Air box lid?!?!?

[Duane87]

just so im tracking. its ok to remove the air box cover and cover it with pany hose. i dont have to re jet my carb and ill be good?
im jumping around to alot of different threads getting all the info i can. im almost on info over load!!!
thats not a bad thing

 

[Blaaster]

just so im tracking. its ok to remove the air box cover and cover it with pany hose. i dont have to re jet my carb and ill be good? im jumping around to alot of different threads getting all the info i can. im almost on info over load!!!
thats not a bad thing

If you take the airbox lid off you need to increase the main at least one size, maybee 2.

You then should do a plug chop to confirm!

 

[Duane87]

i havent messed with "jetting" yet.
is that something a noob should try? i can use the hell out of a manual for instructions, but i have found that hands on with someone walking you through it is better

 

[doodleaddict]

jetting is easy it's just trial and error on the sizing which is why you need to plug chop but a nice thing is if you need to rejet just post with all your mods and chances are someone can give you a pretty well on jet size to use or try but plug chop is the only way to be 100%

 

[Duane87]

ok, i did read something about plug chopping. i will go back and read that thread and start there.

thx!

 

[Blaaster]

Plug chop.

Warm up motor to operating temp.

Fit new B8ES plug, ride through the gears and hold WOT in 5th or 6th gear for 10 seconds, or as long as you can safely.

Switch of the motor and pull in the clutch, roll to a stop.

Take the plug out and replace the old one for the ride home.

Carefully cut the threaded end off the plug to expose the insulator.

There should be a smoke ring of a cardboard or biscuit colour around the insulator.

If it is non existant or a very light colour, you are lean and require a larger main jet.

If it is a lot darker you are rich and may go down a size in main.

I prefer to run a little on the darker side, I may loose a little power but it is worth it for the peace of mind that I won't need a rebuild so soon.

 

[Duane87]

i will stop tomorrow get the plug you suggest and give it a try.

thx

 

[Quadrider10]

has anyone ever had any problem with removing your air box lid and hitting a puddle and water getting in...just a question thanks

YES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! if u remove the lid, do not ride in puddles!!!!! or do not hit them hard, and dont go throug anything deep! i thought i wouldent have any problems with removing it eaither, and i hit about 1" deep puddle of watter, at full throttle, and it got inside my carb, into the engine, and it broke the reeds costing me a race. dont go into puddles!!!!!!!!!!!!!!!!!!!!

 

[iLikeIke]

anybody come up with a "custom airbox" pantyhose and prefilter cover are too easy

 

[Triplecrown421]

i changed up my gearing abit and thought i would try removing the airbox lid to try and get every last bit of hp out of it and this is what i found out (i run stock carb)
blaaster is right it needed one size larger jet to keep with perfect mixture but i noticed more sound difference and 0hp gain or any feeling of improvment. i reinstalled the cover rejetted and the bike sounded quiter and felt the same.
i always have and now will recommend the lid

 

[blasterBruce]

I ran my stock blaster for 4 years with a few extra holes on the top of the lid and it helped with sound but did not notice and improvement in power or torque , More than likely Ill use a stock lid on my new build i have going , but it will be as close to stock as possible with only a few mods

 

[best]

Well, I do and I don't run an airbox lid.
My goal was to get through deep water with my Blaster. I wanted to take air from as high as I could get it.
Plus, I am running a KTM250 motocross engine with a 38mm carb. At full blast, I need air!
So I came up with this idea to use the seat as my airbox lid:

The black ring is a foam seal ring for a round paper filter.
You see the sheet aluminum that seals air and water off from below?
Air is now taken from under the tank cover and from the seat/tank junction.
There is a foam sealing ring around the edge of the seat to seal dust and water out.
It needs to be a very soft foam and have at least 1/2" crush due to seat movement.

These pictures were taken after a deep water event. You can see that water and mud still got into the airbox,
but it wasn't too bad, look at the inside edges of the filter box.

 

[iLikeIke]

the problem i have is lots of dust and lots of water at the same time well not really a problem but i can definetly tell when my filter gets plugged and prefilters save lives.

anyhow want to make something that breathes easy, doesnt suck in all the dust from the ground, and doesnt suck up water. or i just need to avoid ponds.. ha

 

[best]

the problem i have is lots of dust and lots of water at the same time well not really a problem but i can definetly tell when my filter gets plugged and prefilters save lives.

anyhow want to make something that breathes easy, doesnt suck in all the dust from the ground, and doesnt suck up water. or i just need to avoid ponds.. ha

The stock box works very well keeping water and dust out, only the rubber snorkle is kinda small.
Keep the lid, make a snorkle up larger than the carb and you will beat dust and water.
If your carb is the stock 26mm you only need a plastic tube about 1.25" inside diameter to do the trick.

 

[iLikeIke]

i will have to jimmy some sorta tube up im startin to think its jetted too rich by how it acts with a dirty filter need to cut a plug in half

 

[blasterBruce]

Yes a plug chop is needed to make sure jetting is safe or not , im new to jetting these lil monsters but im learning its not that hard

 

[Blaaster]

A correctly jetted motor will run rich with a filthy air filter.

 

[Hutch]

The stock lid takes very minimal power away, If its jetted right, itll run fine.

 

[iLikeIke]

The stock lid takes very minimal power away, If its jetted right, itll run fine.

true but this acts real bad.. hardly has any power swap air filters and bam.
just gota plug chop i guess not that ill change my jets anyway lol

 

[best]

I do not know the real reason the factory does this, I can only take some guesses, but I have seen restrictive air cleaner inlets on many vehicles over the years. It has the effect of giving good (and quiet) performance right up until maximum speed, and then it generally enriches the mixture to limit power and speed. A diesel rental van that I had was so bad you could not use passing gear at highway speeds, it would slow down. You had to back off the accelerator and let it upshift to gain speed. This 86 E350 had a restrictor spot welded (from the factory) inside the air cleaner. Remove it and WOW.

My guess is that it is a factory move to protect engines from full throttle damage at full load, high speeds and long duration use. Better for the engine to go rich and reduce power than burn up. The inlets in most cases including the Blaster show a careful calculated design to be very close to the carb sizing. In the case of the rental van (which I bought and owned by-the-way) you quickly learned to back off the throttle on the highway.

Most of the factory inlet baffles I have seen also had a significant effect of reducing inlet noise. This has the double effect of increasing the perceived power boost because you have an intake howl to go with a modest power gain.

The effect of a carefully designed restrictive inlet is a WOT fuel mixture curve that is lean(ish) up through the curve until maximum rpm, then richens considerably.

Maybe also this is the manufacturers way protect against jetting inconsistencies?
I don't know for sure, just some speculation...