1978 gs550 wont pass 4000 rpms ???

[Jesse002100]

i recently got this bike and it wasn't running any kinda good, change plugs wires oil and battery. Now it seems like as soon as i hit 4000 rpm it bogs and then backfires acceleration is very slow as well. im new to these bikes. if anyone has any ideas and can give their thoughs i would greatly appreciate it.
Thanks in advanced, Jesse

[Larry D]

Welcome Jesse.
What do you know about the history of your bike ? Where are you on the planet ?

Cleaning/rebuilding the carbs and adjusting the valves are a right of passage for our vintage bikes. While your doing these two common maintenance issues, you'll learn much more about your bike and what it needs to run properly and safely.

Check out some of the topics on the homepage. The use of the search feature will unveil years of information.

Good Luck !!

[Mith]

Let's not forget the intake o-rings. When I replaced them on my GS550L they were completely flat causing big air leaks. Also replacing the airbox boots to the carbs made a huge difference. I couldn't keep a steady idle until I replaced them.

Good luck with your 550, I know I love mine!

Pete

[Suzuki_Don]

i recently got this bike and it wasn't running any kinda good, change plugs wires oil and battery. Now it seems like as soon as i hit 4000 rpm it bogs and then backfires acceleration is very slow as well. im new to these bikes. if anyone has any ideas and can give their thoughs i would greatly appreciate it.
Thanks in advanced, Jesse

First check the points and condensers. Get a workshop manual, it will tell you how to accomplish these tasks.

Also check the air filter foam to make sure it is not dirty and clogged. And follow the previous advice as well.

http://www.mtsac.edu/~cliff/storage/gs/GS550_Service_Manual.pdf

Download this manual if you can.

[SabreJim]

time it

right off it sounds like its out of timing, but it could be a combination of things.
Time it and see if you get your RPM's up....
I use an old turn signal with aligator clips on the wires to clip to the points and a ground point. TDC just as the light goes on for mine. You can also hit it with a timing light if you have one.

[Jesse002100]

right off it sounds like its out of timing, but it could be a combination of things.
Time it and see if you get your RPM's up....
I use an old turn signal with aligator clips on the wires to clip to the points and a ground point. TDC just as the light goes on for mine. You can also hit it with a timing light if you have one.

i just checked the timing on it and its perfect, a mechanic told me that its only a vaccume motor so maybe vaccume is the problem as one guy here said. is there any places in or near ohio that sells old parts for these?