GStwin.com GS500 Message Forum

Main Area => General GS500 Discussion => Topic started by: mass-hole on May 14, 2013, 11:56:18 AM

Title: Flat Spot in the RPM band
Post by: mass-hole on May 14, 2013, 11:56:18 AM
Hi,

I have a mysterious flat spot in the power band between ~4000-5000 rpms. Its fine above and below this rpm. Any hints as to what it might be?

Bike is bone stock from and engine perspective, stock intake, exhaust, jets, etc.

Thanks
Title: Re: Flat Spot in the RPM band
Post by: Kijona on May 14, 2013, 12:25:43 PM
What year

The pre 3-jet carbs were notorious for this

Change pilot jets to a #40 size It will make all the difference

http://www.youtube.com/watch?v=x5vidyo2_iw

Look how smoothly it idles and runs with the new jets

Contact Adidasguy for jets
Title: Re: Flat Spot in the RPM band
Post by: mass-hole on May 14, 2013, 12:30:00 PM
2000 so it is the older style carb. Thanks!
Title: Re: Flat Spot in the RPM band
Post by: bombsquad83 on May 14, 2013, 02:07:28 PM
Pilot jet can help some.  Also shimming up the slide needles can give just a bit more gas to the mixture in the mid range.  Use 1 or 2 small washers under e-clip on the needles.
Title: Re: Flat Spot in the RPM band
Post by: Kijona on May 15, 2013, 06:27:46 PM
Quote from: bombsquad83 on May 14, 2013, 02:07:28 PM
Pilot jet can help some.  Also shimming up the slide needles can give just a bit more gas to the mixture in the mid range.  Use 1 or 2 small washers under e-clip on the needles.

When modifying your carburetors it's best to take it one step at a time. I did just the #40 jet and was completely satisfied. Just sayin' :)