'81 GS450 carb/fuel problems

[raerickson]

Now I've never dealt with carburators, which brings me to my problem which I need some help with. The bike started and ran decently when I bought it, but it certainly wasn't ideal and I'm fairly certain its going to need a GOOD carb cleaning and possibly even a rebuild.

With no air box or filters and a stock exhaust the bike would idle just fine. When given some gas it would rev up fine with no load, but under load it would cough and sputter. Once thouroughly warmed up (~20 min) it would get through that pretty good, but not great. Also, once warmed up, it would cough and sputter under load between ~4000 and 6000 rpm to the point where if I was at that point in the powerband and tried accelerating, nothing would happen.

So thats how it ran when I got it. It has since been parted out quite a bit in my garage and wont be started again for a few weeks at the least, but I'd like to do as much as I can before it starts to get put back together. Final product will have individual K&N cone filters and an fiberglass wrapped exhaust cut off right before the original muffler flaring begins. ( I realize this will be loud, and will probably not have as much power as running with the stock exhaust, but to each their own )

So the questions I have are what are some recommended jet settings as well as where I can buy a rebuild kit if I'll need it?

 

[Steve]

First of all, you don't want to buy "rebuild kits". They frequently contain sub-standard parts and most of them don't have all that you need, anyway.

Contact GSR member Robert Barr at cycleorings.com to get a set of o-rings for your carbs. Those o-rings and a can of carb dip is all you will likely need.

Jetting? Are they TRUE K&N filters or knock-offs? Yes, it makes a difference.
Anyway, with open exhaust

and pods, you will want to go about 7 or 8 sizes larger on the main, shim the needle about one notch and make sure the idle mixture adjustment screws are out about 3 turns.

.

 

[BassCliff]

Greetings and Salutations!!

Greetings and Salutations!!

Hi Mr. raerickson,

I concur with Mr. Steve. Follow the carb rebuild guide and use a set of O-rings from Robert Barr. It's usually best to get your bike running well in stock form before modifying it. That way you start with a baseline.

Anyway, 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

 

[raerickson]

Good to know about the no-no rebuild kits. I'll definatly pick up a set of the o-rings and I've already checked out the carb cleaning instructions.

Yes they are true K&N and not knockoffs.

Anyone have a reputable dealer to get some larger jets? I'm assuming they are model specific, right?

And yes, another person with open exhaust dreams. Love it or hate it, respect individuality.