Freer flowing exhaust AND filter? Who the hell is this numbskull that worked on your bike?

Why would you go down in pilot jet size when it's a common upgrade to make them BIGGER on stock bikes?

The way it works, if you haven't already figured out, everywhere else [read: not USA], the bikes came with #40 pilot jets. Due to emissions crud in the USA, Suzuki was forced to make them #37 or 37.5 jets which is bordering on too lean. #40 seems to be a heck of a lot better. The backfiring, hesitation...all of that is caused by your mixture being too lean. I would take the bike back to the shop and tell them that you want the correct jets installed. Or ask for them and put them in yourself.

Freer flowing exhaust and freer flowing filter = leans the mixture. The bikes come jetted extremely lean to begin with. Adding aftermarket filter/exhaust causes an even leaner condition. You need to go up to a #40 pilot, and a #140 main. The washers are optional. It's extremely easy to do if you just take your time and don't get ahead of yourself.

Ok, so I called the parts guy at the local suzuki shop and he may have the jets. He wanted to know if the pilot jets were fluted or fluid. I couldn't quite understand him. What exactly should I be asking for? Thanks again, guys. A bit nervous, but I think I can do this.

Never heard of that in reference to jets......or many other things. He should be able to pull up the type of jets on a computer. Stock type jets, except larger sizes.

The WIKI has the correct Mikuni jet part numbers 

Uh...he's asking YOU what the correct jets are? 

I'd go somewhere else. That's like a doctor asking you if you should be prescribed penicillin or doxycycline....

Duh!  The correct OEM jets are on the GS500 parts diagrams. Doesn't the dealer have that? 

And its all right here:

http://wiki.gstwins.com/index.php?n=Upgrades.Rejetting

Well, my dealership here are officially idiots. I called two indy shops and between the two, I may actually be able to get all the jets tonight. If not, I'm just ordering. One place has the mains for sure, but not the pilots. The other may have the pilots and is checking right now. If they have them, the bike will be apart in a few moments

No luck on the pilots. I just ordered a set of 140 and 147.5 mains and a set of 40 pilots from carbparts.com. It's a 1 day ground ship, so lets hope they get the order out today and I should have them tomorrow

Ok, need help real quick. I just took out the pilot jet that the shop had in there, and there are holes in the shaft while the new ones I got have none of these holes. Did I get the wrong jets or did they have the wrong jets in there?

I just went ahead and put in the new 40s. It is now blowing out white smoke from the exhaust and gas is leaking from somewhere. Last time this happened, it was the air box, but I no longer have one of those on there since I installed the lunchbox. I'm currently at 40 pilot, 140 mains, 2.5 turns out with 1 washer. I have a slipon exhaust from a victory and k&n lunchbox filter as upgrades. Any ideas? Was the 140 main overkill?

Anyone? The leak was coming from one of the gas lines. It was on snug, but not all the way up the nozzle. I put it up the rest of the way, and it seems to have stopped leaking.

There is still white smoke from the exhaust, however. Any ideas? I have my license test tomorrow morning and would like to be able to take this bike up there for it. Lets finish this off so I can start driving to work again

The pilot jet is the smaller of the two. IIRC the pilot jets do NOT have emulsion holes and only a single hole at the "tip" of the jet that is almost microscopic.

Are you sure it's smoke and not just condensation? Hold your hand in front of the exhaust and see if droplets form on your palm. Smoke is very wispy whereas condensation will just be like, well, steam...because that's what it is. It will not linger if it's condensation.

A video would be very helpful.

Thanks for the reply. It is cold and wet today, around 38f and raining. I'm not getting major water dropplets or anything when I put my hand over the exhaust, but the hand gets moist. I've let it run for about 5 minutes and took it around the block, but the smoke doesn't go away. Should I be good to take it to the test tomorrow? The hesitation from 1st gear seems to be gone now as well. I'll post a video to youtube in a few minutes.

http://www.youtube.com/watch?v=KK1Yiw0txtI

Here is the video. The smoke is actually white with no blue tint. I had a buddy put his light down there so you could see it. Poor lighting in the garage.

Definitely condensation. I bet it doesn't linger at all, right? Just goes away immediately?

It's just your bike breathing

I think what you should do is wait for it to warm up outside, get the bike running and warmed up, and take it for a spin. If she seems alright, go for the test.

It did last night even after my ride around the block. Ran it until the engine was hot and it didn't go away. This morning, it was still coming out the pipe, but it lessened to almost nothing after about a 10 minute drive on the highway. It was around 35 this morning. I couldn't find my winter gloves, so I tried using a pair of leather carpenters gloves... yeah, that didn't work out too well. I ended up turning around after about 5 miles because my right hand was frozen. I have to wait until next saturday to take the test now.

So, this smoke is probably just condensation due to the cold/moist air? Other than that, the bike feels more responsive through the revs and first gear is riding nicely. The pilots I pulled out where 32.5 which looked like this part BS30/96 and the mains were 125s. I'm pretty damned upset at that shop. I should have known when I called the day it was ready and had to walk the technician through hooking up the last hose from the carb to the evap canister. Oh well, lesson learned.

Quote from: 00sanchez on April 21, 2012, 02:03:12 PM
It did last night even after my ride around the block. Ran it until the engine was hot and it didn't go away. This morning, it was still coming out the pipe, but it lessened to almost nothing after about a 10 minute drive on the highway. It was around 35 this morning. I couldn't find my winter gloves, so I tried using a pair of leather carpenters gloves... yeah, that didn't work out too well. I ended up turning around after about 5 miles because my right hand was frozen. I have to wait until next saturday to take the test now.

So, this smoke is probably just condensation due to the cold/moist air? Other than that, the bike feels more responsive through the revs and first gear is riding nicely. The pilots I pulled out where 32.5 which looked like this part BS30/96 and the mains were 125s. I'm pretty damned upset at that shop. I should have known when I called the day it was ready and had to walk the technician through hooking up the last hose from the carb to the evap canister. Oh well, lesson learned.

It's cold, so yes, it's most likely just condensation. I thought of something you can do to ease your mind. Start the bike, run it for a minute (until you see the "smoke"), then rev it up a few times and then immediately shut it off. Watch the end of the pipe - smoke will linger and slowly drift out of the pipe even after you shut it off. If it's condensation, the moment you shut the bike off, the "smoke" will go away. There'll be no trace of it.

Thanks, Kijona. I'll do that in the morning. I'm still seeing a bit of weirdness in 1st gear. The power seems to be hit and miss at WOT. Every other gear is fine. I haven't really tested the top end as it's been cold. Also, this may just be my having not been formally trained on a bike, but are you supposed to rev the engine up a bit and use the friction zone of the clutch in first gear on all take-offs? If I release the clutch in a car without much gas, I can still punch it and get the power, but on the bike, if I release the clutch without reving or using the friction zone, when the gear engages and I give it WOT, it will bog down for a second and then the power comes in. Is this normal or am I running rich on the pilot? Again, all other gears don't have this problem.

Normal.  You have very little power under 3000 rpm. 

I think you need to take it easier on the bike man. It's not a crotch rocket and WOT'ing from low RPM really lugs the motor. When I rode mine, and when I did WOT, it was only after the RPMs had gotten above 4.5-5K. You'll get better response that way AND it is easier on the motor. I don't think I ever WOT'ed in 1st gear though...way too jarring and hard on the chain, tires, everything.

Also, rolling the throttle instead of jamming it all the way open will give you better acceleration. The slides need a little bit of time (they lag every-so-slightly when you jerk the throttle open) to get moving. That's probably why there's a hesitation.