I am about to order a lunchbox air filter for my GS, do i need to rejet for this? if so what do i need to get? itll be a DIY thing, so if i need to rejet from stock, what do i need having just put in a lunchbox filter?  Thanks in advance for any help.

Rejet?  Possibly, but maybe not.  You're only giving us the title to a book.

Where do you live (elevation)?  Any other modifications?  Are the carburetors stock?  What year GS?  Does it run propperly now? ...etc...

in addition to what mak said, also stock or aftermarket exhaust? or if stock were baffles punched?

IMHO, yes. From reading lots and lots of jetting posts and what ends up working, you get the definite impresson that switching to a luchbox or pods makes more difference to the flow on our bikes than exhaust changes. I'ts not so hard to believe when you hear the change iin sound.

No biggie, since it NEEDS rejetting anyway.

What year?

I'm currently running a lunchbox with stock exhaust- settings in the .sig.

Quote from: serbianstunna on August 21, 2006, 10:31:05 PM
I am about to order a lunchbox air filter for my GS, do i need to rejet for this? if so what do i need to get? itll be a DIY thing, so if i need to rejet from stock, what do i need having just put in a lunchbox filter?  Thanks in advance for any help.

http://cgi.stanford.edu/~sanjayd/gs500/Upgrades/AirFilter

scroll down to Lunchbox 

its a 97 stock everything right now, but am about to put in a lunchbox.  thanks for the link, but what jets do i need then?  and as or right now the bike will when warmed, idle at 3k then drop to where its supposed to be after a lil.  I live in milwaukee so reg. elevation.

If everything else is stock, considering your elevation, jetting likely won't be a serious issue with just the lunchbox.  Any other modifications and you will have to rejet.

Must rejet - 150 mains ... not 1 size, like 10 sizes.
Cool.
Srinath.

of course you'll have to rejet!
removing the airbox is a huge modification & you'll have to compensate by giving the bike A LOT more gas.

I put on pod filters which are very similar & if you dont rejet you'll be sluggish throughout the ENTIRE RPM range at each throttle position. simply put: the lunchbox is only half of the mod.

do a search
I started a thread about lunchbox/pod filter install w/ the stock exhaust a few months ago(except I searched 1st  ) . that might give you some idea of what you're getting into. your carbs are a little older so dont go by the jets listed in THAT thread, but do a search & your sizes will come up easily. there is a lot more info & feedback for rejetting on the older carbs that the newer ones.

Yeah, you'll be lean as all get out. Lack in response and the engin will actually run hotter as well. Rejet, it's good for it either way.

Ok, executive decision. Everyone rejet now!

  -Anti 

anyone know around what mileage id be getting with the new set up?

Quote from: makenzie71 on August 22, 2006, 02:19:07 PM
If everything else is stock, considering your elevation, jetting likely won't be a serious issue with just the lunchbox.  Any other modifications and you will have to rejet.

I had to rejet when I put my lunchbox filter on. Removing the airbox tends to cause at least a slight change in air/fuel mix.

At your altitude it'd almost be mandate...in mine it's not detrimental to anything.

milwaukie is a bit lower than I thought, though...I thought oregon was higher off the ground than that?  Oh well.  It'll probably be border-line problematic for him.

so I've been looking and researching more, and i see srinath said 150 mains while the wiki saiys 147.5 mains?  which is the safer route to go?

it's always safer to have too much fuel than not enough...

Ig6

Quote from: makenzie71 on August 22, 2006, 11:53:33 PM
At your altitude it'd almost be mandate...in mine it's not detrimental to anything.

milwaukie is a bit lower than I thought, though...I thought oregon was higher off the ground than that?  Oh well.  It'll probably be border-line problematic for him.

altitude has little-to-nothing to do with it for this mod. if you remove the airbox you MUST rejet to get the performance the filters offer. otherwise, instead of gaining a slight increase in HP, you're actually LOSING probably a significant amount if you dont rejet. the bike might sound cooler but will be a slug.

not to mention the longer warm-up times, the bike makes popping noises here and there, and running lean hurts the engine.

when riding the throttle wont be responsive and there will be big dips in the power all over the RPM range & throttle positions.

It caused me to lowside. it's no fun leaning the bike over near the edge of the tires with an erratic powerband. I had the bike leaned over pretty far, but wanted to go further to the edge of the tire. I roll on a little bit more throttle to get a steeper lean angle & all the sudden I hit a dip in the powerband when I needed MORE power. It sent me on my ass.


P.S: check the rejetting matrix in the FAQ section for your jet sizes.

He asked if he needed to rejet...it likely won't be necessary to do such a thing. I'm sure he already knows that without propper tuning he won't see the full benefit of any modification.  Telling someone that the necessity is lacking is far different from telling them that it's the best way.

Altitude has a LOT to do with jetting...I have an XJ with turn downs and OPEN carburetors that runs phenominally on the stock jetting here, but in houston I can't even get it to start.  How can you think altitude has nothing to do with it?

I live in the hills of PA. I have had my bike in Florida, North Carolina, Maryland, New York, New Jersey, ect. Many differences in elevation, no difference in performance. How do you explain that mak?

  -Anti 

stock bike with generic jetting.