Initial Results: Carb Freshen and Re-Jet

[step]

Thought I'd post up, since no-one around here is interested - heh.

94 GS500E  Stock exhaust, air box, and air filter. 
Overall the bike is in very good condition with ~7k miles.

Pulled my carbs down to inspect and re-jet.   I had a slight hovering idle and a very noticeable flat spot around 4500 rpm.  Plus I just like to take stuff apart.

With the fine help from this forum, some downloaded service manuals, and the wiki, I had no big problems, and my efforts have yielded positive results.

I cleaned out the carbs with carb cleaner and compressed air.  I did not split them. I installed 40 pilots and 125 mains and one new needle spring seat.  Installed new bowl gaskets, float needle valves and seats, and a couple o-rings as found in the over-priced 'carb rebuild kits' that I felt compelled to buy.  Set the float levels per the manual.  I left the existing washers under the needle and set the idle mixes to 3 turns out (was around 3-1/2 or 4).  Other than the faulty spring seat, I saw no other problems and the idle mix plugs were already drilled out.

Challenges:

   
• Identifying that there was already a washer under the needle  ( I left it in, and did not add any more).
• Re-connecting all the hoses, even though I paid attention.  The extra battery drain hose was mis-leading and some of the other routing was wrong when I got the bike.  It was tedious, but I got them all connected and routed nicely.
• Incorrect/melted/dissolved needle spring seat that needed replaced - didn't see that one coming, but local dealer had one in stock for $3.
• Fishing out a dropped screw from the bottom of the shock casting - What a freaking PITA!!
• Fixing the rust on the frame and battery box from an ancient  leaking battry incident.

I rode the bike to work this morning and I am very pleased with the results.  I still think the idle should drop faster and the rev action should sound a little 'angrier' - BUT - the flat spot is gone!  Overall, bike seems to run a little better, but not really any drastic power increase.  No negative side effects at all.  No leaks, started well, and ran great.
More riding to come at lunchtime! 

Thanks for all the help and tips.
If you are thinking about re-jetting, I say go for it. 

[jestercinti]

Thanks for the post Step.  I plan to rejet my 2009 once I get the jets from Buddha.  I echo your comments...I learned a LOT so far from this board.  People are willing to help!

Glad things worked out.  I have a little hanging idle too.  Probably mine is just lean.  Can't wait for my rejet soon.

[step]

Jester, One of the firsts things I was told here, was to lower my idle speed to help with the hang and also to make sure the bike is completely warmed up before making adjustments.  That seemed to do more for the slow decel after a rev than anything else.  But! after the carb rebuild, she seems to like the low idle speed more than before.  I think the idle was so high in the first place to compensate for the bad carb set-up, so it is definitely improved in that regard.

And I stretched her legs a little further over my lunch hour.

In all fairness, I have to point out that the clogged air filter and bad spring seat were probably the main culprits for the poor performance, so this was not just a straight jet swap on a well-tuned bike....

But, I am definitely not disappointed.  As I mentioned, it seems to hold a 1200 rpm idle a lot better, with more smoothly-delivered power when pulling out from a dead stop.  Also, the top end feels less restricted, like it will keep winding out faster and faster, much more than before.   Seat-of-the-pants dyno tells me that the whole job was a really good thing to do, and that is my main point. 

I think the bad spring seat was letting the one needle creep up prematurely and the overly rich idle mix was also holding back the bottom end.  The mid and high RPMs benefited more from the jet swap.  And the new air filter helped everywhere.  Hahahahaa - I know everyone wants to think that their tweaks make a huge difference, but this really did work out well for me.