Yea jet upwards till you peak and start to decline on the richer side. Then back up to the peak. You cant tell the peak till you have passed it, then you'd definitely know. Post your setup.
Sputter at opening throttle is likely pilot jet - but get the mains sorted first, like you noticed going up to 127.5 did affect that lower throttle opening as well.
Likely you end up with a much bigger main and hence have to drop down to a smaller pilot.
Set floats right - that is the first thing you need to do - then mains, then needle, then pilot then air screw.
Cool.
Buddha.

Took everything apart and put it back together again today.

First I found the vacuum hose on the carbs that goes to the left carb was leaking at the carb end.




Then I pulled the carbs and swapped the jets, now 132.5. Checked and the floats were on the low side so I adjusted them to be on the high side  I also fixed the airbox so it seals correctly, which in this case involved a combination of efforts. I heated it with a heat gun and wedged a block of wood inside to get the front face more flat/straight. Then I really worked the little rubber bell-mouth/boots so they fit right straight on the carbs with no gaps or misalignment at all, and cinched the hose clamps, THEN I worked the boots into the airbox from the inside of the airbox until they were sealed all around just right without disrupting the fit on the carbs. And THEN I put the airbox bolts in.

New air filter went in, a really slick UNI foam filter. Has a cool little rubber bell mouth inlet. I like this a lot. I now have UNI filters in both bikes! Plus foam & oil filters are supposed to be better for dust. I know a UNI flows better than a k&n and filters like a paper filter.

Put it all back with a new vacuum hose.

Speaking of both bikes, here's a pic...




Annnnnndddd.  Test ride, FIXED! Screams to 11.5k no sweat. It's a treat to ride! I don't know if it's my imagination or just the difference in better high rpm running making me more sensitive to it but I do sort of detect a touch of hesitation going from high rpm cruise (7+k) or decel to opening the throttle, but I haven't completely reset the pilot mixture so that might improve this. Just can't ride long enough to get it fully warmed up until either the govt gets off of this police state kick or I wind up having to take a "necessary" trip that's more than 20 minutes away.

My recent mods to the shifter mount and fork position are terrific. The bike is pretty much dialed now, at least as far as rideability. I need to hunt down some gravel to try out the new tires on non-pavement. I'm really itching to take it to my parents place in Castell with 10+ miles of gravel county roads behind 1.5 hours of country highways.

 

What tires are those ? Trailwings ? Those things are on my SCR, and 9K miles in they looks like new. Them tars wear forever.
Seriously I have 1/2 a mind to take the rear 17 off the bolt and put it on the GS and swap to the bolt mag's which are 15/19.

Try 135 just in case, But make good observations with 132.5. You really want to go richer than ideal and back up 1 step.

And looks like if they improve the flow in the head you need to get it richer.

Cool.
Buddha.

Shinko e705 150/70 rear and 120/70 front.

FYI, some more pictures. Here's the detail of the left side foot peg and shifter mount:



You can see the shoulder bolt that is holding the shift lever. That bolt happens to be an exhaust hanger bolt from my Triumph. If anyone is interested in building up these foot peg mounts like I did, I can look up the part number for the bolt and the shift lever I used.

Here's a view where you can see how I reinforced the shift mount.


I drilled and tapped an M6 hole in the frame and put an M6 bolt through the bracket to stiffen the mount. I used an M8 jam nut as a spacer, it was just more convenient than making one out of alu. The shifter is just about as solid as the stock shifter was, maybe a little more flexible, I can't remember. It is solid enough that you just ride without noticing any flex.

Here's the right side as it sits now:


I am going to be swapping the brake light switch for a banjo bolt ring sensor, part's on order. The brake light switch mount there is kind of temporary but it's really just not very reliable like this. It'll clean it up a lot, and remove that extension wire, to swap for the banjo bolt type. Incidentally, there's only about 5mm or so clearance between the banjo bolt and the swingarm so I can't use a whole banjo bolt replacement sensor like many other bikes have. That would require a different master cylinder with the banjo bolt axially oriented. With the stock MC I will have to see if the ring-type will work... this is one where the sensor looks like a ring terminal that fits under the existing banjo bolt head in place of a crush washer.

Here's my fork before I cleaned it, gives you an idea how much I lowered the legs in the triples:


After I swapped the tires and started riding the GS a lot more, I really noticed that it was pretty skittish handling-wise, but raising the front like this (about an extra 10mm more than before) basically cured it. I do think the weird handling was a combination of the tires rounder profile plus having the rear raised higher than the front steepening the head angle.

Just a full side shot showing a bunch of mods:


Here you can see my Rox-style risers which allow the bars to come back a couple of inches, which kind of makes up for the lack of pull back on these MX-style bars (KX-hi bend). The riding position is about halfway between standard dirt-bike and a "standard" like my Bonneville. Compared with my Bonneville, the pegs are about an inch lower and about 2 inches more forward, the grip-to-saddle distance is the same. The more forward pegs puts them right where they need to be to stand on them. With the bars and pegs like this it's easy to stand straight up on the pegs and ride around like a trials rider.

And BTW what I meant by "big" muffler is that it's like 2-1/4" inside diameter. It's probably 8" shorter than the stock muffler and being a perforated straight through large diameter, I think it's essentially nearly zero restriction. This muffler was made for a GSXR1000 and then after my bike was knocked over and it bent the can I chopped about 6" or more off of it. Yes, it's kind of loud, but not as loud as my Triumph with the 2-1 TEC exhaust with a full length cone silencer.

Managed to sneak out on a ride today to deliver some DVDs to my parents who don't have internet access at their place in the country, where they are heading to wait out the outbreak... anyway, it's a 9ish mile ride with suburban highway and neighborhood streets. Got to get a better feel for this jetting.

WOT once it's on it, it's great. But there definitely is a hesitation when coming from cruise at like 6-7k rpm and moving to accelerating. It's just a momentary sort of bogging and then it does its thing just like it should.

I'm thinking maybe it's time for me to shim the needles with one or two washers.

At least that'll give me something to do this weekend. Man I wish there was a way to do that without having to disconnect those fuel lines again.

Just caught up on your saga,.... screams to 11.5 was my favorite part   Good luck this weekend sir

Lean problems happen at steady state where it would try to lean surge. If it is lean, yea 1-2 washers is the answer. But keep an eye on WOT. It will get a shade richer - may not be enough to matter. You may still be on the leaner side of stoich. If it helps, it may be a thought to try 135.

Rich problems are soft response upon acceleration. I'm thinking you're rich a smidge there. If you're rich here assuming its 1/2 throttle - you may want to try 1-2 washers but dropping to 130. That would get you the same jetting at WOT as now but leaner at 1/2.

You also could have the slides rise too fast - which would be best served by training your wrist to open slower.

Cool.
Buddha.

Quote from: The Buddha on April 14, 2020, 08:02:14 AM
Lean problems happen at steady state where it would try to lean surge. If it is lean, yea 1-2 washers is the answer. But keep an eye on WOT. It will get a shade richer - may not be enough to matter. You may still be on the leaner side of stoich. If it helps, it may be a thought to try 135.

In theory it should not change mixture at WOT .. needle is all the way out of the jet.

This issue is, like if I'm riding at 5K rpm cruising at like 50mph in 5th gear, then I crack the throttle say from 1/8 (cruise) to 1/2, then it hesitates for about half a second before running just right to accelerate. However, if I ride straight through the gears at 1/2 throttle passing by 5-6k rpm on the way, there's no hesitation. So this is really a transitional thing. Also if I roll on the throttle slowly, no problem. I was thinking it also could be lean on pilot, maybe when I move the throttle it just takes a moment for the slide to come up and fuel to begin to flow through the main jet sufficient to accelerate. I haven't been able to reset the pilot mixture since the last round of mods.

Anyway, I'll fiddle with it. Totally rideable and usable now. Maybe I'll try it with the choke on and see if it improves or gets worse.

Incidentally, I did the throttle tube mod where you super glue in a piece of zip tie under the throttle cable to increase the diameter a bit and quicken the throttle opening. In all this just makes it easier to notice this problem.

The needle is still a tapered obstruction in the emulsion tube. The only way the lifting of the needle will not matter is if the needle like some DJ needles has no taper in that section. I've seen those guys cut needles that even have a step in them. So I have no idea WTH those would do. But a GS stock needle will always richen - in fact it will even richen idle, its tapered all the way across.
That's why they say get the mains right, then the needle then the pilot etc etc.

Cool.
Srinath.

well then it's entirely possible it's rich on pilot. I'll have to dial it in once I can ride long enough to get it well and warmed up.

Rich on pilot is going to want to stall as you try to take off, you really need to rev to 3-5k and never letting it drop below that.
Air screw only work at idle and to maybe 2K - at no load.
0-1/8th throttle is pilot. AKA - Take off.
How do Plugs look at idle.

Cool.
Srinath.

Added the pressure-sensor rear brake light switch. Wow!!! What an improvement over the stock piece of junk!

looks like this:


Here's the one I ordered:
https://www.amazon.com/gp/product/B07PMCDD69/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Talk about worth $9.

I did have to make little jumper wires with male & female spade connectors to it to make it work.

Quote from: mr72 on April 16, 2020, 07:53:55 AM
Added the pressure-sensor rear brake light switch. Wow!!! What an improvement over the stock piece of junk!

looks like this:


Here's the one I ordered:
https://www.amazon.com/gp/product/B07PMCDD69/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Talk about worth $9.

I did have to make little jumper wires with male & female spade connectors to it to make it work.

what does it improve?

Quote from: Meukowi on April 16, 2020, 08:40:45 AM
]what does it improve?

It switches on the brake light the moment you touch the pedal no matter how the brake is adjusted.

Dunno if you've tried adjusting that janky stock switch and spring bit if you have then you will appreciate the brilliant simplicity of this switch.

Additionally, for my bike, not having that spring and switch mechanism hanging in the breeze ready to snag on something if I'm riding through some brush is also a benefit.

Its bolted into the banjo bolt onto the pressure side ?
If that Chinese switch lasts as long as the corona virus in 3-4 months you might have brake failure - when you're hitting the brakes.

BTW there are some scooters that have this little metal can/bottle - about the side of a $2-3 worth of quarters that are supposedly ABS. I liberated a few out of some I found at the junkyard - have been just too terrified to slap it onto any of my bikes.

Cool.
Buddha.

Can't wait for the images to be reposted. 

The missing pictures are gone forever. Dunno where.

Quote from: adoptme on April 19, 2020, 11:20:49 AM
Can't wait for the images to be reposted. 

Those pictures are gone for good, but you can see everything you need to see in the picture in this post:
http://gstwins.com/gsboard/index.php?topic=71055.msg880846#msg880846

and also in pictures following if you want to see from the side.

Basically I cut the "nose" of the seat off so that it mates correctly with the '04 tank that's on mine. I reupholstered the entire seat. FWIW I also beefed up the foam with some closed-cell foam on the nose of the seat mostly because I was sliding forward too much and just needed to reshape it a bit. But it's very doable.

The '01+ seats will "wrap" around the little edges of the '01+ tank correctly but they are wider than the earlier seats. Also not 100% sure the seat will snap right in to the latch or mate correctly with the so-called "helmet lock" (the hidden hook for helmet D-ring). In all cases the '89-00 parts are much harder to find so that original '92 seat you have is probably worth a lot more than a '01+. I found that '01+ tanks were a dime a dozen, and I sold my dented/bent '92 tank for more than I paid for a mint '04 tank. Anyway, something to consider if only for a moment before you cut up the '92 seat pan. That's an irreversible mod. But I cut mine and have no regrets.

Here's a related anecdote. My Triumph's stock seat was horrid. Couldn't do more than about 45 minutes before I couldn't stand it anymore. I bought a Burton gel seat for it, a $400 custom job that took a couple of months to have made. It looks great and is way, way more comfortable than the stock seat, but still the GS is 2x as comfortable with my modified stock seat. I think it's not just the seat but also the more supple suspension even with my stiff springs. Point is, there's something halfway decent about those old GS500 seats. If I have to do a >3 hr ride I absolutely with ride the GS even with the 7k rpm on the highway and slightly squirelly tires just because the seat is that much more comfortable.

I'll second this ^^^ A lot of people like to winge and complain about the stock GS seat but its really not that bad. I wouldn't mind modifying mine a bit so it is a little more raised in the front to help me from sliding up on the gas tank haha, but overall the seat is great. I just went on a 3 hour ride last Saturday with a group of guys from school and there was a CBR600 F4i, an older Sportster 883, an Indian Scout, a Ninja 300, a z1000, and a really old VMax. The only ones not complaining were the guy on the Ninja and me haha everyone else was sore, had wrist pain or lower back pain and numb butts  . Incidentally, I was also one of the only ones who didn't need gas halfway through the trip. There are a lot of redeeming qualities to the GS and I think the seat is actually one of them.