Bill,
If your KLR is blowing BLACK smoke, you're definitely running rich.
Make sure that the choke enricher cable is properly seated in the
carb body and that the plastic elbow that mounts this cable to the
carb body is not broken. There should be about 1/8" of cable free-
play at the lever end of the cable when the enricher is in the OFF
position.
It's easy to check for proper float level by using a 8" clear
plastic tube that is hooked up to the float bowl drain fitting that
is located on the bottom of the float bowl. You hook up one end of
the tube to the fitting & hold the other end vertical, beside the
carb. Start your KLR, & hold it upright. Open the drain screw and
observe the fuel level in the plastic tube. The level should be 1/2
mm above the bottom edge of the carb body, where the float bowl seats
with the main carb body. All of this is shown in chapter 2 of the
KLR600 "base" manual. If the fuel level is too high, this leads to
an overly rich condition at all rpms. Possible problems could be
with the float adjustment or the float needle and/or its seat.
As others have suggested a torn diaphram could be causing your
problem. Make sure that the carb's slide moves up and down without
hanging up.
The carb needle can be replaced separately, as can all carb jets.
The needle seldom needs to be replaced, unless it is worn. This
only happens on very high mileage bikes, generally 40K miles or more.
You can easily eliminate the fuel tank & petcock as problem areas by
hooking up a small auxilliary gas tank.
Check out the carb rebuild info at
http://www.dualsportnews.com
Professor A9 Federal Way, WA. [USA]
-----------------------
--- Bill Lewis wrote:
> Thanks for the suggestion(s). When I first got the
> bike (got it used less than a year ago) basically the
> first thing I did was pay to have a complete tune up &
> carb cleaning & slapped new Avon Gripsters on. Later,
> that same shop replaced the floats because it was not
> running right. After bringing it there a 3rd time
> without them getting a good fix, I didn't want to go
> back (felt like they were soaking me by selling me
> more and more parts without REALLY trouble shooting
> the problem).
>
> Since then I've dinked around with some other possible
> fuel delivery things [snip]
>
> We ended up handing it over to a very competent
> Dominican MC mechanic friend of his {snip]
Basically, "la Maquina" got
> it running well enough for me to get it back down to
> where i park it -- its running real rough and real
> rich & is smoking a lot. Its not really in any shape
> to ride as a courier bike until this fuel delivery
> thing gets straightend out...
>
> If anybody has any ideas about what else might be
> going on, and if the "slap a new-or-rebuilt/salvaged
> carb in there" solution seems reasonable/unresonable,
> i'm all ears. I might not be able to fix it myself
> (if its anything more than about $20 that is), but
> since I'm trying to sell it (so I can pay rent), at
> least I can tell someone who might want to buy it what
> is likely to be involved with getting it running
> strong again.
>
> Sincerest Thanks,
> Bill
-------------------
KLR650Pilot replied:
> >> Hey Bill. Why don't you take the carb off and try a
> really good cleaning. If you have a better half you
> may want to ask for permission, but I would take the
> carb into my apt. or house and clean the carb really
> good. Clean the air filter also, and shell out just a
> couple bucks for a new plug. Chances are your problems
> will disappear. (Oh yeah, check the diaphragm really
> good for pin holes or breaks. If this manages to fix
> your problem, why not try and be a motorcycle courier
> in your city. Almost as good as a bicycle. Think about
>
> it. Sorry about the hard times, we've got them too.
>
> Jim, KLR650Pilot >>