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) Regulator install Dead headed and adjusted to 1.5 PSI 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 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. Mockup of the carb installed on the mount with the OEM air cleaner snorkel attached 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 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. 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. 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 Plug color at 4K rpm The exhaust setup
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.
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.
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!
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.
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.
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.
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.
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 $$$$.
Awesome write up, just did this to mine and learned a ton. If it weren't for that hanging idle issue this would be perfect, it runs really nicely otherwise. I took it out in the bush today though and it makes it impossible to navigate rough terrain when the idle goes up so high. I imagine this will be a nightmare once we get slippery icy roads, if I cant find a fix I may try a mikuni cv carb.
Yeah I could see it being a n issue in that case. Best bet is to get carb that has rotating assembly for the throttle cable (similar to the OEM setup). BTW, you will need to add a choke pull if its get cold where you are. I added one a while ago. Otherwise cold starts can be a harder. Nothing a good battery can't handle.
The hanging idle is a lean condition! try upping the pilot jet Oh wait you would need the Mikuni carb first
I adjusted the needle and jets back to what the carb came with. So the needle is at the middle position and the main jet is a 128 and the idle jet is a 32. Lean the idle out until I topped out the vacuum at ~18inHg. Cleaned out the exhaust and took in for 13km spin on my favorite test loop (half stop and go and the last half a highway sprint back). Ran great and could get up to 65+ mph on a level straight. Haven't had a chance to see what the mpg is yet. Need to fill the tank and take a longer trip. The exhaust wasn't as black as before so I know its leaner. The plugs were kind of dirty so at idle it was hard to get a good read on them. I still want to get a wideband.
Guys, the vacuum line that goes to the distributor (I think you called it a dizzy) does it have or need a Vacuum Check Valve/Vacuum Control Valve? The emission control diagrams show it as a Valve, Vacuum Transmitting. My Suzuki Carry currently does not have one and I wanted to know if one is needed while I do my motorcycle carb swap-out.
Great write up thank you for your efforts this will help many and seems easier than EFI to play with etc. I like analog mech more than ecus and software.
btw did you get the proper idle jet? would lower revving engines like these need to go smaller eg. 30 or 28 or go the other way to 34 or 36 slow jet?
OMG these are NOT lower reving motor! Mine will turn almost 8000 RPM! They are called Pilot jets and No it is a mater of How much air it will move!
So true! I don't have a tach but I wind mine out until it stops producing an increase in power on every shift. It screams with that turbo exhaust on it. I'm pretty sure a clutch job is waiting for me now, probably do the rear CV joints as well when that happens.
I added an extra spring to the throttle slide and that pretty much cures the hanging idle. I also just filled up with gas and already saw my mileage go from ~20 mpg to almost 24mpg and that was with part of the mileage not using the extra spring to fix the hanging idle. I suspect it will be a bit higher at next fillup.
Ok, finally got a real around town mileage number. I just top off and I'm getting 27 mpg which is a huge difference from ~17-20 mpg I was seeing after the initial swap. I'll be taking a long trip this coming week to the Kei truck on the dragon rally so I should be able to compile highway numbers easily. https://www.facebook.com/events/627776647038279/
Hey speaking of clutch, one thing I did (35,000k ago) Was I had the flywheel surfaced, then took off .020 more of the pressure plate surface This gave me more preload, works great Well now that I replaced the cable LOL
Did a long trip with multiple fillups and saw consistent mpg no matter whether I was cruising or running hot in the mountains. It's basically 28 mpg all the time now.
