1st Gen O2 Sensor Placement.

[jra61]

Hello Bandit Alley,

My name's Jack (50yrs) from SW Ohio. I'm the proud owner of a 1999 Bandit GSF1200S(X) only 19,600mi, Stock, the color is Ubiquitous Black.This my 1st real post, even though I've been lurking and reading for months. There's a lot of valuable information here all I have to do is look for it, I couldn't find the answer to my question. I'm looking forward to Mods and Wrenching.

 Q. Regarding installation of an O2 Sensor on a 1st Gen bike. Could an O2 Sensor be installed in one of the (PAIRS) blocked off plates? Wouldn't some exhaust gasses work their way toward the Sensor? Any Ideas? 

[rider123]

What would be the purpose of an oxygen sensor? Are you trying to measure fuel/air mixture? These bikes are carburated, not fuel injected. If you want to do say a Dyno run with fuel/air mix the O2 sensor is usually done just inside the exhaust tail pipe. However if you want to have an accurate reading you should remove or at least block off the PAIR system so it doesn't screw up the sensor reading as it will register artifically lean with that stupid PAIR shit on there which is basically a factory exhaust leak. I'm not sure on the 1st Gen Bandit but on the 2nd Gen Bandit if you want to temporarily block off the PAIR to do a Dyno run you can clamp off the PAIR air input hose which comes from the airbox from the right side of the bike on the GEN2. I plan on removing that garbage next valve adjustment to kill alot of the deacceration popping and remove the crap from the top of the engine.

And welcome to the board!

It may help a bit if you could explain a little at what your trying to do, I'm sure someone here has done it.

[jra61]

Hi Rider123,

I knew I'd goof-up the question . You're right I'm doing a PAIRS-ectomy, and I have a set of SS plates. I've read too much, my thought was to braze a bung on one of those plates and install the O2 Sensor. I understand it's a good method to determine if the A/F is rich or lean. I have a background in Electronics I planned to monitor the readings via a Multimeter, get a base reading and use it as a comparison, I thought I'd get a truer reading at the headers. I think you may be right, at Ohio E-Check we just jammed a test probe up the tailpipe. I'm not trying to boost the horsepower just yet, just tweak for optimum performance. I just got a K&N SU-7593 air filter for $10 and I plan to drill out the EPA A/F Plugs.

[rider123]

Well for the PAIR shit, block off plates if they go on to the front of the engine just below the exhaust headers then it will work fine. Then you can remove all that PAIR crap, it kill about 5 pounds of crap and tubing and makes valve adjustments way easier to get to. It also eliminates most of the de-acceleration popping when putting on and aftermarket exhaust and some claim it to help idle and down low smoothness due to better exhaust scavaging. All the PAIR shit does is add air to the exhaust gasses to fool the emissions people there is less emissions then there really is. I wouldn't bother with it just get rid of it. Be sure to cap off any open holes that are created like the airbox and the vacuum line, etc.

 Do you want to permanently have an exhaust sensor installed on the bike? I'm not sure why you would want that but if you do you can either drill and tap a hole for the sensor after the collector box, either in the mid-pipe or near the end of the end can. Also if you're using the K&N filter without jetting for it, it will drive like shit. These bikes are already lean as hell out of the factory, with a K&N it's going to get even leaner. To make it function properly if the rest of the bike is stock you would need to go at least one up on the mainjets and adjust the mixture screws and probably add a shim or two to richen the needle. But if you're going to go to all that trouble you might as well just go to a stage 1 which will add 15 horsepower and drive alot better.

This is the best bang for your buck:(I have the next Gen so someone will have to check these jet numbers, going by Fast Larry's site)

Aftermarket end can with mid-pipe $150
127.5 Mainjets $12  type Mikuni N100/604
Radio shack shims for the needles part # 64-3022A $5
2" hole cut in the airbox lid, you can do it.
K&N filter, you already own it.
Mixture screws: 2.5 to 3 turns from lightly seated.


Horsepower gain 14-16 and a lot more grunt in the mid-range. Anything else to be honest is a waste of your time. Do not be tempted to pop on an aftermarket end can with mid-pipe without jetting or the K&N without jetting. You will actually LOSE power especially up top. Don't believe K&N's bullshit about just popping it on there and it's an instant 5 HP. The bike has to be jetted for any changes in throughput of air to the engine. Also do not buy an end can if also doesn't come with a mid-pipe. Since the mid-pipe is like %60 of the restriction of airflow on the bike some guys here have been saddled with an super expensive end can that does almost nothing because it didn't come with a mid-pipe.

If you're going to go to the trouble of popping off the carbs to drill the mixture screws you might as well wait until you can do a stage 1 at the same time. These bikes are stupidly easy to tune and you'll thank yourself later. This is a general guideline and should be confirmed by someone with a stage 1 on the Gen1 but this should get your close:

14.6mm float height(float height very important! make sure they are all set properly, mine were all over the place from the factory! Confirm with manual in downloads section)
2" additional  hole in the airbox lid
2 radio shack shims on the needles
2.5 to 3 turns out on the mixture screws
K&N filter
Aftermarket end can with mid-pipe

Recommended you swap out the soft brass float bowl screws with stainless steel hex bolts, makes changing jets stupidly easy. I believe they are called "M4" 6mm bolts but don't quote me. Just go to Home depot with a screw and match them up. If the aftermarket end can and mid pipe doesn't come with a centre stand stop you can fabricate one for a few bucks out of sheet metal. Some guys JB weld or drill and tap a hole in the top of the centre stand and glue or screw in a little rubber bumper. All these solutions are cheap. I can tell you what mine is if you like for my Muzzy. You can also buy a kit if you're not comfortable will jetting and they will give you help, such as Holeshot.

Here are some links to get you started:

Cheap exhaust and mid-pipe people are raving about out there:

http://www.dan-moto.com/DM_US/gsf-bandit-600-1200-n-s-wholesale-18_20_58.html

Doesn't come with a centre stand stop but if you have $3 in sheet metal you can make one like my Muzzy which attaches to the centre stand bolt. Or buy a fancy one for $30 at holeshot.

Holeshot stage 1 kit if you want the support:(pricey though your paying $150 for $12 in jets)

http://www.holeshot.com/bandit/bndt_b12_stage1mod.shtml

I know it's alot to take in but I would NOT install that K&N until it can be jetted. If you don't want to go to a full blown stage 1. Usually getting an aftermarket exhaust and using the stock filter with a jet or two up on the mainjets and a shim and a mixture screw adjustment will help you out alot. If you're going with the K&N as well you'd have to go up another 1 or 2, but at that point you might as well go to a stage 1. Since you're doing all the work for one why not have the extra 15 HP?


If you don't want to wait until you get all the parts you can get alot of improvement by drilling the mixture screws setting the float heights properly, setting the mixture screws the same(I think 2.5 or so) and if you want to try to pop in the K&N in there buy the radio shack shims and add 1 shim underneath the C-clip on the needles or the plastic spacer. That will get you pretty close though up top is still going to be pretty lean. Maybe do a poor mans carb sync as well:

http://forums.banditalley.net/index.php?topic=13207.0


Good luck!

[jra61]

Rider123,

WOW, Can't believe you went to this much effort for an ignorant newbie, you given me a lot of straight-forward no nonsense information,  .

OK, I'm going have to regroup. I'm going go ahead with a PAIRS-ectomy for now. With regard to the O2 Sensor I'll take your advice, there's no need for a permanent exhaust sensor. I'll rig an O2 Sensor on a fiberglass rod and shove it up the tailpipe when I'm testing.

Looks like I better start saving to buy a HS Stage One Kit with +5° timing advancer. I'm just hard-up enough I may consider trying the Poor Man's Stage One Mod and the Poor Man's +5° timing advance Mod. I hear great things about Dale Walker but I'm dirt poor and cheap, sounds like I could save over $100.00. I'll hold off on the K&N SU-7593 till I work on the carbs, and yeah I did buy the K&N propaganda, plus a reusable filter sounded good.

I already planned on getting a DanMoto S/N 96-06 EX281-BLK, but now it will be the last purchase when it was amongst the earlier mods.

I didn't see a lot carb overhaul information which included pics, do you recommend any site or thread that would helpful? What about Blades CD, does anyone know if it's good? The first thing I bought for this bike was a Shop Manual, Haynes Manual, and Microfiche. I plan on reading them front to back.

[jeffw]

 Shouldn't be a problem with the EX281, just make sure it gets supported well.
Blades CD is well worth the price, the procedures on it are performed on a Gen2 Bandit and clearly show what he's talking about. Most of the information is useful for a Gen1, as well.  They say a picture is worth a 1000 words, right? Well, that disk is probably like a million.

Be aware that the O2 sensor is probably going to be of limited value unless you are on the dyno, in which case, they should have one already.

[rider123]

Sure np, I know it's a lot to take in. If you want to just take a step back and think but get it running better a good carb sync is definately a step in the right direction. There is a .PDF of the haynes manual on this site in the "DOWNLOADS" section. Dales kits work really well and %90 of the time it's just plug and play. On my Gen2 though his settings were a little wonky. I was super rich down low and cruise and lean up top. So I put the stock pilots back in and went one up on the mainjet and voila, worked great. But you sound pretty competant so if you want to try it yourself, go right ahead. In hindsight thats what I should have done. I'm sure someone with a GEN1 bandit will pipe up here to help you out.

Heres a good site to get info, it's mostly for the GEN1 so you should be good:

http://www.portablepct.com/fastlarry/banditfaq.htm

I would be wary of the poor man's advancer trick until you've done everything else, because if you phuck up that timing plate......Might be better to get it running reallly well without it first then take some beer bottles back and pay the $40 for the Holeshot one.

I have the holeshot advancer and it does give a slightly better throttle response(true) and allegedly a  couple of horses in the mid range(dubious). But I'm sure there are just as many bikes without the advancer getting 115-118 horsepower with a homemade/jihad style stage 1 than with the advancer for like $12 in jets. If you want to go the cheap route I would try that first as there are a lot of guys here with GEN1 Bikes who have already gone through stage 1 and can help you for free. If it goes to hell you could always order the holeshot later. As far as the Dan moto go, I've heard them the smaller carbon fibre is pretty damn loud but sounds great. The triangular sounds just as good but not as obnoxious as you can fit more packing material in there. Just google "dan moto exhaust", there is literally dozens of videos so you can hear it for yourself. Either way it will sound better than the "sewing machine" stock exhaust and weigh 30 pounds less.

Cheapest route for you:

$130 dollar "Pride of the proletariat" Chicom Dan moto exhaust
$12 Mainjets (mikuni n100/604 size: 127.5)
$5 Radio shack shims part# 64-3022A
K&N Filter, you already have it
2" hole cut in airbox lid
2.5 to 3 turns out from lightly seated on the mixture screws
1 hour of work
$15 for beer


15-18 + horsepower. So if you can only drink 12 beers rather than 24 one night then you have the jets and shims for  a stage 1. Or you can pay for Dales kit at $150+ and have the support to tell you what you already know. Its up to you. HIs stuff is good quality. And there is nothing wrong with the K&N filters but you have to jet for them. Also you don't really need an Oxygen sensor to measure whether your rich or lean just look at the plugs. If you're unssure just post a pic of them here and we'll help you. Cost 0$



Super cheap bastard route:

Drill mixture plugs
1 radio shack shim
rest stock
raid your mums liquor cabinet

This will ofset a bit the horridly lean stock jetting and maybe a hp or two, but your mom will be pissed you stole her beer.

[sandy klock]

Greetings JRA61; welcome to site.  I have a narrow band o2 at the collector, mounted outbd to right side.  meters are cheap.  but you will need to get a heated sensor or wait for bike to heat up. great tuning tool.   good luck.   sandy

[jra61]

I have a narrow band o2 at the collector, mounted outbd to right side.  meters are cheap.  but you will need to get a heated sensor or wait for bike to heat up. great tuning tool.

Sandy,    Thanks for the greetings. I appreciate your giving a specific placement location for the sensor, that jives with the approximate location Rider123 was talking about. I already have a couple of multi-meters and a rough idea of the output somewhere between 200mV - 500mV depending on several variables. I still haven't ruled out mounting the sensor, I could attach a Bung at the collector, when not in use I could block off the bung with a bolt.  I still need to read-up on O2 sensors themselves, they're more than a simple thermocouple. Or, do you a recommendations, I don't mind heating up the bike before testing, that's what we did at Ohio E-Check before they went bust.

[rider123]

 It's probably best to put the sensor after the collector box so it takes a full reading from all the cylinders gasses mixed better. If you get an aftermarket mid-pipe it should be super easy to fabricate. Hell if you wanted it to be stealthy. A good 6 or 8 inches of mid-pipe is underneath the bike, you could mount it there and no one would see the sensor at all. Or you mount it out the outside with lasers and led's all over it your choice!  

[jra61]

I want to thank you guys here on Bandit, in specific Rider123 and Sandy Klock you both have been real helpful. That is exactly what I plan on doing, but I can still block-off the bung when not in use with a bolt. Right now, I've got to read-up on O2's sensors, also saving up to do that stage-1 you mentioned Rider.
 

[sandy klock]

 JRA; I have a mid pipe with hole for sensor. but there is a screen inside and it came apart. I will ship to ya if you want it. just reinburse for shipping.  what you do to get screen out is up to you.  I put sensor in collector on a aftermarket 4into1 that is actually a 4into2into1 due to a divider plate in collector.  sneekie way to get alittle torque back from 4 into 1 pipe. PM me your address if interested. central mi.  48818   sandy  good luck

[rider123]

Thats sounds like a good cheap plan if you want to go for it jra. A mid-pipe doesn't have to be fancy, just unrestricted. With your jet selection leave the insert out for now to test first. You can always just insert it later. Hell if I didn't throw out the horridly shit stock exhaust and mid-pipe one piece hernia maker I would have given it away as well as long as you signed a waver not to sue me if you drop it on your foot or lift it too much.