DBAK with a Twist

By Tony Anzalone - GoldKnight67 (on the V-Star Forum)

2002V-Star 1100 Custom

I finally did the DBAK, (Dad's Big Air Kit), individual Filter Pod System. I have been using the Hy-Flow Air Mod for about a year now and my bike runs real strong.

But now it is time to take it to the next level, remove that restictive Snorkle plumbing, the factory Air Box and yes do all that tearing apart & jet testing. ugggg!

This mod was originally developed by "Dave Benson" as the JAK, then called the DBAK and can now be purchased in kit form at Maxair. The Maxair DMAX kit $219.00, is complete with K&N Filters, Adapters, Multible sets of jets, Drill bits, tools, etc. All you need to do the job including "Great Tech Support". Dave .... Thanks for developing this... YOU ARE THE MAN!

You can find other articles on DBAK at George Dumpit's site or on the Star forum Starchives JAK Article #1 & Article #2.

The Twist?: I used the UNI "PK-92" oiled Foam Racing Filters in place of the K&N oiled Cloth Filters "RU-0981", (much less than half the costs of the K&N, for a 2 filters set is just $34.00 + Oil). And are better according to testing performed by AMSOIL. Amsoil Test

Parts Needed:  ............... (OEM Stock V-Star 1100 has 17.5 pilot jets, a 110 and a 112.5 Main jets)

2- UNI Foam Filters PN# PK-92  UNI Filter Web Site

2- Mukini 147.5 Main Jets  PN# KN102.221-147.5 (or 2-145 Main Jets PN# KN102.221-145 or 2-142.5 Main Jets PN# KN102.221-142.5 or 2-140 Main Jets PN# KN102.221-140)

2- Mukini 22.5 Pilot Jets  PN# KVM28/486-22.5 (or 2- 20 Pilot Jets)

8- Hex Head metric 4mm-7 X 10mm  ........ (to replace the phillips head screws on the float bowls)

8- Lock Washers 4mm ........ (float bowls)

8- #4's washers aprox .020 in. shims for the needles. I got them at Lowes, 4mm washers.  The wahser were a little rough so I ran some sand paper over them to get rid of the burrs.  You can also get some #4's washers at Radio Shack, Steel Washers mixed sizes 20ea. in a 100 pack, PN# 64-3022a.

1- 2" ID diameter (2&1/8" OD) X 4" lenght of exhaust pipe.

1- 1&1/2" Fernco Plumbing Adapter,

1- Spraycan of UNI Filter Oil

Total cost of materals for DBAK  $61.00

I removed the stock Air Filter, Snorkle Plumbing, Air Box under the tank and after removing the carbs, I used "Long Nosed Vice Grips" to break the original philips head screws on the float bowls.  

I now replaced the Main Jet, (thats the one with the needle sliding into it and is marked 110 or 112.5), and the Pilot Jet, (That is the long skinny jet).

PMS: (pilot mixture screw), is set aprox 2&1/2 to 3&1/4 turns out from full in,.(start at 3). Now, you can adjust the PMS while it is idling with a 90 degree driver as seen below  that I purchased  from JC Whiney.

click on picture for larger image


Brass Plug: If this is your 1st time adjusting your PMS, you will have to remove the factory brass plug hiding the screw. Slowly and carefully drill a 1/8th hole in the plug , (don't drill too deep or you will hit the PMS screw behind the plug). Insert a PK screw and pull out the plug.

Adapter:  (This is the same adapter setup used by Dave Benson when he developed the DBAK, now Maxair).

The Filter pods require a 2&1/8" fitting to be attached to, thus the pipe 2"ID 2&1/8"OD. The Elbow to the carbs need a 2&1/2-5/8". Use a 1/2" rubber slice from the 1&1/2" Fernco rubber pipe adapter. It will snugly fits over the pipe and fits into the elbow.

Cut the Fernco into (2) 1/2 inch slices from the thick center section, (this  fits in to Elbows,) ....... Now cut the pipe into (2) 1 inch slices, (this fits in to the Pod filters and the Fernco).

click on picture for larger image


Crankcase Breather: I had previously installed a simple aftermarket Breather that I now just re-located under the tank.  You can read about it at the end of the article - Hy-Flow

Settings may Vary from one Bike to Another, so get a few different Main Jet ranges for dialing it in!

Reported Initial Start Settings with K&N Filters at Sea level

Exhaust  System Type

PMS Screw

Pilot Jet

Main Jet

Factory Needle Hight

Stock Factory Pipes




F = 1 shim .020 set by Factory

Drilled Factory Mufflers




(F + 1) .020in /.508mm (add 1 washers to factory)

Baffled Slip On After Market

2.5 - 3



(F + 1) .020in /.508mm (add 1 washers to factory)

Full System After Market

3 - 3.5



(F + 1) .020in / .508mm (add 1 washers to factory)

Reported Final UNI Filter Settings  (So far the UNI's appear to need one Main Jet size Larger than the K&N's)  

Exhaust Type




Needle Hight


Biker Name


HK 3.5" Slip-On's w/baffles




(F + 3) .060in /1.524mm

Sea Level


Bubs Big Willeys Full w/Baffles

2.5 F&R.



(F + 1) .020in / .508mm

750 ASL


Perfect Tan

HK 2.75 Big Straights Full w/Baffles




(F + 2) .040in / 1.061mm

Sea Level


HK 2.75 Big Straights Full  

**Straight Pipes w/ adjustable Baffles

1.75 22.5 147.5 (F + 3) .060in / 1.524mm Sea Level GoldKnight67 Light/Tan
Stock Modified Factory Pipes 2.5 22.5 142.5 (F + 1) .020in / .508mm Sea Level Roger Tan

If you do this UNI Filter mod please Share: E-mail me with your settings and I will post them, Thanks

Testing & Tuning:

Relax and have fun as this will take a bit of time to fine tune it in. For the most part if you started at 2 to 3 turns out on the PMS and the correct # of shim washer on the Needles it should run pretty well. Actually you should adjust the PMS & Synchronize your carbs next, but most people are in such a big hurry to test it out, they do it later.

After my 1st Initial Testing and Tuning.....  I went for a test spin and I was nicely surprised as I power shifted 1st to 2nd gear at 6200rpm and felt the back wheel break loose.  WOW!  It never did that before! Now I will do some Cruise & WOT, (wide open throttle), testing to dial it in. 

The basic concept is to find a nice section of open and lightly travled road to test on. (if possible).

Main Jets: WOT: Run at full throttle fourth gear for as long as you dare, cut the engine, pull in the clutch and coast to a safe area. Pull the plugs after it cools down. Plug color will tell if the Main is correct.

Needles: Cruise range: Run for a mile or so at about 3500rpm to 4000rpm in third gear, (or 62mph in 5th), cut the engine; pull in the clutch and coast to a safe area. Pull the plugs after it cools down. Plug color will tell if the Needle height is set correct. So add or remove a washer as needed. Be careful with the vacuum cover there is a spring under it and 1 tiny "o"ring.

Tech Tip: Make sure you have 1 small factory washer on the top of the needle, (the wide end), under the spring & retainer . 

**If you add more than 2 washer to the factory washer & needle you will have to file about .040in. off the back end of the needle so that the spring & retainer will seat fully, on assembly.  But if you need more than 3 washers you may need a larger main jet?

I know I can be a bit anal about perfection. .... lol!  But if your close to set up but the next washer is too rich and it runs a bit lean at your current setting? I hand ground another set of  .020in shims down on a hand sharping stone to the .015in. I am fine tuning in small increments, because I rather be a bit rich with a air cooled engine.

PMS: Idle for a couple of minutes and pull the plugs after it cools down.

Plug Color:  White = too lean. Black or Sooty = too rich. Tan to brown = perfect.


Dail-A-Jet.  DAJ range of adjustment is diminished as less vacuum pressure is created by a wide open air kit like the DBAK or Maxair because of the removal of the airbox.

Test & Settings at Sea Level with "UNI Filter" on HK 2.75 Big Straights
Settings PMS Screw Pilot Jet Main Jet Needle Hight Comments
Installation Initial Setings 3 22.5 145 (F + 1) .020in / .508mm (add 1 washers to factory) Very Lean Mid & Top
Tuned to Settings After 1st Run 2.5 22.5 145 (F + 2) .040in / 1.061mm (add 2 washers to factory) Lean Mid & Top
Tuned to Settings After 2nd Run 2. 22.5 145 (F + 3) .060in / 1.524mm (add 3 washers to factory) Bit Lean Mid & Top
Tuned to Settings After 3rd Run   HK Big Straights Full w/Baffles 1.75 22.5 147.5 (F + 1) .020in / .508mm (add 1 washers to factory) Hint of Tan Mid Tan Top
Tuned to Settings After 4th Run / Final   HK 2.75 Big Straights Full w/Baffles 1.75 22.5 147.5 (F + 2) .040in / 1.061mm (add 2 washers to factory) Tan
HK 2.75 Big Straights Full

**Straight Pipes w/adjustable Baffles

1.75 22.5 147.5 (F + 3) .060in / 1.524mm Light/Tan

***Notice              It has been reported on the V-Star Form that "Winter Gasoline", in the months of Oct through March, has Oxygenators in it, such as Ethyl Alcohol or MBTE, which adds oxygen to the combustion equation and makes the engine run leaner. So your choices are:

1) Tune on the rich side in general, 2) raise the needles in the winter

**Dont Forget about syncing the carbs - Carb Sync

Make a Functional Air-Scoop as a option of what to do with that big open area where the Air Cleaner was?

Have Fun & Ride Safe

Tony Anzalone

Give the Glory to GOD

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