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92 Mitsubishi U42T Carb Swap

Discussion in 'Mitsubishi Minicab' started by Henry C Gonzalez, Dec 11, 2021.

  1. Henry C Gonzalez

    Henry C Gonzalez New Member

    I just destroyed the plastic curved jet holder inside the carb float bowl. Thinking of doing a carb swap with a 1904 Holly side draft single barrel, used in 60s era Ford 6cyl engines. Mounting holes are very close to the Mitsi but the throat is aprox .25 larger. Seems like a very simple carb to use and INEXPENSIVE. I know that there is a butt load of vacuum & water lines to plug or re-route. Advise or thoughts?
     
  2. fmartin_gila

    fmartin_gila Well-Known Member

    The 60s six cyl Fords were 215, 223 & 240 CI which is quit a bit more than the 40 or so CI which we have in the Kie vehicles. You may find that you can't cut down the fuel flow enough to run properly. As I remember, the 1904 Holly needed 4 to 7 lbs fuel pressure so you may need a new electric pump to push that much pressure. Use your head dealing with the water & vacuum lines and you could come out a big winner. Would be a very interesting swap if you can do it, let us know your progress.

    Fred
     
    Last edited: Dec 11, 2021
  3. Henry C Gonzalez

    Henry C Gonzalez New Member

    Thanks for the info. Too much fuel flow is something I had not thought of. I was leaning towards this carb but not 100% sold on it yet; still looking for other options.
     
  4. fmartin_gila

    fmartin_gila Well-Known Member

    There has been quite a bit of discussion about carb swaps in the past in the Suzuki posts. Do some reading there as there is a lot of info to be gained in the thread as to what has been tried and what some results have been.

    Fred
     
  5. Henry C Gonzalez

    Henry C Gonzalez New Member

    After some research I made the plunge and purchased a CV-40 carb. They are used on some Harleys 880 & 1200s. Good or bad decision, we shall see. I'll will have to make my own carb to engine mount for the engine side but the carb will mount with a rubber throat & clamp. And so the adventure begins. I will update progress.
     
  6. VanOne

    VanOne Member

    Just a heads up, there is an adapter kit available: https://www.ebay.com/itm/303809955022?hash=item46bc7c04ce:g:y3AAAOSwq1tflzpZ (includes
    On my 1987 U15T with the 550cc engine it runs a bit lean(absolutely no power on 4th gear) with the default settings, but the carb certainly handles the engine.

    [edit]I do advise installing a EZ mixture screw if yours doesn't have one, cause the screw is going to be at the bottom of the car so if you want to adjust the mixture it'll be bit of a headache getting a screwdriver in due to all the hoses right around where the mixture screw is if you leave the default screw in. I had to use a clock repair screwdriver due to how small the mixture screw hole is, not to mention how small the space is you are going to be working in. Do install it before putting the carb on the car, and do it so the screw is facing up so you don't let the other components fall down when you remove the mixture screw to install the EZ one.

    Mine had the mixture screwed in all the way to lean by default apparently, took quite a few turns before I got it where it would accelerate properly, and idle without stalling on me if lights and blower were on.

    Mine is missing the enricher components inside the carb, there was just a screw on the enrichment port.
     
    Last edited: Dec 18, 2021
  7. Henry C Gonzalez

    Henry C Gonzalez New Member

    Thanks for the info. I just ordered the adapter kit. Anything to make the conversion less painful. Will use your advise when I start the install. Will also provide feedback on the site incase others are thinking of the same conversion.
     
  8. VanOne

    VanOne Member

    And if you are looking for a place to run the choke/enrichener cable, at least on my U15T there is an unused slot for wire/hose near the firewall on the drivers side slightly left of the clutch, just before where the center console/heater is bolted on to the wall. I assume this was meant for AC hose or cables for dump switch since my truck has neither.
     
  9. Henry C Gonzalez

    Henry C Gonzalez New Member

    Carb swap is complete and it runs and holds an idle. Problem; the carb bogs down like it isn't getting enough gas. I'll have to keep playing with the adjustment till I find the sweet spot. Worst case, I might need another jet as I live at 6600 feet in elevation. The swap was simple with very little fabrication. I used the adapter kit mentioned above and a quick adjust screw. Conversion was as follows: 1. Layout the adopter kit and make sure it fits into the carb intake and engine side. 2. Mount adopter to engine and mount rubber intake tube to adopter. 3. Mount the carb for a dry fit to check clearances. 4. I removed the double throttle cable holder from the carb. 5. I cut off the return cable holder and bent the remaining holder to the angle that the throttle cable would be run from, welded where I cut and remounted to the carb. 6. Mount the carb and attached the throttle cable, choke cable, fuel line, and vacuum line. 6. Cut the fuel line and attached an inline filter and fuel cutoff valve. 7. I removed the stock air filter and attached a HD filter. (bolted right up to the carb). 8. I attached an additional support mount to the front of the carb for additional support to keep the carb from vibrating off. 9. plug off any open fuel return lines and vacuum lines (still working on this one). Carb 2.jpg Carb 2.jpg Carb 4.jpg Carb 5.jpg Carb6.jpg Carb8.jpg Carb10.jpg Carb 1.jpg
     
  10. VanOne

    VanOne Member

    Yeah your problem sounds very similar to mine. Unfortunately the weather here hasn't allowed to me to properly get under the truck to do the pilot jet swap to see if that fixes my issue, cause I could go all the way rich on the mixture screw, it wouldn't stall but neither did I have any power on any gears at that point. I've gotten it to where I have full power on 1st, pretty much full power on 2nd, 3rd is somewhere around 75%-80% depending terrain, and 4th(which is overdrive) is just completely useless anywhere but completely flat or downhill. Starts right up when warm with my current mixture, cold start takes several attempts.
     
  11. Henry C Gonzalez

    Henry C Gonzalez New Member

    Well I'm at my wits end with this one. As stated above it starts up and idles great. However it keeps bogging down and when it is not good and warmed up, I can't get enough power to get the wheels moving. I've tried various jets in the carb but no joy. Any ideas out there? This is my work horse on the ranch and use it also to clear snow; missing it big time. Another carb perhaps? I'm reading a couple of posts on the Suzuki side on Mikuni 40mm carbs for Suzuki DR650 motorcycles? There is also a post on UTube for a successful Suzuki Carry conversion to a carb from a Yamaha Grizzly 660 UTV. Got a couple of things that I still want to try before I give up totally on this carb. If successful I'll post it.
     
    Last edited: Feb 22, 2022
  12. Henry C Gonzalez

    Henry C Gonzalez New Member

    So I gave up on the CV-40 carb. As stated above, I could not get enough power out of it to move the mini. I purchased a carb from ebay for a 2006 Yamaha 660 Grizzly. It clamped right up to the adapter kit that I had installed for the CV-40 carb. My accelerator cable went right on without any further mods and the same for the choke cable. I then purchased a reusable air filter from ebay and installed a hose from the top of the carb to the air filter. I drilled out the fuel air mixture screw cap incase I had to play with the mixture later. It came stock with the screw closed all the way. I also installed a fuel pressure regulator and set it for 2 psi. This was an easy install. It starts right up and idles great. I still have a slight bogging down problem but not like before. I would say I have 80% improvement. So I have my workhorse back. Hopefully with a little tweeking of the carb adjustment and fuel pressure I can get it to 100%. All in all I am pleased with this carb swap. Yamaha Carb on Mini 1.jpg
     
    fmartin_gila likes this.
  13. Henry C Gonzalez

    Henry C Gonzalez New Member

    Update on 660 Grizzly Carb: I have been driving it on the rancho about a month now. I have not tried to adjust the fuel flow or change any jets. It is running fine. I still have a little bogging down prob when the engine is cold but not anything like before. I think it was a good swap for me. On a side note, my muffler died. I changed it to a Thrush turbo and also took off the catalytic converter. Seems like I have a little more power.
     
  14. Basscor

    Basscor New Member

    I am in the middle of doing a conversion to a 660 grizzly carb as well. What did you end up doing with all of your vacuum lines? Specifically where are you pulling off for the vacuum advance for the distributor?
    Thanks!
     
  15. Henry C Gonzalez

    Henry C Gonzalez New Member

    I disconnected all the vacuum lines from the plastic tree that comes from the manifold. I then plugged up everything and capped off the vacuum nipples on the tree. I think there were 3 nipples. My distributor was never connected to the vacuum. However, I took the distributor line and connected it to one of the nipples on the tree. The only thing that has a vacuum now is the distributor.
     
    Darlene and fmartin_gila like this.
  16. mark gerdes

    mark gerdes New Member

    do you guys have your original mikuni carb? i have the cushman u42 4x4. with the 4g82 mitsubishi . im trying to make it run right with the original carb. bought the carb kit from china. runs pretty good but not perfect. wont idle. thought i might try to find a core since they are not available.
    i opened up the transmission and did away with the govenor . when it runs right its a rocket ship.
     
  17. Basscor

    Basscor New Member

    I do have mine, but I'm not sure it would work with the 4g82 engine. I am still working on getting it to run properly on the grizzly carb, but if/once I do I shouldn't need my old one anymore.
     
  18. mark gerdes

    mark gerdes New Member

    thanks for the reply. i worked on mine some more today, got it to idle better, but i dont know what i did. idle circuit is a mystery. in the bowl there is a check ball and a rod in the side with a tiny retaining clip. i think it has something to do with it. the clip was gone, had to make one.
    i would like to keep mine original if possible. mega zip shows that the 3g and 4g had the same carb. the year may be an issue. i think mine is an 98-99 model , right before they went efi.
     
  19. Henry C Gonzalez

    Henry C Gonzalez New Member

    I do have my org Mikuni carb. the curved plastic jet holder inside the fuel bowel is broken but all else is there. I was going to put it on ebay but now days you have to give them too much information to sell something. Mini Carb6.jpg
     
  20. mark gerdes

    mark gerdes New Member

  21. VanOne

    VanOne Member

    Well, my CV40 saga on my 3G81 equipped U15T continues. I finally picked up the courage to take the carb off from the intake, and engine so I could turn it to remove the bottom plate so I could access the idle jet. Jesus on a bike, the float was full to the brim even though the truck had been sitting for 4 days. I noticed the float pin just comes right off on its own, I don't think it is supposed to do that. Was tapping on the carb lightly to remove the idle jet I had unscrewed and the float tried to make a run for it....

    Just as everyone knowledgeable in the Harley scene has said about these Chinese knockoffs, the idle jet is a #45 and main jet is #175. The idle jet is definitely too large, I downsized to #40, yet to see the results cause I'm having issues with getting the intake boot back on...it just is a too damn tight fit. Put the carb end on, and try to put the carb on the engine and the damn intake keeps tearing it off, try vice versa and the damned intake hose won't go on either end.

    I also noticed the carb side of the intake boot had a tear on it, I put some insulation tape on it as a quick fix while I figure what I do..probably get a free flowing filter cause the stock air box + intake boot turns you nuts every time no matter what you are doing, but then there is the issue where the engine breather hose etc all go. New intake boot is 70 euros with shipping...if it actually exists.

    [edit]Yeah, threw away the stock intake/airbox, I couldn't get it back on. Definite improvement on gas pedal response, no more weird ass whine when you downshift. Choke still doesn't work, could be a shoddy job on my part with the cable end. I retained the little round thingy that sits on the airbox duct just after the front air duct, EGR is plugged into that at least. It has no connection to the air ducts besides a line going to the air filter box, so I'll get that end hooked up to the new free flow air filter.
     
    Last edited: Jun 26, 2022

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