Hi Guys,

New here.  Bought a 2002 GS500 for my wife to learn on.  Nice bike.  One of the upgrades I planned was to fix the lean jetting, so I bought the Factory Pro kit S11 as per their instructions on the website.  Installed it yesterday and the jetting just seems WAY off.  The bike has a stock exhaust pipe and a UNI filter in the stock airbox. 

My stock jets were 17.5 pilots, 60 mid jets, and 127.5 mains with the fuel screws at 2 turns out.

I installed the pilots (22.5) that came with the kit, and the smallest mains (137.5) that came with it.  The needle from the kit was set in the second clip position (from the top) as recommended.  The fuel screws were set at 3 turns out as recommended.

The bike idles ok, but "chuffs" every 20 seconds or so.  It will barely take throttle from idle up to about 4000 rpm.  Once it gets to that point it will clear out and run ok as revs get higher, but I suspect it's a bit rich on the main as it revs out.

My take on this is that this jet kit is just way to rich, especially on the needle and the pilot, and likely on the main also.  I noticed on here that most recommend going up one step on the jets and shim the stock needle.  This kit goes way beyond that.  Anyone have any experience with these kits?  I'm now thinking I should do it myself with the one-step-up recommended by folks here, and I wasted my money on this jet kit.

Thanks for any comments!

Needle is an obstruction in the emulsion tube.
The main jet is the metered orifice feeding in gas to the emulsion tube.

Cut a fat needle and you need a larger main to send in the same amount of gas. Factory could have done this and caused it to run perfect. Apparently, they cut the needles a bit too skinny.

DJ typically run a thin needle and put in 118 jets. Opposite of what factory seems to have done.

22.5 is rather much anyway for pilot.

The way back out IMHO for you, yea 20 pilot (your under 4K wash out is this, what throttle position, idle to 1/8th ? yea pilot too rich), but you could run progressively smaller mains till you like it.

Or of course the stock needles, 130 and 20's work well. Air screws to 3 ... why you have it to 2 ? did they recomend that ? Possibly cos they know they're over cooking it.

How are your floats, looks like factory knew atleast part of the game. If your floats were high, you may have the problem you're describing. It will repeat itself in a slightly different way even with my jets. You need to set all of the adjustments to the narrow range prescribed. Then fine tune it out from there.

PM sent too, just that you had more detail in this post so I decided to add my thoughts here where it has context.

Cool.
Buddha.

Thanks Buddha.

Yeah, as I was installing the kit I was thinking that two steps up on the pilot and 4 steps up on the mains was way more than I'd try if I were doing it myself.  Don't know how their needle compares to the stock, but suspect it's much skinnier (richer). 

Yes, I carefully set the float height as they recommended - to 14 mm.  I double checked it.

The jets in it were I think the stock sizes.  Someone had drilled the brass covers off the fuel screws, so don't know if the 2 turns out as the bike came is the stock setting or not.  The kit recommended 3 turns out, as I recall, and that's where I set it.  Perhaps I could try shutting the fuel screws down some and putting the needle clip in the top position.....

It actually burbles and stumbles all the way up to 1/2 throttle, only then and about 4000 rpm does it clear up and run ok.

As I said, I'm sure this jet kit just completely overshoots the settings I need.  Maybe with the stock airbox removed and a aftermarket pipe it would be closer. 

Yea OK skinny needle + 137.5 mains = major rich wash out.

BTW you can run it so rich it washes the lubrication clean off the cylinder walls and causes it to seize. Rare, but can happen. I would go back to stock ... or atleast park the bike till you get it close to correct. You people in warm climes are a little nutty sometimes.

I'd do +1 from stock as you know.

Cool.
Buddha.