O
octusis
Guest
Working on a '81 GS550L, Bike wont rev very high, and when its under load its even worse. I've cleaned carbs many of times and I can't figure out what it is any help would be much appreciated
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Does this bike, have stock airbox, and exhaust? And I have to ask, by "cleaned", exactly how are you cleaning them? How long have you had the bike? Is this a "all of a sudden" thing, or? More details on the history of the bike are needed. You have absolutely come to the right place for help with this bike.
OH! And welcome to the GSR !
For info there is a carb tutorial here http://zeus.mtsac.edu/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf
And yes welcome
. . . . . . . . . . . . . . . . . . . at looks like it will come in really handy. I guess I should look into buying a rebuild kit for it, any you would suggest? . . . . . . . . . . . . . . . . . .
...I would get stage 3 dyno jet kit, and an O-Ring set from Cycleorings.com.
These are the plugs if this helps, do these look too lean?Nobody here will suggest a rebuild kit here, lol. Straight pipes and pods will require more than 2 steps up in jet size. I would get stage 3 dyno jet kit, and an O-Ring set from Cycleorings.com He is a member here, and puts the o-ring kits together specifically for our bikes. Doesn't cost much either. the symptoms you have suggest a lean condition. VERY lean. If you follow the above cleaning and rebuild tutorial, you should be up and running long before we thaw out. Don't hesitate to ask questions. Only way to learn in my opinion...

These are the plugs if this helps, do these look too lean?
View attachment 59702
they look lean to me
One of the tricks to running straight pipes is to put "Lollypops" in the pipes to help generate some backpressure and reclaim that lost torque. Basically they're just a bolt with a washer welded onto them that's placed into the pipes. It's a cheap or even free solution out of a well stocked junk drawer. There's plenty of articles and YouTube videos out there on how to do it.
hey private message "chuck hahn" he knows about straightpipes and such but just know with straightpipes youll have to be tuning ur carbs a good amount of times no real set and forget tune for them. if ur not worried bout peak performance and like the loudness youll be fine but you do lose power from those straightpipes.
I have looked into them, I may try it tomorrow in my free time and report back. Do they tend to need adjustment or should I just run the washers straight vertical to the pipe?
If you're sure that the float needle is seated properly then you have two possibilities to look at. The first would be the seal that sits under the seat leaking, the second being the float height being off. From earlier in the thread it was suggested to get the oring set and do a proper cleaning following the tutorial and installing the jet kit. Anything short of that is going to keep you (and us) guessing and wasting your time.