Fouled plugs, stalls when trying to rev.

[Davis550L]

Hello, this is my first post. I've been reading a lot of posts and they really help. I bought my first bike a 79 GS550L for $250 and it's been sitting forever outside in wisconsin through winters and what not. I cleaned most of it up, it was filled with leaves and acorns and mother nature. I took off the carbs and cleaned the jets and the bowls. I didnt tear them down all the way, just removed the jets and cleaned them. Now i got it all back together, i'm using the stock airbox but I dont have an air filter so I stuffed some foam padding into the air box. The bike idles well and I can rev it a little bit when its warm, but my tach doesnt work at the moment so I dont know how high I am revving but sounds like 5-6K and then it stalls. And it blows black smoke out when revving. Spark plugs are pitch black. Now I already know i'm going to have to take the carbs apart and replace 0-rings and get different main jets. Just wondering if i'm on the right page.

[old_chopper]

Testing complete, the engine will fire up and runs. Now it's time to fix things correctly. Any adjustments you make now will be wrong when you correct all the things that need attention. Here is a list in no order and surely not complete:

• Thoroughly clean the carbs
• Replace all orings in the carbs and intake system
• Adjust the valves
• New plugs
• Fresh oil and filter
• New air filter (more important than you might guess)
• Lube cables
• Check brakes thoroughly
• Probably new tires
• Safety, safety, and safety

I know you want to hear it run great now but it's gonna take a little time and patience. These bikes are very touchy about having the correct flow/restriction with the intake and exhaust so an air filter is critical, or a rejet of the carbs.
Welcom to the worlds largest collection of GS knowledge and information!

[BassCliff]

Greetings and Salutations!!

Hi Mr. Davis550L,

In your "mega-welcome" are a couple of maintenance lists similar to Mr. old_chopper's suggestions. Performing the tasks on these lists will usher you into GS utopia if you take no shortcuts. Let's get started.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[Davis550L]

ok runs good now. I can rev good through the whole rpm band when in neutral but when im driving and give it full throttle it sputters. Not like a bogging down sputter but sounds like it would be hitting a "rev limiter" if there was one.

[BassCliff]

Hi,

What maintenance tasks have you performed on the bike?



Thank you for your indulgence,

BassCliff

[Davis550L]

new plugs, air filter, oil, cleaned carbs and dipped, cleaned gas tank and petcock