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The Ultimate Carb tunning aid !!!......250 Main Jet anyone?????

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First off...i would like to say that i have been quite busy for the last little while, so i haven't been posting for a bit.Hope you guys find what i'm about to say below helpful :lol:.The mod i did below ,was done already two years ago and although i don't use it regularly now,i still put it on when i need to sort some jetting issues.

Ok...here's the deal.When i first got the DJ kit,(and i did get it early on, as i kept bugging Dynojet when it would be

released) i proceded to install it exactly as per instructions,with snorkel still in place.The bike ran well on the street,but when i ventured into my favourite dual sport trails,the truth came out.. ..too rich now for slow riding and when the motor got hot :lol:.Got back onto the road...motor cooled down...back to nice jetting :lol:.

Got back home and decided to give DJ in Vegas a call since it was still early on the west coast.Explained to the tech what i was experiencing, and as usuall out came the "tape up your airfilter or remove filter temporarily" to see the difference.Well i knew it was rich offroad, so i told him." what about removing the airbox cover??"..he said ya ..give it a try.Went out behind my house ( where i have some trials) with the airbox cover removed.Same jetting still...WOW!!! :cry:....what a difference!!!! the bike pulled hard.Went onto the street for a bit....and now opposite is happening....too lean for the street!!

Didn't bother calling DJ back as i knew exactly what it needed now.I started thinking :cry: ..how can i have my cake and eat it to??. .i know...a controlable airflow.Closed for the street,and opened up in the dirt.

Here is what i am talking about below:





Now i want everyone to keep in mind that this mod is not for everyone.The reason being is that the cost of a replacement side panel is not cheap should you need to buy another one after you do this mod to get it back to stock. I believe Suzuki charges something like $150-170 Canadian for a replacement :lol:....and no...Acerbis and UFO do not make any!!

That being said , anyone willing to try this must keep in mind the cost.Of course you can keep the opening closed , if you don't want to buy a replacement later on.I did buy a replacement one that i use now.Here are some more pics to show how it was made.




You basically cut out the panel following the shape on the inside that presses against the airbox seal.You should leave that rib of material in the midle to allow for partial opening as seen in the pictures.This is so you can run the the cover part open or fully removed.The cover is made from my old OEM seat cover.Yes i can sew too :lol:....Grabbed the wifes sewing machine, and stitched up the cover with the needed velcro to attach to the panel.You need velcro all around the edges to stick to the panel, and you need some velcro on the outside corner , so you can peel it back for partial openings as seen in the picture.The mesh is stainless steel,and is held in the panel with some of that high strength automotive weather stripping.

Also keep in mind that i did this before i did the 3X3 airbox opening.Hence if this was done in conjunction with the enlarged airbox opening, you could go up pretty large in the main jet :cry:...maybe not exactly 250 as i mentioned above, probably cant get one that big, but you might need one with that much airflow now.I can't claim this idea to be anything new, as i saw Johnny Campbell's XR-650 run a similar setup years ago in the Baja 1000, but he only had the cutout with the mesh and it always stayed open.I wanted controllable airflow for mine, and this was a way i thought would work.Also i have noticed Burned ( Eddie ) runs extra holes in the side of his panel on i believe his supermotard, so this may be a good mod for supermotard machines where you might want a bigger main, but can't get the flow from the stock airbox.

One last thing..ignore those "DEATH WINGS".. :lol: you see on the bike now.I had taken some nice long road trips and needed a smoother ride..so back went on the Bridgestones...good street tire by the way.Also a 39 tooth sprocket i made is barely visible in the picture which i will talk about later, that gave me a top end just shy of 160km/hr or close to 100MPH !! :cry:

Oh..while i was taking the pictures of the airbox, i shot one of the stable of bikes in my garage.. :cry:


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it will take little or no more main jet.the restriction is the air boot,not the hole when its just a little bigger than 3x3.

my motors use less main jet than stock motors. :cry:

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I realize you are at altitude Eddie...this the reason you run smaller mains??..i know i was exagerating about 250 main :cry:..nobody would ever go that high..even at sea level.

Funny you mention the restriction is in the airboot, not the box anymore.KTM's have a straighter air boot, as the shock is offset giving the boot a straight shot to the carb.I have read this many times as it being an advantage on the KTM's. :cry:

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im am altitude.but what im saying is my bike uses smaller main jets than a stock bike also jetted for this elevation.

motor mods usaully use less fuel.

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