This carb swap is NOT my idea or "find" its totally someone else's & this is just how its worked out for me. Your results may vary! got this idea from a local kids post online. He has a Mini & like most old Mini's he had this same carb problem. He swapped his out with a Rhino 660 carb. The reasons he used this carb are: 1. its CHEAP! brand new it was only $39 w/free shipping! 2. its simple with ZERO vacuum lines or extra goodies on it 3. it fits the space perfectly! 4. it works perfect off of the fuel pump already in use on carbed minis! 5. its readily available & so are rebuild kits. so lets get to it! first thing was to get the old carb unhooked, off & the coolant lines that went to it looped together. next was to get rid of the zillion Vac lines that go to the carb from all over & then to make sure that all the needed Vac lines were still hooked up from the tree. my Mini had a 3+2 carb from the factory on the Vac line set up. Good news is you can do away with many of these if you follow the handy diagram from the other carb thread thats posted. with that stuff out of the way you next need to get the air cleaner unmounted & so on. having a good view in your mind of how this is gonna look when done always helps on a project. i knew that i wanted this to look fairly neat & not cobbled together. first thing you need for the install is an adapter from the Mini intake to the carb. This is NOT something that exists right off. since my best friend has one of those fancy new 3D printers.... i took the original gasket for that space & traced it out & then added the kneck it would need to match the carb neck. sent this to Pryotex & had him print me out the result which is a carb flange adapter that fits like a glove! (pryotex is going to offer these for sale to those who need one!) You connect this to the manifold with the 2 bolts & the flange side goes to the carb with a simple rubber boot that you can get anywhere. (size is 2") next you connect the fuel line & plug off the return fuel line. ive not had any issue with not having a return line & the truck has ran for several hours now at all different RPM's & loads.... if it becomes an issue of flooding or flow thru? i'll ad the return back in with a regulator set up. next step is to work on the throttle cable. for this particular carb the cable is on the right hand side, but the cable is plenty long enough & all you have to do is cut the end off to get it thru the housing & then crimp a new end on the cable & insert it into the holder. worked perfect! pedal feel is very nice. something i did notice is the throttle stop that is built into the carb & for that you then go adjust your pedal down at the floor so that when the throttle stop is hit in the carb.... it is also bottoming out the pedal. This will keep you from pulling the cable apart or putting extra stress on the set up. moving to the only thing left to do! AIR CLEANER SET UP! coming out of the carb to the air cleaner you need another rubber adapter. i chose a 2" 90* rubber boot after not liking the original straight set up. this lets me relocate the air cleaner back to the frame rail under the bed & allows much easier air cleaner access. i took a piece of 1" square tube & welded it to the frame & then bolted the air cleaner to that thru the factory mount holes. This works great & gives you a nice looking install. only thing left to do was fire it up & set the idle & so on.... This is where some of you will tell me this is wrong, but it is what it is. i dont have my choke cable yet so no choke & cold...... hit it with a dash of ether.... she fired right up & roared to life. idle was good but a little fast. made sure she was running on gas & not ether fumes & let it warm up. she hadnt been started in a couple weeks & was flooded out by the other carb several times before that, so letting it run for a few mins was a good thing. after letting her warm up i set the idle for where it "felt" good. to me on these mini's they are good at about 1200 rpm. thats a touch faster than factory but you have to remember we are now doing something different than all those factory idle uppers it came with. At that idle speed i can turn the heat/ac on with no problem & it doesnt kill it. same for adding in the lights, high fan position & then when the cooling fan kicks in ..... all of this happens & the carb is keeping right up with it in a much simpler set up. once shes warmed up? you can turn it off & restart without ever touching the gas. just turn the key & good to go. when its cold? still need to get the choke hooked up! Then i'll be able to make a final adjustment & see if this solves the cold start issues it always had. now heres the pictures of everything & a parts list: parts list Rhino 660 carb from Calltrec $39 2" boot $4 2" 90* boot $6 choke cable $7 PIX!!
If anyone is interested or needs more input? let me know. probably missed some stuff along the way... The adapter flange will be $29 w/priority mail shipping!
you should post this to the facebook mini truck group: https://www.facebook.com/groups/1491121737584558/ Lately it seems like there is much more activity than on here...When I put in my new engine I fought with vacuum lines and still fight with the step up actuators wanting to work only when they want. I live in Nebraska and on cold mornings (lately 15 degrees or so) it really wants to bog down or die when headlights and fan are on at a stoplight when the step-up actuator decides it doesn't want to work
How can you post to Facebook? All I see on there is a picture with a couple of words that aren’t helpful. And then it disappears after a couple days. It is where it should be and the Facebook folks should come here to learn things. Threads and info are at least searchable here, I have ZERO luck searching Faceslap.
Actually, adapters exist for a few $ I was going to do this with a Harley CV-40 but ended up selling the truck. I have the CV-40 and adapters though
had looked at the Harley carb & it was just too much money for experimenting. then there is that flooding out thing. thats a 1200cc rated carb on a 660cc engine. just seemed like too much carb. as to FB? eh.. we dont allow or use social media platforms in our family. the internet & regular forums are more than enough. i prefer the forum style & share my stuff here, just like everyone here has shared their knowledge with me.
I bought a carb for an 883, and then swapped in jets appropriate for a 660cc. Metering probably would have needed tweaked as well but not as far off as you might think Rhino carb looks like it works well, and it's still a CV type carb right?
heres my first update! YES its still a CV style carb & its actually a mikuni ... got the choke hooked up. (bought the factory cable which cost more than the carb) and heres what i know so far: GOOD: when this thing fires up it purrs like a kitten & runs really well with a noticeable improvement in throttle response & power. huge improvements in idle, off idle acceleration & over all everything. once i start it for the day? its good to go & fires right up without any problem. not so good: its still a horrible cold starter!! its still takes forever to get it to hit & start. it just cranks away with no hit until all of the sudden........... varoooooom!~ this is still better than the old carb which wouldnt start or run no matter what.
The likely reason that it's a horrible cold starter is, the original carb controls the ignition advance in a different way than what you have it hooked up, and your carb might not even produce the correct vac signal anywhere for it. Ford did something similar in the 60's with a carburator that had a spark control valve and a distributor that was matched to use it.. I would loosen the distributor, remove the vac, and rotate it while cranking to see if it kicks over quicker... If it does, your just not getting the right advance signal... In that case I would use a Jimny JA11V EFI distributor and something like a Megasquirt to control spark. Program in your advance curve, and then your pretty set for EFI as well. Add to that, the Jimny Distributor is electrically the same as Geo Metro
^^ Matt im not sure that is in my range of wrenchin..... but ive got a guy coming over next week that has done the valve checks on these before. he also mentioned the valve trains on these tightening up. we'll see.
Megasquirt to control ignition would be easy. It's just a cam signal that you can dial in the degrees of advance you want. The valves do tighten up
Matt, heard this valves tighten up thing from several people.... but tiny overhead engines are just not something ive ever messed with. an old V8 of any brand? no problem! good news is the 2002 (zuki) is now running like a top & man it has way more get up & go than my 95 model!
dale, i can still see the pix in this thread & click on them so maybe its a broser setting for you? Matt, so broke down & pulled the valve cover & checked the valves... yup they were all way tight. went thru just like the book said & reset them all. also now have the Yamaha choke & throttle cables hooked up. so everything works clean & smooth. bad news: after running great for a couple weeks.... now it wont start at all. will stick it in the garage in a week or 2 & see if its got fire & so on. good thing ive got the 02 up & running!
update from another carb thread here and Fred gave some great info! this is a C&P of my post from there about adding a regulator. think you guys are on to something... i had a left over adjustable regulator & stuck it on there tonite. set it at 2psi. turned the key on, checked for leaks & cranked her............................... FIRED RIGHT UP!! now ive got no clue if this is a perma fix or if it was my lucky day. my new throttle cable will be here tomorrow then i'll see if it works again & if it lasts!
got my new throttle cable installed. that did the trick as far as carb working & so on. idles fantastic now. starts really easy COLD! thats a change! not real sure if ive got it quite right on my timing or if maybe ive got too much vacumn on my vac advance? every now & then i'll get a backfire thru the intake or it will stumble then catch up. good news is im getting really close! so positive thoughts are going on.
Good luck. I have quite a few old automotive repair manuals, from the pre-1970s, when cars still had carbs, and points. They have trouble shooting guides, which can be of a great help in working on my tiny truck. You can find the Chilton’s and Motor’s manuals from the sixties and seventies, pretty inexpensively on eBay. I also find them in thrift stores occasionally, and can get them for a buck or less.
The choke on these types of carbs is not really a choke. It is an enricher. Just allows extra fuel to bleed in. Some are electronic but I would want manual.. SU Carbs are another good option if you could fit one. A carb for a 1275 Midget/ Sprite or Mini would be 'right' ( those engines use 2 carburetors )
finally had it all worked out. timing set, idle set. starting good now & running much much better. though had already posted that in this thread, but must have been a different one.
The round with 3 screws looks just like the electric choke set up, is that the choke linkage? Matt do you still have the HD carb?
the round with the 3 screws is the throttle linkage. choke is on the opposite side. cable with the black connector. its a plunger style thing with a needle valve looking end on it instead of a flapper.
this is working really good.... when its sub zero out ? it still takes a wiff of ether to get her going... but the rest of the time ? pull the choke, crank till it fires & then let it warm up. got a friend here on this site & our gunboard who is working on EFI for his. will still go that route when he gets that finished. for now? this is good enough.
