Rejetting question (main jet only 115)

[domas]

Hi,

I have a 2001 GS500 UK model. I opened the carbs and saw that main jets are only 115 in size, while US bikes come 127.5 in stock. Are the bikes carbs different or is this just an issue of emmission?

Also is moving the Jet Needle E-clip has the same effect as adding washers? Which is better if so?

I have full aftermarket exhaust and a K&N drop in filter in stock airbox. My bike is restricted to 33 BHP. Could this be the reason i didn't run lean with 115 main jets?

I just dont get why is US and UK model jetting so different. Everyone says go up one size on mains. Would that mean one size for US and 5-6 sizes for UK?

Thx for any ideas.

[scratch]

The carburetors did change for '01+ models all over the world.  http://gstwins.com/gsboard/index.php?topic=12928.msg108863#msg108863

Moving the clip is the same as adding washers.

Full exhaust and drop-in K&N would make it leaner.  I'm not sure if the restrictor causes it to be more lean.  I suspect the smaller mains are a part of the restrictor kit.

Fortuneately, jetting formulas and sizes are the same across the globe.  The manufacturer jets bikes destined for particular regions, and for emission and legal reasons.

[domas]

Thx scratch ) 

[makenzie71]

Hi,

I have a 2001 GS500 UK model. I opened the carbs and saw that main jets are only 115 in size, while US bikes come 127.5 in stock. Are the bikes carbs different or is this just an issue of emmission?

Also is moving the Jet Needle E-clip has the same effect as adding washers? Which is better if so?

I have full aftermarket exhaust and a K&N drop in filter in stock airbox. My bike is restricted to 33 BHP. Could this be the reason i didn't run lean with 115 main jets?

I just dont get why is US and UK model jetting so different. Everyone says go up one size on mains. Would that mean one size for US and 5-6 sizes for UK?

Thx for any ideas.

The restrictor is why you're not running lean as is, and why they're jetted differently.  Your bike's breathing abillity is severely dampened to limit the possible power production.  De-restrict it and drop in 135's, at least, and tweak the pilot/idle a bit and you'll be riding a whole new bike.