Page 1 of 1
Airbox mod and Jetting the Carb.
Posted: Fri Aug 14, 2009 11:19 am
by Major Redneck
After doing the Airbox mod,,, removing the rubber snorkel and drilling out the plastic the snorkel fit in I could tell the bike needed much more fuel...
After talking with the Tech at Charlotte Vespa he drilled me a .97 jet... After installing it I could tell right away the jet needed to be larger... Now with one jet in the bike and another one in hand I keep going up in steps drilling out the jet... The jet that worked well with my setup was a 1.2mm hole... the 1mm hole did well and after adding the 1.2mm jet it was just a little too much... I took the foam airfilter off of the airfilter and its just right... Now no more flutter/lugging/pooraccelaration,,,on slow takeoff to higher speed... plenty of fuel for all kinds of power,,, going up a hill it well now hold the speed much better as well as accelaration is were it should be...
If Rattler owners have not done the airbox rejetting mod they should... If they can not do it take it to the dealer to have them do it... its the cheapest and easy way iv found to get the Rattler to perform like it should... Still even with all that gas it well only hit 60-62mph indicated but runs very well all the way...
Posted: Fri Aug 14, 2009 1:29 pm
by B02S4
What size drill bit did you use for the snorkle opening?
Posted: Fri Aug 14, 2009 3:19 pm
by Major Redneck
I just took a large bit say 1/4" or larger and drilled out holes along the edge untill i was able to brake out the plastic... Then took a woodrasp and filed down the edges... Once this is done AIR moves much easyer,,,
Posted: Fri Aug 14, 2009 11:31 pm
by laxer
That's what I currently have until my LSS gets the right jets for the unifilter, there's a lot of power just waiting to come out of that 106cc 2T!
Posted: Sat Aug 15, 2009 1:37 am
by Major Redneck
With my semi-retired self and little to do,,, I played around today with the jets,,, I swaped back to the 1.mm and tryed it again,,, seem to have a little more on the topend than the 1.2mm jet... Put the 1.2mm back in and topend fell off a few mph as well as power on the topend,,, but takeoff was dead on the spot it just seem to lull at the 55-60mph even feathering did not help... I put the 1.mm back in and lull in the low end takeoff but was wide open topend was back at the 62mph,,, I did richen up the airmixture a little and I put the 1.2mm back in this time the lull was more noticeable on the topend,,, not enough air... But im not going futher on the airbox at this time,,, ill test again tomorrow I ran out of time today... I will swap back to the 1.mm on a cold engine and test at the airmixture setting i have now and see what i think then... I wish i had a 1.1mm bit but dont,,, that might be the sweet jet for this bike...
I can say this the power is way up with the larger jets,,, it well now out take my zuma 125 up to the 50mph mark... By far the Rattler is more funnest than the zuma to scoot around town...
Posted: Sat Aug 15, 2009 1:47 am
by B02S4
OK, so you basically took out the snorkle partition panel...
You might want to try a thin shim under the needle with that bastid 100 (1mm) jet.
Posted: Mon Aug 17, 2009 6:24 pm
by Major Redneck
B02S4 wrote:OK, so you basically took out the snorkle partition panel...
You might want to try a thin shim under the needle with that bastid 100 (1mm) jet.
Yes. I took out that whole part that the snorkel fits into... now rather a large opening... you can see the filter looking through that now large hole... When my camera gets out the shop ill post just what it looks like...
Today UPS dropped off a package with a 105,,,108,,,110 size jet at a cost of 9.95 each... I first installed the 110,,, and I think its right on the money after about 10 miles of testing & adjusting the airmixture... I well try the 105 and 108 at a later time,,, just cuz i can... With the 110 it runs very smooth with great pickup and even engine rpm across,, the most power seems to be at the mid rpm range that is about 30-40mph... Very windy day so topend will have to wait... I only weight in at 160lbs... The 120 i feel would work well if you road dubble all the time,,, or weighted in at over 250lbs... The 120 worked great under load...
Tip: I normaly after removeing the carb use the drain screw at the bottem and drain the gas out on some grass in the cracks of the parking lot before takeing the bowl cover off... This last time i did not do this i let the gas spill out as taking the bowl off just to check to see if trash was at the bottem... Yes there was trash as well as two small droplets of what looked to be water... (Water will sink to the bottem of the bowl) How it could have happend is by me working on it,,, true... The main reason that the carb has the drain is for that reason TO REMOVE TRASH AND MOSTURE THAT GET INTO THE FUEL SYSTEM not so much for the R&R of the carb itself... You folks that have that Redneck knowhow,,,take a paper towel and fold it somewhat small enough to fit under the carb. to catch the gas,,, open the drain screw at the bottem of the carb. bowl and let a few .oz of the fuel out the bowl every 3 months or so... Gas attracts mosture as it is cooler than air... Also SeaFoam well help in the removel of mosture from your tank and fuel line system... Iv got where i add one .oz of SeaFoam per tank of gas,,, Why every tank??? Easy,,, .oz of prevention is worth a pound of cure!!! Better tell the drunk Rednecks not to smoke or other flames close to where your working,,, Safety First...
Again if you dont know what you are doing by all means dont do it Stop!!! Find someone that does understand... If you think i could help please ask... If you brake it you buy it!!!
Posted: Tue Aug 18, 2009 1:35 am
by B02S4
MR, the best flowing setup out there is a Uni pod foam filter. I had a 115 main in the OEM carb & stock exhaust with that filter. By comparison, I ran a 120 main with a shimmed needle with the Uni pod & V8 Rattler exhaust. The motor was bone stock otherwise. I can't imagine on its best day that a modded airbox would need more than a 110 main with the stock paper filter & stock exhaust.
Posted: Tue Aug 18, 2009 12:18 pm
by Major Redneck
B02S4 wrote:MR, the best flowing setup out there is a Uni pod foam filter. I had a 115 main in the OEM carb & stock exhaust with that filter. By comparison, I ran a 120 main with a shimmed needle with the Uni pod & V8 Rattler exhaust. The motor was bone stock otherwise. I can't imagine on its best day that a modded airbox would need more than a 110 main with the stock paper filter & stock exhaust.
I think with the post above iv proved that a 120 is too large,,, the 100 is too small... To me the uni pod on a Rattler looks like a well dressed lady with cheap red toenail polish on...
Posted: Tue Aug 18, 2009 10:04 pm
by B02S4
Posted: Tue Aug 18, 2009 11:30 pm
by Major Redneck
That one does not look as bad as the red ones iv seen,,, more of the goth look... What about when it rains? Here in NC its kinda like "Riders of the Storm" in the summer months... My tech and I are looking into some foam to replace the stock paper filter... The tech's 110 has the red pod I did not like the pod filter looks... I really like the look of the stock airbox ...
Posted: Wed Aug 19, 2009 1:27 am
by B02S4
Here's my airbox cover, let's see yours...
The opening is oval, approx. 40mm x 35mm.
Posted: Wed Aug 19, 2009 2:11 am
by Major Redneck
All of the part where the big hole is,,, is cut out,,, filed down... Just take a 3/8" drill bit and go alone the side of that part,,, razer knife the rest and file smooth if you want... at this time i have no picture my cam did not enjoy the ride in the cooterhull and is getting looked at (i dont do camars)... With all that is cut out I think water well get into my airbox in a downpoor or suck in the mist from behind a truck,,, both which I do not intend on doing...
I must say the filter you have looks better than the red one... Have you done any looking into a larger intake and carb for the 110 or the big bore kit? Most my time has been spent with vaperlock,,, roller/clutch problems it seems... When the little 106 just starts to lug out (6 to 8000 more miles i hope) ill go with the bigbore i think 123cc and pipe as well as carb and intake bearings crank... First i want to replace the CVT parts,,, tires I need tires... Would be nice if a larger tire was able to fit the rear... The 10" is at its max. size... Any hint of a 12" rim anywhere??? Its just been too hot to ride anything the past few days here,,, I took the zuma out this morning to the Dr. and it does well but does not have the funness the 2T has,,, got the zuma up to 70mph downhill full out... Its fuel injeted... 4T parts 3X's what normal is for other bikes,,, and is so quite next to the Rattler I can not hear it run (few starter ups when its running)... Doc seen the helment tapped it with his pen and shook his head NO!!! BLood presser is normal... I am going to die just not today... My neighbor well let me use his cam tomorrow ill snap a shot...
Posted: Wed Aug 19, 2009 2:53 am
by B02S4
My modded airbox inlet is plenty large enough for the OEM carb & paper filter.
I am checking into a big bore kit & larger carb now. When that happens I'll also port the reed cage.
Posted: Wed Aug 19, 2009 3:55 pm
by Major Redneck
my cutout

Posted: Fri Aug 21, 2009 4:37 pm
by Liquidkool
MajorRedneck that looks like you grabbed a beaver by the hind legs and let him go to town to cut that out You should touch it up with a dremal and the drum sander bit
Posted: Fri Aug 21, 2009 5:35 pm
by Major Redneck
im handycap... was in a hurry,,, can always do as you said... more than enough air gets to that paper filter... it's not seen by normal human eyes... yea it kinda looks crude but it works wonderful...
With the 110 jet and that little ugly lookin airboxmod,,, im very happy with the power my Rattler has...
Once we find some foam to replace the stock paper filter ill then polish up the inside of the airbox... I want to cut out where the stock filter is making it a little larger and adding a foam filter...
Posted: Sun Aug 23, 2009 8:22 pm
by Liquidkool
yea i know it never get seen until you post a pic on the internet, i was just busting you balls a little i apoligize for that. in my opinion i hate the look of the stock box and whos gonna go out in the rain with a scooter. the uni filter is a clean looking, true performance upgrade
Posted: Mon Aug 24, 2009 1:39 am
by nissanman
You can't always plan to avoid rain

Posted: Wed Aug 26, 2009 7:47 pm
by Liquidkool
Low pro air filter from DDM modified from my go-ped, 115 main jet installed and YSS suspension from scooterworks, listed for yamaha jog. Yes its fully adjustable and a direct bolt on even with the stock airbox. I like to ride low so its all the up at the current moment.
Posted: Wed Aug 26, 2009 7:59 pm
by Ray Knobs
flowmaster eh?
How do you like the shock?
You setup looks great
Posted: Wed Aug 26, 2009 8:18 pm
by Liquidkool
Ha ha you like that just an extra sticker i had left over from my exhaust on my 97 Ram. You've got a keen eye.
I love the shock and its cool trying different setups, real easy to adjust it also comes with two span wrenches
Posted: Sun Sep 13, 2009 11:43 pm
by laxer
I finally got the Unifilter pod and the 115 about a month ago, but now my mid seems slow, anybody have any suggestions, maybe lowering the weight of the rollers a little? Thanks.
Posted: Mon Sep 14, 2009 6:34 am
by Keys
I installed a Uni-Filter. A single density job and have had my best results (at 3500 ft. elevation) with a 110 jet. Tried bigger and it bogs on the top end after I run with the throttle wide open for a minute or so. Back to the 110 and I was fine.
--Keys
Posted: Mon Sep 14, 2009 12:08 pm
by B02S4
laxer wrote:I finally got the Unifilter pod and the 115 about a month ago, but now my mid seems slow, anybody have any suggestions, maybe lowering the weight of the rollers a little? Thanks.
This has nothing to do with a modified airbox.
If you are at 4500 feet then why did you use a 115, when a 110 was already recommended?
Posted: Mon Sep 14, 2009 8:13 pm
by Liquidkool
I have 9 gram dr pully sliders in my stock variator and the acceleration is quite quick up to 55 then it jogs up to the top end, which is right around 63-64 indicated of course. With the stock pipe its a little slower off the line but it has more top end the the prima. I have also tried the multivar by mallossi with the rollers and contra spring that came with it and it takes quite a high rpm to get the clutch to grab but once it does HOLD ON cause i almost lost it. So after that its never gone back in, i think next i might try just the spring with my setup now, which is the stock pipe, 110 main, high flow air filter and 9 gram sliders.
Remember keep what works for you, not others

Posted: Tue Sep 15, 2009 3:43 am
by laxer
Sorry, seemed like others were talking about the unifilter on the thread and I didn't want to start a new one. My local scooter shop told me a long time back that they had ordered the jets, took forever, finally the 115 came in but they said that the 110 was on backorder. I was just seeing if others had had this problem. I guess I'll just mess with the mix screw on the carb and wait for the 110 to come in. Thanks for the help!
Posted: Mon Apr 05, 2010 7:22 pm
by Major Redneck
after many months of looking for just the right foam filter here is my stock airfliter mod... rubberbands keep it from sucking in the filter till i find some meshwire that well work for me... had to rejet the carb. to 1.2mm jet...
not only do i have great airflow i also have a wet foam airfilter to help trap even more dirt and this time of year POLLEN!!!
question??? do you that the the aftermarket UNI and other brands of "foam" filter,,, do you keep it wet with oil??? and if not why not??? was it not recomended ???
wet foam filter will trap alot more dirt and not hinder your airflow... in my view that is...
Posted: Mon Apr 05, 2010 9:35 pm
by Scalpel
Major Redneck wrote:question??? do you that the the aftermarket UNI and other brands of "foam" filter,,, do you keep it wet with oil???
I picked up some foam air filter spray and give it a good shot around the outside every once in a while. It does seem to help.
Posted: Tue Apr 06, 2010 2:58 am
by B02S4
Uni foam bike filters are designed to be run with Uni oil, not dry.
Posted: Sat May 01, 2010 6:37 am
by PGOPMX74820
ive lost m cover for my air filter, bike was sitting for a while. will the uni filter make the scooter as quiet with the original air box cover on?
Posted: Sat May 01, 2010 11:22 am
by bigbropgo
I will be louder with the uni filter. Someone with the modification done might be willing to sell you the cover. Or you might try to contact scooterworks.
Welcome to modern buddy. Hope you can find what your looking for.
Posted: Sat May 01, 2010 2:07 pm
by guam_rattler
Liquidkool wrote:
YSS suspension from scooterworks, listed for yamaha jog
just wondering what size shock is that....and what front shocks are you using to lower the front to match the rear?
Posted: Sat May 01, 2010 4:47 pm
by PGOPMX74820
Posted: Mon May 03, 2010 3:17 am
by Scalpel
Any of the Unifilter-style filters are going to be really loud. It's the trade-off for the extra oomph from having more air getting to the engine.
Air box Mod
Posted: Fri Mar 04, 2011 1:34 am
by Smiley13
Where did you get the foam to do this project. Wanting to make one too.
Thank you Smiley
Posted: Fri Mar 04, 2011 11:11 pm
by Major Redneck
the foam i used came out of a box that was shipped to me... little stuff like that is hard to hang onto till needed but priceless when needed...