New Bike - New To Forum. Need some advice!

[Elijafir]

Hello!

My name is Eli and I just bought a '95 Suzuki GS500 ES.   It has ~26000 miles on it!  It's a great bike and I love it! I'm 6'1" and ~155lbs.   It has plenty of pulling power, it's light and easy to control, and it has no problem with our 75mph freeway speed limit here in Arizona.  Kind of... Here's the problem:

I commute ~50 miles to work and ~50 miles back home 5 days a week.  The first few days the bike ran flawlessly with no problems what so ever.  The other day on my way home it bogged out and stalled  (which can be a bit sketchy at 80mph on I-10.)  It took about 10 minutes before I could start it again.  It cruises about 6k rpm @ 75mph on the freeway..  generally if I keep it under 6k rpm it has no problems at all.  It has no problems around town exceeding 6k rpm.  The problem with going 70-75 mph is I'm getting passed by almost everyone and I'm scared to pass and then end up having the bike stall out.  A few times it has bogged down and I can keep it running but slow down to about 50-60mph before it acts normal again.  I have been lurking the board for a couple of days.. and thought the gas cap vent might have been the problem so i rode to work this morning with the cap open and it still bogged on me.. it didn't stall though.  The other thing I noticed is that it seems to happen after the gradual ~1000ft climb through the low mountain pass.  It didn't do it on my way home, but I was taking it easy (70-75.)  As far as I know it's all stock except for a K&N air filter.  On Monday I was planning on rebuilding the gas cap per the write-up in the FAQ section; cleaning out the gas tank; cleaning both pet cocks; replacing the fuel lines; installing an in-line fuel filter (or replacing if it has one?); cleaning out the carbs; replacing the spark plugs; checking the valves; and re-jetting it.  The spark plugs indicate it is running a bit lean.   I've never re-jetted a bike before.. I guess I want to do a 40 pilot, a 130 main, 2 #4 washers, and 3 turns?  A link to good write-ups with pics would be GREAT!   

Any advice would be most appreciated.  If it seems like what I plan to do WONT fix my problem please let me know!  I would hate to dump a bunch of time / money in to this thing and not fix the problem.  Thanks in advance. 

-Eli-

[Elijafir]

Oh yeah, I forgot to mention the bouncy tach.  It almost always "bounces" a couple hundred rpm.  at Idle it seems to bounce between 1200-1500.. cruising speeds it bounces less.. Is this normal or maybe just needs to clean out that magnet deal i was reading about? 

[johnny ro]

My $0.04.

All jetting and carb questions are most profitably addressed to Buddha. Then he simply sends whatever you need, for a pittance. Oddly, he does not accept gratuities. Doesn't hurt to broadcast the question, though.

With that many miles it needs all you mention and more. Proceed with cleanup and fixes.

Photo shoots with explanations are found with a quick search for each topic you mention. Check the Wiki site as well.

Good choice on the bike. And on riding where you ride. I am jealous, stuck in upper east coast city.

[tt_four]

Most problems on this bike can be fixed with a carb cleaning, especially when it's new to you. Mine had a problem between 5k and 6k rpm for a while, and it completely went away when I pulled the carbs and cleaned them. Aside from that, rejetting it should help. Having an aftermarket air filter on there will let more air flow through, which would make an already lean running bike(comes like that from the factory) run even more lean. A bigger jet should help. Mine's a 135 but I also have a different exhaust on it, so that changes things too.

[jeremy_nash]

sounds like fuel starvation due to the petcock.  do a search for fuel starvation and you should find your answer.  

[the mole]

What he said ^.
Sounds like it could be fuel starvation if it comes on after a while at high speed. Have you tried running it on 'prime' to see how it goes?
Also, try turning it off as soon as it dies on you next time (pull the clutch!) then coast to a stop and do a plug check.