Fuel problem maybe?

[screwlost42]

I own a 1980 GS 450. Great bike, love it. It seems to have a misfire when trying to maintain a constant RPM. I have taken the carbs off and cleaned them and checked the screens, floats and the diaphram and the petcock. Petcock did have a bit of trouble so I cleaned it and it is fine now. Put in new plugs. Checked spark seems fine. Bike has no trouble when you are giving it gas, but trying to maintain a constant speed is like flying through turbulant skys. A little choppy at idle, and after riding for a bit it will occasionaly stall at idle(think i just have to adjust the idle screw for the stalling). The main problem is the missfire. have read some similar posts, all replies talk about floats and petcocks, as I said checked these out and did not solve the issue. Any thoughts?

[BassCliff]

Greetings and Salutations!!

Hi Mr. screwlost42,

Adjusting the carbs on the 450 can be tricky. Make sure they are absolutely clean and have a new set of carb O-rings installed (see the proper procedure in your "mega-welcome" and get your supplies from www.cycleorings.com). Makre sure the float height is dead on. You might try raising the needles. Make sure there are no air leaks in the air intake system, including new intake boot O-rings, tightly sealed airbox, etc. Check that the gas cap is venting properly. Do you hear a sucking sound when you open the gas cap after a stall? You'll find more tips on my little website, like adjusting the mixture screw using the "highest idle" method. Now let me share some more GS lovin'.

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

[tom203]

I own a 1980 GS 450. Great bike, love it. It seems to have a misfire when trying to maintain a constant RPM. I have taken the carbs off and cleaned them and checked the screens, floats and the diaphram and the petcock. Petcock did have a bit of trouble so I cleaned it and it is fine now. Put in new plugs. Checked spark seems fine. Bike has no trouble when you are giving it gas, but trying to maintain a constant speed is like flying through turbulant skys. A little choppy at idle, and after riding for a bit it will occasionaly stall at idle(think i just have to adjust the idle screw for the stalling). The main problem is the missfire. have read some similar posts, all replies talk about floats and petcocks, as I said checked these out and did not solve the issue. Any thoughts?

Spend some time on Basscliff's site for some good info. Sounds like you have an intake air leak. Beware petcock repairs.