I've got a carb problem...original I know. Any help?

C

CaptainWyatt

New Member
I've got a 82 GS650 and some carb problems. It idles at around 1k or less. I have to bring that up with the fuel screw, I'm guessing. The main problem is that I can't get it to rev past 5k...and around 3k its sluggish. When I hold the throttle steady it doesn't stay revving steady...it drops then revs up, drops-revs and so on. I've sent seafoam through it and taken apart the bowls and cleaned. I also put pod filters on it so do I need to change my jetting? If so what do I do? Thanks.
 
Have you checked timing and compression? Also, any recent electrical changes like a new battery?
 
It sounds like a timing issue to me, especially if it gets worse while you're riding the bike.
 
It still could be a carb problem, but it's almost always better to rule out other things first. Any problems with timing and compression can definitely mask carb issues. Better to ensure those two things before messing with the carbs.
 
I really don't think its the timing or comp but I'll check. I messed with my air screw and it helped at a standstill. When I take it on the road it bogs and becomes shitty again. I have to choke it to run better so I'm assuming I have to still adjust the carbs. I'm thinking the pod filters and inconsistent airflow are the culprits messing up my air/fuel mixture. Does any of that make sense to the more learned people out there?
 
Carbs need to be cleaned and checked and if you are using pods, that would explain a lot. Try it round the block without air filters just to see if that changes anything. No dirt roads though :-)

Can you confirm what filters and carbs you have on that thing? Hint: pictures help
 
Bert Jan said:
please educate me on that ^
Click to expand...

If your timing is retarded then the spark that ignites the mixture comes in too late. The heat that should go toward expanding the gases in your cylinder and creating pressure to turn the crank is instead go out the exhaust.

At idle this often isn't too noticeable because not much power is needed to rev the bike up. It becomes more apparent when the bike is on the road because much more energy is needed to cause bike and rider to accelerate.

Peak cylinder pressure should occur at 14° ATDC. If it comes in too soon or too late, you'll be losing power.
 
That's all true, though 14 degrees is an approximation. To me, that doesn't really explain the symptoms he's describing which sound like idle is sort of OK but it won't pull and BTW needs choke to run. That last comment alone says clean the carbs first because there's a problem with fuel flow of some sort and that's where I would start.
 
maybe it's my lack of people skills but ...
three college degrees that I know of
at least 4 decades of motorcycle specific experience (possibly more )
AND
no one even mentioned valve adjustment

gawd almighty just killed a whole litter of kittens

~kop
 
To Kop's point, unless/until it has been properly serviced, we are just taking pot shots at what we think the OP is describing as symptoms. The starting point is to check plugs and ignition and carbs and valve adjustment etc

Grab a manual and start with a service. Fit fresh plugs and go from there. We are just throwing out possible issues, but it needs to be inspected and correctly adjusted first.
 
I don't have near the knowledge or talent that many have on here, but from dragging dozens of bikes out of peoples garages and backyards, when it comes to these symptoms, the thing that gave me the biggest payback is throttle shaft seals. many issues can be masked by other issues and it is imperative to get the bike to some kind of base, I.E. getting it to run and make adjustments from there. This is pretty much impossible if the carbs are sucking air from orifices that aren't made for that purpose. The shaft seal is probably the most over looked part of a bike, everybody heads straight for the jets. People will spend days and $ making adjustments and swapping jets etc. Here's the deal, if your bike ran fine with the jets it had, why would it all of a sudden not? Maybe the timing slipped, maybe the valves have finally come out of adjustment to make a difference, or if the change is sudden (fine one day and not the next) a seal is letting in copious amounts of air and screwing everything else up. I used to be that guy, making adjustments when my lack of experience took over. Once I had people show me how a carb. works, I found out, intake and seals were much more common fault than jets... Oh, and friggin needles, learning how to set these also makes life much easier...
 
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