Own a 1996 LS 650.  Starts great and runs great after initial 10-15 minute driving period.  However, those first few minutes are a nightmare.  Pulling choke out immediately kills engine so not enough gas for warm up isn't the issue.  During the first 10-15 minutes, constantly have to pull in clutch and rev way up the engine to keep running.  No matter when, even once up and cruising in 2nd or 3rd gear, will continue to lose all power, but by pulling in clutch and opening throttle way up, works through it.  Then once ridden for 15 mintutes, again runs perfectly.  Been doing this for about a week now. Any thoughts on this issue?  Thank you much in advance.

have you checked your petcock?

Serowbot wrote on 08/05/13 at 11:11:58:


Would that be just for the first 10 min?? Just wondering for myself.

insguydr wrote on 08/05/13 at 10:30:21:


Three things to check --

First, is the tank full with FRESH gasoline, or are you using old gas to try to troubleshoot your issues?

Second, are you running a stock vac petcock?   What you describe falls into the range of things a failing vac petcock can do, but bad gas can also do some of the same things.

Finally, thirdly, charge your battery completely before every troubleshooting session -- battery discharge can creep up on you with all the cranking you are doing and when you get down below 11 volts your ignition stops firing very well (weak spark gives lots of false signals to you about carbs and gas and all sorts of possible issues)

Since mine was "new" to me at 7400 miles I have had to pull choke out to FIRST NOTCH for every cold crank and run a few minutes or a mile or so. I can use FULL CHOKE if it's below 50 or so, but only for a couple of minutes. That's just the nature of my beast. You didn't say if you use full choke or partial choke. Full choke gives just the symptoms yours has.

insguydr wrote on 08/06/13 at 12:08:38:


I give up.......What is a cold idle screw?