DIY- Removing the Snorkel

[kkim]

Unless you are going to individual pods, which requires removing the airbox, the next best you can do is to open up that stock airbox. There is a snorkel that leads into the airbox that is used primarily for noise reduction. A discussion rolled around to removing it and after looking in the service manual, access to that snorkel, by removing the airbox, would be a royal PITA. Sigh, so much for that idea.

Or was it??? Tonight while doing something else on the bike I decided to take a closer look at how that snorkel was in the box and if it were possible to remove it without removing the entire airbox. Good news, boys and girls... there is.

Before I show you how, let me say that I have raised the needles in the carbs and as is the bike runs a step richer than stock. Removing the snorkel lets more air into the box by providing less restriction, meaning the bike will get more air and therefore run leaner. I bring this up only to caution that I do not know how your bike will take to this removal without jetting changes, but be warned... it could cause your bike to run too lean, which is not a good thing.

But, I will say, after I removed the snorkel, the bike idles even better, throttle response is improved and best of all, the bike now has an intake roar when revved that is very similar to putting an intake on a car. The hissing sound of of air being drawn into the motor at idle and when revved, a deep resonant howl is heard. Mind you, I have not even taken the bike out for a ride... this is only while idling and blipping the bike in my garage. Can't wait to hear it at redline.

For those that complain that the stock exhaust is too quiet, this is something you should look into.

Enough of the babbling... on to this easy, rewarding and free mod. One good thing about this mod is that if for some reason you don't like it, you can simply put the snorkel back into the place and the bike will be the same as before you took it off.

First, remove the airbox cover. Here I have the side cover and rear body panel already off. I was doing something else, so I don't know if you need to remove the rear body panel.
1.jpg

next, once cover is removed, this is the stock filter in place...
2.jpg

slide stock filter out. Remember which side of the panel faces the engine. you don't want to reinsert it later with the dirty side towards the engine.
3.jpg

Next, put your hand inside the airbox from where you removed the filter and push the snorkel back out the rear of the airbox. it is only pressed fit in there and has a weak glue around the outside edge for water proofing, I guess.
4.jpg

Here you can see the snorkel fully pushed out of the airbox.
5.jpg

pull snorkel out.
6.jpg

Position of snorkel when it was installed in the airbox before removal.
7.jpg

Hole in airbox after the snorkel removed. You now have that much more of an opening to draw air from.
8.jpg

this is what the inside of the snorkel looks like.
9.jpg

Reinsert your air filter with the clean side towards engine and put the airbox cover back on. I also have the rear body panel back on in this shot and it looks like you would not be able to get that snorkel out if you did not remove that rear body panel.
10.jpg

Bike all buttoned back up to show how the panels form an enclosure around the region where the air will now be directly drawn into the unrestricted airbox opening.
11.jpg

[M-Oorb]

Haha I move from one forum...kf...to a newer and better one...and why am i not suprised to see kkim still doing great posts...keep up the good work and spreading your knowledge

[kkim]

Originally Posted by M-Oorb

Haha I move from one forum...kf...to a newer and better one...and why am i not suprised to see kkim still doing great posts...keep up the good work and spreading your knowledge

lol... kf user name?

glad to have you here.

[M-Oorb]

moorbeek...pretty new to that forum too...got my 250 over the summer...but now I have a job and money and want to make my bike stand out from the rest so here I am...and im lovin it

[kkim]

Originally Posted by M-Oorb

moorbeek...pretty new to that forum too...got my 250 over the summer...but now I have a job and money and want to make my bike stand out from the rest so here I am...and im lovin it

cool... hope you will enjoy what this site has to offer.

[Sound Wave]

thanks for this great diy!

just did this "mod". i was able to do this with the rear fairings still on. the snorkel is pretty soft, so it works out pretty easily. whole process from beginning to end took about 5 mins.

haven't taken it for a ride, but it sounds SOOOO much better. planning on shimming it next weekend. that project kind of scares me.

[kkim]

yeah, it sounds better at idle and at WOT, but if you removed the snorkel before shimming, you may find the bike running a bit lean at about 5-8k... sort of jittery and not smooth through that rev range.

I'd recommend you shim as soon as practical. Be sure to use some 3mm washers... 2 of them under each needle to start with. You may need to go back in and take one out or put another in to fine tune.

[Sound Wave]

yeah, i should have waited and do them both together, but i was bored and didn't have time to do the shimming.

the 3mm washers... 3mm is the inner diameter hole i guess, huh? thanks

[GreezMunky]

I used 4mm when I shimmed mine. Any real difference between the 3mm and 4mm?

[kkim]

3mm is the hole size. I said 3mm as some have had problems when the 4mm washers they used was too wide overall and prevented the spring from seating properly in the slide. If yours works, I wouldn't worry about it.

The 4mm washers would be a bit thicker than the 3mm, I would imagine.

[GreezMunky]

Ah I gotcha Kkim. Thanks

[noche_caliente]

http://www.radioshack.com/product/in...ductId=2103391

Those washers are perfect!

[Sound Wave]

Originally Posted by kkim

yeah, it sounds better at idle and at WOT, but if you removed the snorkel before shimming, you may find the bike running a bit lean at about 5-8k... sort of jittery and not smooth through that rev range.

I'd recommend you shim as soon as practical. Be sure to use some 3mm washers... 2 of them under each needle to start with. You may need to go back in and take one out or put another in to fine tune.

ok, i am confirm that the bike runs like doo doo if the snorkel is removed prior to shimming.

i know you guys talked about it, but i couldn't believe that such a small thing would affect the air/fuel ratio that much.

[kkim]

now that you've shimmed and removed the snorkel, you'll be quite surprised at how smoothly the bike will pull all the way to redline.

when you have the chance, open her up and let her rip to redline and see for yourself.

exhaust next?

[Sound Wave]

well, i am still in the break-in period. i think i am at like 509 miles or something like that. i redlined it once or twice since i got it. i can't wait to hit 1000... it is torture trying to take it easy.

honestly, the exhaust sounds pretty good as it is. i think i may just paint it flat black for now and see how long that ties me over for.

[kkim]

lol... so you're the one following the factory break in procedure. Most do not.

There are many approaches to engine break in, but most use the hard break in method. http://faq.ninja250.org/wiki/Do_I_re...k-in_period%3F

More important, to me, is frequent oil and filter changes during the intial stages of your engines life. At your milage, I had changed the oil and filter 3 times.

You are perfectly fine to rev the bike up to redline. Just don't hold it there for extended periods of time. In fact, it's good for the engine for you to visit the redline on occasion.

My pipe, shimming and snorkel were on the bike a long time before my 600 service.

[Alex]

Originally Posted by kkim

My pipe, shimming and snorkel were on the bike a long time before my 600 service.

So that was 6 months in?

Alright, you bastages, with all of these pics and positive feedback from this & shimming, I may give this a shot this week as well. Not like there's a real need to make a red one any faster than it already is, but what the heck...

[kkim]

Best reason to shim would be to make the bike friendly at the bottom to midrange. Annie will love you for the change it brings. Isn't that reason enough?

So, shim it for her sake and pull out the snorkel for yours. The bike breathes a lot better up top w/o that restriction in there. That way, you'll only have to shim once.

if you don't like the change, it's completely reversible.

I'll have to check, but yes... I do think it was about 6 months in!

[Sound Wave]

Originally Posted by kkim

lol... so you're the one following the factory break in procedure. Most do not.

There are many approaches to engine break in, but most use the hard break in method. http://faq.ninja250.org/wiki/Do_I_re...k-in_period%3F....

oh, i am not strictly following the break-in... but i am following my salesperson's advice and not going "more than i need to".

thanks for that link btw.

[kkim]

I would interpret that salesman's advice to mean, ride it like you need to and ignore the break in procedure. If you follow the factory method, you become a hazard to navigation by going so slow.... especially on Oahu!!

[Alex]

Originally Posted by kkim

Annie will love you for the change it brings. Isn't that reason enough?

Annie thinks the bike is perfectly fine, and also thinks those complaining about the stock mid-range making it hard to pull away from a stop need to stop whining and learn better clutch and throttle control. She will also chastise me for going as far as taking the fairings off to make a small mod like this one that she's unlikely to notice or care about.

But I may do it anyway. Annie and I don't have to agree on everything.

My only concern is to make sure there's no way I go too lean at any point in the rev range. This bike spends virtually all of its time with the revs at 10k+, more often at full throttle than closed throttle. Which is why low to mid-range just isn't that big a deal in the scheme of things. But a less restrictive intake allowing more airflow at high revs, well, that does make intuitive sense to me, as long as there is also enough fuel at those same elevated revs. Shimming with a couple of washers just to make sure seems like a good idea at the same time. I can see why removing the snorkel without changing the fuel could be a problem, and the fact that that problem manifested itself in Sound Wave's bike pre-shimming is actually a good thing in my mind, as it partially confirms that yes, there was a change to the airflow that did have an effect.

[kkim]

Originally Posted by Alex

Annie and I don't have to agree on everything.

I see Annie and I might have a lot more in common than meets the eye.

Alex, not all bikes will respond to the shimming in the same way. You may have gotten one of the "good" ones that was set up a bit better from the factory than most. Usually those are the ones that warm up quickly from a cold start with little need of the choke. On the other hand, if yours does run lean, she'll notice the difference.

[Alex]

We'll see, you may be right. I use the choke to start the bike, I'm rolling within 15 seconds, and the choke is fully off by the time I get to the end of our residential street. The RRW article describing that Cary Andrews (AMA engine-builder) found the stock jetting to be almost spot-on, and even needing a slightly *smaller* main jet to optimize high-rpm power, well, that is also sticking in my mind as a data point that bears thinking about. On the other hand, going too rich causes a little worse fuel mileage, and potential plug fouling, and at some point a slight loss of power. While going too lean causes significantly elevated engine temps, and can lead to actual failure (in a number of different ways). So erring on one side or the other, it's pretty easy to choose which one as far as I can tell.

But, the upside to both of these is that they look to be easily reversible. If you can figure out how to mod it the first time, it's not rocket science to put it back if you simply don't feel a noticeable improvement, or even feel like you went backwards in usability or power.

[kkim]

yep, the 98 main is a bit large, but with the snorkel out, it leans it to work better at WOT. You can ask Richard how much better it runs at the track w/ the snorkel out. He was running w/ the snorkel in originally because he wasn't sure if taking it out was allowed. When they cleared it, he ran w/o it and noticed a higher top speed. This was back when his bike had stock jetting.

the shims will bring the midrange back that you lose taking the snorkel out due to it leaning out the midrange, too, plus enhance the off idle response.

try it... I'd be interested in what your take is on it. props to you for at least considering it. mpg will drop, though.

[Alex]

Originally Posted by kkim

mpg will drop, though.

I got 34 mpg on the Sunday Morning Ride this weekend. Not sure if it could drop any more. But it's not a huge concern, either. As long as the bike has 120+ mile range, that's good enough for me...

[kkim]

That's some pretty crappy mileage. You must be wringing it's neck in the lower/middle gears???

[Alex]

Originally Posted by kkim

You must be wringing it's neck in all gears???

Fixed.

I could save a lot of time and effort by just zip-tieing the throttle WFO from about 8 AM to 12 noon each Sunday. There's unfortunately very little exaggeration in that statement; basically the Marin roads that we go on allow, and encourage, full-throttle acceleration at all times. (this only applies to our Ninjettes, no promises if your bike of choice has 150+ hp instead of 25) There's really very little need or time for partial throttle application, only when you've reached the max speed you want to go on that particular stretch. But that stretch isn't particularly long, as most of the ride has appropriate twists and turns, so before you know it you're at full-throttle acceleration once again until you reach the desired end speed (which you may never reach).

It's terrifically fun. I've brought the ninjette a couple times the past few weeks, and loaned it out to friends. All of them were impressed with how much fun the darned thing is. One likened it to a great video game. "It's got all the noise, all the control inputs, all the feeling of riding a fun bike very quickly, but then you realize you're not going a million miles an hour". Several of them had also ridden our 2004 ninjette on the same route, and they felt the new one was significantly better from a handling, suspension, and braking standpoint.

[noche_caliente]

Alex - just another perspective on the snorkel - Nick had removed his with 2 washers in, and it made him too lean - he had to put it back - so another instance like Gary's, but more extreme....

[Alex]

Did he end up putting more washers on and then taking the snorkel back out, or did he just say the heck with it and left it in?

I gotta believe the snorkel isn't there as a decorative accessory. As we all know, a motor doesn't perform best when it has as much air as possible, it performs best when it has the correct amount of air/fuel when it needs it; extra air will hurt rather than help the cause. So I imagine rather than leaving a blank hole, kawi has the snorkel there to help the torque output somewhere along the curve; probably the midrange. And that's probably why when the snorkel gets yanked the midrange suffers, but at high revs, the extra airflow helps if there is enough fuel.

I guess for my purposes, shimming the needles alone doesn't really buy me much, so I'd only go down this path if there is a realizable gain when the bike is near redline. If as Kkim says, Richard noticed some more top speed with stock jetting and snorkel removed, well, that's what I'd want to hear. With you mentioning that 2 washers + snorkel left a poorly running bike for Nick that was still too lean, well, that's not what I'd hoped to hear.

[noche_caliente]

He put it back - we have a really variable climate here - was 60 on Sunday, snow Monday night through tomorrow, will be 60 again on Saturday.... has been single digit lows lately but summers can get over 100 at times....
I think his plan is to put another washer on and try pulling it again... compared to my bike, even with the snorkel it feel lean - I'm running two washers without the snorkel at the moment... I feel that mine is still a little bit lean as a result, but since my skills have improved in the time since I shimmed in the first place, it's not unmanageable
the only place I notice it is if I'm riding right at 6k - and that was only this past Sunday when it was warm - but since my tires were too low to make it to the gas station, I never actually left first- between the surging and the low tire pressures, I didn't feel safe at all and turned her around and went home - that said the surging I felt may be due to the tires as well - not enough experience yet to determine what the correlations are just yet.... enough rambling for you?

[g21-30]

Just my $.02, since I'm in the same weather situation. I pulled my snorkel at the same time that I replaced the needles with dynojet needles/clips on 3 rd position. The performance increase thru the entire range was verrry noticeable, with no hesitation anywhere. I left the OEM jets in place, as dynojet actually recommends their "smaller" jets.

You might consider spending the $80 for the kit and be done with it. Of course, check eBay. You may find a deal.

[voodoomaster]

Originally Posted by noche_caliente

http://www.radioshack.com/product/in...ductId=2103391

Those washers are perfect!

Which washers in this pack did you use and how many per slider?

[kkim]

If you are going to yank the snorkel, start with 2 washers under each needle.

Use the smallest washers whose hole is just big enough so the needles fit through.

It's not an exact science as washer thickness can vary and each bike's needs are a bit different from one another, so don't be surprised if you need to do this a few times to fine tune.

The best solution is to install a jet kit, but for pennies, this mod can't be beat to improve throttle response.

http://www.ninjette.org/forums/showthread.php?t=9465

[Sound Wave]

Originally Posted by voodoomaster

Which washers in this pack did you use and how many per slider?

it is going to be the second to the smallest size, #4. the smallest ones won't fit, those are #2.

[voodoomaster]

Originally Posted by kkim

If you are going to yank the snorkel, start with 2 washers under each needle.

Use the smallest washers whose hole is just big enough so the needles fit through.

It's not an exact science as washer thickness can vary and each bike's needs are a bit different from one another, so don't be surprised if you need to do this a few times to fine tune.

The best solution is to install a jet kit, but for pennies, this mod can't be beat to improve throttle response.

http://www.ninjette.org/forums/showthread.php?t=9465

ahhhh, I reckon the jet kit would have a nice matching set of washers. I concur that the washers from Radio Shack will be good enough...if I ever get big enough walnuts to dig into those carbs to do it.

[voodoomaster]

Originally Posted by Sound Wave

it is going to be the second to the smallest size, #4. the smallest ones won't fit, those are #2.

Thanks sound wave!

[kkim]

Originally Posted by voodoomaster

ahhhh, I reckon the jet kit would have a nice matching set of washers. I concur that the washers from Radio Shack will be good enough...if I ever get big enough walnuts to dig into those carbs to do it.

It's not as hard as it sounds, but you do want to work clean and orderly or, like everything else, things can go wrong. You sound like you've been around long enough that you know how to work smart.

I'm possibly showing komohana how to do this to his bike this weekend.

[voodoomaster]

Originally Posted by kkim

It's not as hard as it sounds, but you do want to work clean and orderly or, like everything else, things can go wrong. You sound like you've been around long enough that you know how to work smart.

I'm possibly showing komohana how to do this to his bike this weekend.

ALRIGHT...that does it. I'm just gonna have to hop an aluminum bird and come over for a few beers while i watch the operation... or better yet, a MOVIE of the operation would ROCK!

[kkim]

hmmm... maybe if we can, I'll take a vid of the important stuff. There's no way I can do a full DIY on vid of this... it takes too long time in terms of video.

[voodoomaster]

Originally Posted by kkim

hmmm... maybe if we can, I'll take a vid of the important stuff. There's no way I can do a full DIY on vid of this... it takes too long time in terms of video.

Oh yea, way to much video. I bet there would be a metric ton of us, those who have small pecans, that would get inspired by watching the actual digging into the tops of the carbs, the removal of the guts, and then the reinstallation phase.

Another detailed short movie of installing the tees into the CORRECT rubber hoses to enable carb syncing would also be valuable. With so many rubber lines, etc., down there, tackling that job the first time is ball-breaking as well. Having a CLEAR shot of which screws at the carb to turn to sync up the vacuum would be worth a case of Negro Modelo Gold (or Sam Adams Winter Lager for that matter ).


Anybody out there need a replacement kick stand or spring? Dude at work gave me one that appears to be in excellent condition. I don't need it, but why turn it down?