that are part of the choke system. The middle part of the Ts have hoses connected that run nowhere, and I imagine they should be connected somewhere. Where do they go?

2) On the left side of the left side carb, there's what appears to be a place where a hose could connect. Does anything actually connect there? Seems like "yes".

3) There are small nipples on the bottom of each carb that have nothing connected to them. I am guessing these are overflow for the bowl, and I should connect hoses that would just hang there, allowing the bowls to overflow out into the world if they needed to for some reason. Is that correct? If not, how should these be connected?

Bonus question: Is it correct that these bikes will run even if the battery is dead, since we can kick start them?

Thanks for any help you can provide, and apologies if I these answers are already buried in the forum and I missed them in my searches. I know they're pretty basic but I am having some trouble finding assembly detail (even with the online manual).

Andy

[Madbuffalo]

Andy,

Welcome to the forum! I did my best to answer your questions but I have a GT750 personally so others may be able to shed more light for you. Post some pics of your bike if you get a chance.

1) T-Connectors: These are air vents that allow air to exit the bowls when fuel goes into the carbs and vice versa. They appear to be connected correctly.

2) Connector on left side of left carb: If you look at the center and right carbs they should have this same connector only the factory has drilled them out to accept the T-connectors. The far left one is a dumby since no T-connector is needed there.

3) Float bowl nipples: Yes, these are overflows. They should have lines that run down to between the engine case and swingarm that direct fuel away from the bike onto the ground.

Bonus Question) Starting with dead battery: The bike will not start with a dead battery. The GT electrical system uses a field coil that depends on a small current from the battery to create a larger current that the bike runs on.

From your pictures it looks like your carb intakes are fairly dirty and depending on how long your bike sat the insides could be just as bad. If you end up taking the carbs apart to clean them just be careful to record any adjustment screw positions first. The air screw position is especially important to know and will give you a good starting point, along with the factory specs, when fine tuning the carbs later. Hope that helps. Good luck!

Josh

[Cliff]

http://www.3cyl.com/mraxl/gt/manuals/su ... /cover.htm" onclick="window.open(this.href);return false;
The above link has some good info in it.

[Scorch]

hi vdavid! Welcome to the forum. These guys know everything about GTs, you'll have your 550 running in no time. Here's a link to the carb manual.
download/file.php?id=34" onclick="window.open(this.href);return false;


Cliff, not sure what happened but when I click on your link, Norton A/V gets in my face with warnings.
http://safeweb.norton.com/report/show?u ... S&pid=1122" onclick="window.open(this.href);return false;

[vdavidoff]

Thanks for the information, guys.

I disassembled the carbs tonight and unfortunately things aren't looking good. The float bowls of two of them are covered in white corrosion. What is more of a bummer though is that one of the pilot jets is clogged and seized, and another one came out but is clogged. I think the 3rd might be okay, but it's probably got corrosion inside it.

The bike came with another set of carbs, but unfortunately they were far worse off, to the point that the throttle valves are rusted into the carbs. They were all totally covered in white corrosion and rust. I was able to get a pilot jet out of one of them, but it appears clogged up, too. I am hoping that between the two sets I can build one solid set, but at the moment I'm not sure.

It is safe to assume it'd be smarter to buy new parts (like the jets) from Suzuki than it would be to see if I can get these cleaned up? I am concerned that something as small as the channel in a jet might never come back right after such corrosion, not to mention my inability to actually confirm whether it has or not other than if I can see light through it/pass fluid through it.

Andy

[Coyote]

The white corrosion will come out if you fill the bowls with Lime-Away. Vinegar will work too but takes a lot longer.
I was successful once at drilling out a seized pilot jet on a GT750 carb. I used a 3mm drill and drilled just deep enough to where the jet necks down to where the cross holes are. With tweezers, I unwound what was left of the thread. The rest just fell out after that.

[vdavidoff]

I took the carbs into a local shop that works on this kind of bike and was told that on 2 of the 3 carbs the corrosion was so bad that although i could work to clean them, they'd likely never run right. It was suggested that I find a cleaner set, which I think is what I'll be doing.

As far as the stripped pilot jet, I tried to drill it out and use an extractor but there's still brass in the seat. The same shop I spoke to about the carbs in general said they thought they could get the rest of the jet out, but I'm holding off on it until I know if I'm going to be buying a new set of carbs anyway. They also said it's likely that, even if nothing is leaking now, that the crank seals are hard and will likely need to be replaced shortly after the bike starts running again, if I get it to that point. But we'll see.

I'm going to pull the head and cylinders today or tomorrow before I get too much deeper into this.

Thanks again for the info, all.
Andy

[deerstud]

Hi
I purchased another set of carbs off ebay to use and between the 6 I was able to succeed in making a working set. The replacement set had good boots on it and that made it worth the cost as those are kind of pricey. I purchased factory jets from Dennis Kirk - very reasonable. Keep a watch out for a parts bike. That's what I did and it saved big money.