84 suzuki gs450l carbs problems

I have an 1984 Suzuki GS450L and I'm having some problems. From the reading
I've made on the net and here it seems it would be a carb problem. My bike
seems to stumble some times. At low RPMs it will stumble then take off and
if I keep it at around 4000 to 5000 it will seem like it's running out of
gas but then take off again. I installed a new air filter a while ago and
it seemed it was that because I replaced the old one and it stoped... well
for a while but now it's back and I don't know what to do anymore. Any help
will be appreciated. And if the carbs need adjusting I would like to know
how. Thank you in advance.

 

if you've never done carbs before, let a professional do it unless you are
willing to spend hours in front of a shop manual.

goto modern motorcycle. tell them to:
- clean the carbs
- sync the carbs
- install a gas filter
enjoy!

 

One more question before I send my bike in, how much is this gonna cost me?

Thanks

 

I had similar problems with an '86 GS550ES I bought that had been
sitting for several years.

The carbs were pretty crudded up. Lots of sediment in the bowls and
passages. Also, the slides were not sliding up and down nicely. This
is quite likely the cause of the stumble then take off problem. I
lapped the slides back into their bores which helped the beast run
much better. It still doesn't idle well when cold however.

Bob