I am the proud new owner of an 01 GS500 (my first bike). I realize its only a 487CC motor, but my bike seems really weak at low RPMS (less than 4k). The previous owner put a K&N air filter and a V&H Supersport muffler, and had the carb work done, but the bike is making a lot of soot and is *hard* to get warm. It almost seems like it is running lean at low RPMs, but rich at high RPMs.
Do these all sound like "normal" things, or does the carb jetting need some TLC ?
Normal, no. Jetting love, yes.
I would pull the carbs and look at the jetting job. Check the fuel mix, check diaphragm for tears. Look at your plugs...they are probably pretty sooty...rich condition. Let us know what you see when you get your carbs off.
If you want to be lazy you could try turning the fuel mixture screw in a half turn on each one and see if it makes a difference. If it still doesn't help try another half turn...when you start backfiring you know you've turned too far...backfiring is your carb screaming "I'm lean! I'm lean!!!" I would actually try the air mixture first...you never know...might be just the thing...
Quotemy bike seems really weak at low RPMS (less than 4k)
That sounds normal to me. Jetting problem or not, the GS500 does
NOT have a grunty bottom end. The engine needs 5k revs to wake up, and 7k+ to get serious.
That said, you definetly have some sort of fuel issue. I'm just echoing Dom here, but 1) check/replace plugs, 2) play with idle air screw, 3) tune the fuel mixture screws, 4) check air filter[clean?], 5) inspect intake boots[?], 6) disassemble/clean/rejet carbs, uhh......uh..That's all that comes off the top of my head.
If the previous owner had 'carb work done', did he do it himself? Did a shop do it? Did they do it
right?