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Suzuki Every carb swap

Discussion in 'Suzuki Carry' started by t_g_farrell, Feb 15, 2024.

  1. t_g_farrell

    t_g_farrell Active Member

    I had some issues with my Every van and after rebuilding the OEM carb, it wouldn't hold idle when it came off the choke. Ran fine with the choke but the idle circuit was plugged somewhere. I tried to fix it a couple of times but to no avail. Thats when I saw @Bigsullie000 posting up about his Nibbi carburetor conversion on his Carry. This is similar to doing a Rhino carb install but its just a better carb than what you get off Amazon from China and they have a USA location for support etc.

    What you will need with links for purchases:

    Drill bits needed
    11/32 used to drill carb flange
    15/64 used to drill carb top for throttle cable

    JBWeld used to anchor new stop on throttle cable https://www.oreillyauto.com/detail/...ounce-epoxy/jbw0/8281?pos=4&manufacturer=true

    Nibbi Carb https://www.amazon.com/dp/B076CHWY6X?psc=1&ref=ppx_yo2ov_dt_b_product_details

    Jets https://www.amazon.com/dp/B096RY9T8Z?psc=1&ref=ppx_yo2ov_dt_b_product_details

    Carb mount https://www.amazon.com/dp/B0B6FNQF31?psc=1&ref=ppx_yo2ov_dt_b_product_details

    Flange bolts for carb mount https://www.oreillyauto.com/detail/...anged-bolt/dor0/980420d?q=m8-1.25+bolt&pos=11

    Vacuum line https://www.summitracing.com/parts/TBS-TS-HV0303-BE

    3/16 fuel line https://www.oreillyauto.com/detail/c/masterpro-hose-clamps/masterpro-3-16-inch-x-2-foot-fuel-hose/mhc1/fu0316?q=3/16+fuel+hose&pos=1

    Fuel pump https://www.pegasusautoracing.com/productdetails.asp?RecID=82

    Fuel Pressure Regulator and plumbing
    Regulator - https://www.summitracing.com/parts/SUM-G3033B
    Hose barbs - https://www.summitracing.com/parts/EDD-844640
    Plug - https://www.summitracing.com/parts/SUM-921022-2

    Choke remote cable bits

    Choke cable - https://www.amazon.com/gp/product/B0CJ4JS79D/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

    Choke cable fitting for carb conversion to cable pull - https://www.amazon.com/dp/B00J4Z9S7S?psc=1&ref=ppx_yo2ov_dt_b_product_details

    Extra bits and pieces for cable work - https://www.amazon.com/dp/B00BLGKQE...UF7PDP7R&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

    Great write up on tuning a PWK carb like this https://static1.squarespace.com/sta...4730/1542561947962/KeihinCarbJetting-2015.pdf

    For this project I chose the Nibbi PWK32 mainly because the inlet and outlets are exactly the same outside diameter as the OEM carb. It also spaces out well so the OEM air box snorkel can still be used. I also went with a 32 carb because I think it will be more than adequete when tuned to fuel this motor.

    My fuel supply setup now uses a Facet cube 1.5 - 4 psi pump that is dead headed at the inlet to the carb. Plugged the return line and removed the fuel reserver container and hoses as well. I have used these pumps on similar other Japanese carb setups that are picky about the pressure (for example the Nikki carb on my 1980 RX-7). I have a regulator that is adjusted down to 1.5 - 2 lbs. Without it the idle circuit was overwhelmed and very rich. Impossible to tune without it.

    Fuel pump install
    keep original connector, cut off at old pump
    wire hot black/white lead to red on pump
    wire pump ground to chassis (its better than going thru the harness, mesaured with DVM to verify)

    fuel_pump.jpg

    Regulator install
    Dead headed and adjusted to 1.5 PSI

    regulator_install.jpg

    Removed the old carb and the water and vacuum lines
    remove carb with all the lines attached

    plug the 5 water outlets

    keep dizzy vacuum line and line to the air box to control hot air

    oem_carb_vac_removed.jpg

    oem_carb_pulled.jpg

    Making the carb mount work
    Drill out each hole using the 11/32 bit
    Notch the short side to it is centered on the opening. Use the OEM spacer to verify this.

    carb_mount_modified.jpg

    Mockup of the carb installed on the mount with the OEM air cleaner snorkel attached

    nibbi_mocked_up.jpg

    Modify the throttle cable for the Nibbi
    Cut the end off at ~42mm when stretch tight from the end of the throttle cable end. You may want to leave a couple of mm extra.
    Get a red wire crimp on, push the metal center out and cut off piece that maybe .25in in length
    crimp_joint_cablend.jpg

    Push this over on to the cable so that 1/8in of the cable shows out of this metal stop cylinder. Flare the cable a bit on the end and separate the strands on the very end a bit to the JBWeld can get in there and bind up good.
    Push the stop up the cable. Use some JBWeld to paint the last 1/2in of the
    cable then push the stop down so that some of the cable barely protrudes
    from the stop. Wipe off excess (don't wait). Let set overnight.

    Modify the Nibbi for the Suzuki throttle cable. The cable will not screw into the top of the carb as is, its slight larger than the threading on the top of the flange.
    Remove the top
    Remove the ferrule on the top
    Drill out just the threads so the throttle end can fit thru it using the 15/64 bit

    Attach throttle cable to the carb
    Pain in the a$$, be careful not to loose any parts if it pops apart while trying to get it all together.

    nibbi_installed.jpg

    Dealing with the vacuum lines
    Vacuum for the airbox stays connected to nipple on intake
    Dizzy vacuum goes to the nipple near cylinder 1 on the intake
    Dizzy probably wants ported vacuum (meaning no vacuum at idle but gets vacuum at throttle open) but the carb doesn't have that on it. So timing needs to be done with the vacuum disconnected for the dizzy.

    nibbi_install_final.jpg

    final_install.jpg

    Initial carb setup
    45 slow jet
    145 main jet
    Needle clip down on notch from what it was as delivered (2nd notch)
    Air mix screw 1 1/2 turns out
    Speed fill screw 1 turn out
    Idle screw all the way out, so idle is not adjusted yet.

    Tuning notes
    Reduced slow jet to 32 air mix stays the same
    Idle adjusted to 900-1000 rpm with no vacuum advanced. Vac
    advanced hooked up brings the idle up to about 1300 rpm

    Will post next about hooking up the choke cable to replace the manual choke on the carb.

    The carb in conjunction with the new exhaust and the cleaned out catalytic converter runs well and is about as loud as touring motorcycle (like a Honda 750). Right now tune is almost ideal for idle and a bit rich for mid throttle. WOT throttle hasn't been verified yet but would appear to be just a bit leaner than mid range.

    Plug color at idle

    idel_plug_color.jpg
    Plug color at 4K rpm

    mid_throttle_plug_color.jpg
    The exhaust setup
    exhaust_install.jpg

    new_exhaust.jpg
     
    Last edited: Feb 27, 2024
    Liberty4Ever likes this.
  2. t_g_farrell

    t_g_farrell Active Member

    Some notes on the swap. It runs great with the exception of two things:

    1. The throttle doesn't go back to low idle sometimes and I have to blip the pedal to settle it down. Seems these carbs exhibit this behavior with 4 stroke engines due to the high vacuum they generate at idle.
    2. The manual choke is not usable when I button up the van because its under a cover on the floor at the rear of the van. For a truck theres an easy fix, get Harley Davidison remote choke cable and replace the manual choke and run the knob thru the floor to the cab somewhere. Its a bigger challenge with the van. Details in a later post on what I did.

    I have yet to run it on some longer trips to see what the mileage is like but its not a big issue to me I'm just curious ab0ut it.
     
  3. t_g_farrell

    t_g_farrell Active Member

    Took it out to C&C here in Charlotte which was about 50 minutes each way. Ran really well, I think its a bit rich on the main jet and/or needle but otherwise really runs a lot better.
     
  4. KCCats

    KCCats Active Member

    The one thing I can tell you in compared to what I did
    I mounted the OEM air cleaner to the engine NOT the frame
    And always use Real Mikuni flange!
     
  5. t_g_farrell

    t_g_farrell Active Member

    I wanted to reuse the OEM air box and boot with no changes. The front carb flange is an exact match in diameter for the OEM front flange so the rubber boot for the air box bolts up with no issues. I had a couple of choices for the intake flange and chose the one that I could center the hole on the intake and the carb so there would be no squirrelly air flows happening. So far its working good. I just took the main down from 145 to 140 to lean out the off idle some. I may take the needle back up one notch as well. I'll run it for a bit to make sure the mixt feels right first. I should get a wideband but thats $$$ I'm not sure I want to spend.
     
  6. Bowe

    Bowe Member

    I ended up at 142 for my main, puts it ~12.5:1 at WOT and full operating temp. This is on my Minicab with cv40.
     
  7. t_g_farrell

    t_g_farrell Active Member

    Good to know. I wonder for these 4 valve 3 cylinder Suzuki engines what the best AFR to run is?
     
  8. Bowe

    Bowe Member

    I can’t say for sure but I’m erring on the side of slightly rich, want to be safe when I’m really wringing in it out.
    How is the throttle response with that carb? I imagine it has off idle snap that the cv carbs are lacking.
     
    t_g_farrell likes this.
  9. t_g_farrell

    t_g_farrell Active Member

    Its really good, it pulls strong off idle. Revs out really well. Top speed isn't much different but you get there faster. Heres an example. I have a matchbox minitruck in the cubby below the radio. Before when I was driving it would roll left and right as I made turns but never fell out. Now when I take off it flys out of the cubby hole, so I have to be careful when accelerating.
     
  10. t_g_farrell

    t_g_farrell Active Member

    I am rich at the moment as well just to be safe. Will gradually lean it up as I get time with it. Toying with getting an wideband but so much $$$$.
     

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