135$ Brand new IDF 40 Weber knockofs on ebay

[Piledriver]

If I could do singles or duals for the ~same price as you can, I would personally not even consider a single setup for a heartbeat.

Its a well known and extensively discussed issue... Its also why that manifold exists...
It is the best possible setup if you must run that setup.

When Webers cost $400 each new, a single sorta makes sense.

The only advantage a single setup has is linkage simplicity and carb access, on a Baja runner that only runs in the heat and usually at WOT it works.

Running duals almost requires (for your sanity) cutting an access window in the inner fenders (with covers)...
simple holes with pop-in covers work. They actually sell pre-fab access windows these days.

A cable pull linkage ~eliminates the "simple linkage" and carb balance advantage of a single.

Of course for the last few years I have only viewed Webers as a possible lower cost ITB for EFI anyway.

[Marc]

The only reason I'm running a single carb is that I can't fit any duals known to man until I cut my frame apart and reroute the upper tubes (this is a midengine setup, and the sandrail exhaust has no provision for a heat riser). I'm down on the flatlands near Seattle where the climate's much milder...sub-freezing temps are a rarity but it's often cool and damp.

Years ago I had a Baja with a 300CFM Holley Bug Spray 2-bbl. It had preheat but still had problems with carb icing - some days it would be so bad that I'd conk out on the freeway - I carried a propane torch (and fire extinguisher ) so I could thaw it out. It had a steel independent runner manifold which I jacketed with welded-on sheetmetal panels, with the center of the heatriser pipe cut out. This formed a cavity similar to that of the "deluxe" IDF manifold which was sufficient to solve the icing problem, but it still required rich jetting for off-idle throttle response. For winter I cobbled up a coffee-can based cover for the aircleaner, connected with a 2" hose to a metal scoop to pick up warmed air off one of the heads - that helped a little.

The single center-mounted IDF is popular for sandrails and offroad buggies competing in classes which allow them, but those are typically run in warm weather and mostly at WOT - it's just not a good setup for year-around street use outside of places with a warm climate.

If you plumb your heatriser pipe as described and use the deluxe manifold, you might be able to make this work well enough to live with in a light vehicle where the flat spot won't matter so much. I don't have much experience at high altitude but theoretically the ideal jetting would be leaner than down here, you might start with the 200 airs and see if they'll work with just bigger mains....~150 for starters?

Good luck.

[GoMopar440]

One of the biggest reasons I'm sticking with the single IDF right now is I can only afford one carb at the moment. If I could have afforded to buy a second carb right now, it would have already been on the way in the mail with this first one. I still need to set back another $190 for the manifold before I can even put the single IDF carb on the rail.

If this clone carb works out to be OK, I'll most likely pick up another one just like it later on. After I do a bit more work on the engine, I'll revisit the dual carb idea again. But for now, I'm just going to run it with the single center mount carb for a while and get that working as well as I can. It's still a little too early for me to be asking jetting questions yet, but I hope to get it running on baseline settings and start tuning it by this Spring.

[Piledriver]

You can get the second carb, 2 decent dryflow filters, and bits for a nice DIY cable linkage for =/< the cost of that manifold and do it in smaller bites.
Just sayin...

Good luck in any case.

[FJCamper]

Hi GoMoPar;

The reason almost no one with experience recommends a single Weber is because what they have either done first hand or seen first hand to try and get a single to run right.

VW hot rodders have been willing to try anything, and sometimes it's paid off. But the single Weber never has.

I got humbled by one back in the day after opening my mouth and telling a single-Weber Bug owner that I was good with Weber's. I was too, but just with the 48 IDA's on our road racing IMSA Super Beetle. Of course, I then had the guy calling me and coming to my house for weeks so I could make it run right. Being stubborn, I fought that SOB until I had fully come to doubt that I knew anything about Weber's in particular and carburetors in general.

I wish you luck. Hope springs eternal.

FJC

[GoMopar440]

Having a fixed/limited budget as a primary factor restricting the speed and scope of my rail project really sucks. I hope I don't sound like I'm blowing off all these excellent suggestions in my responses. I'm really not. I have to let the limited budget make a lot of decisions for me that I would prefer to do differently if I had more money to do so. Running a single IDF style carb will get me by for a while, even if it's not the optimal setup. It's bound to be better than a single center mounted PICT at least. At worst, it'll suck as a single setup and I'll have to pony up and get another IDF carb and a pair of dual manifolds for them. Wait... scratch that. At WORST, the chinese IDF clone could be a total turd and I'd have to invest in a set of know quality carbs to fix it. The EMPI gen 3 HPMX's have been getting very good reviews pretty much everywhere I've looked, so I'd probably go that route if I have to use different carbs other than these clones. If I look at it like that, if I'll risk loosing less money by trying out just one clone carb VS buying two unknown quality carbs right out of the gate.

Last night I ordered a Weber tuning book on Amazon, so that should help with tuning when I get to that point.

[Piledriver]

Everyone lives there, I'd just like to encourage you not to throw good money after bad.

$50 for a set of manifolds used (or less) and another carb, and you could install and test the carbs and return them if they turn out to be turds.
They are probably jetted about right.

You can rig up a functional linkage in a couple hours, or borrow one if needed.
You might even be able to borrow some manifolds.

Right now you are apparently planning on spending as much or more, $200(shipped) on a manifold, PLUS trying to jet the single right, and the end result is pretty well determined by physics.

[GoMopar440]

Then I'm back to buying a second carb of unknown quality and an iffy return policy to deal with in the event of untunable carbs. I'd feel better about going with a second carb and some used intakes and linkage for them with a little reassurance that these carbs will work out ok. Has the OP ever replied back with how the carbs he got a re working yet? In the last post I saw him make, he mentioned what jetting came in them and also that they looked ok on the outside IIRC.

[Piledriver]

I have yet to get stiffed on ebay, and I have gotten one refund direct from ebay/paypal as the seller was entirely bogus, within 72 hours of filing a report..
The linked seller has reasonable feedback, and isn't a newbie AFAICT.

You need to see if it works, the sellers return policy is moot if you sit on it for 6 months.

Good luck on whatever you decide.

[GoMopar440]

I'll have to make up my mind fairly quickly which way to go with this because of the fact I already bought one and the return clock is ticking. I'll take the sellers review history into account, but I've had issues with Ebay's buyer protection policy in the past. The policy may be better these days, but that past burn still stings when I think about it.

Eh, I guess if I'm still that wary of it, I probably shouldn't have been shopping around on Ebay after all. It's my own damn fault if I get burned again I guess. Hopefully the carb will look great straight out of the box, the jetting will magically be spot on for my engine, altitude and air density, and a miniature flying unicorn will jump out of the box burping up pixie dust and farting rainbows as it flys around the room.









It's past my bed time and I probably shouldn't be posting right now...
Catch you guys in a few days when I get back in town.

[FJCamper]

Hi Mopar,

I highly recommend dual Solex 40/44 EIS, popularly known as the Kadron. With the right throttle bodies, venturis, and jets, Kad run a close second to Weber 44's in performance.

The reliability factor of the Kads exceeds the Weber's, as Weber's are highly prone to idle jet clogging and dirt contamination in general.

We run Kads in Lemons endurance racing in a Superbug. Here's a video.

https://www.youtube.com/watch?v=zvYgzPgBRaw

Towards the middle to the end of the video, watch us take down the BWW's.

FJC

[GoMopar440]

I was able to get online using my dad's Wifi router so I'll be able to check in at night when I'm not as busy.

After mulling over the carb options during the 13 hour road trip I said F-it and went ahead and got a second IDF. I figured I'd come here and let you guys know that you convinced me to stop being such a tight wad for once. I went back to the same seller and got one more of the 40 IDF clones from the same (updated) auction. The only difference is now the price is about $12 higher than the first one I bought.

Now I see that I'm being told to go buy different carbs altogether... Where's that "banging my head against a brick wall" smiley when I need it? Sorry FJ, but I'm gonna have to leave the Kads for another day and another engine. I'm already invested way too deep into these IDF's now to do anything else.

Oh yea, I got to thinking about that return clock ticking away. I really need to get the IDF's on an engine and tested out quickly in case any issues pop up. In order to do that I'll need all that other stuff to make it work. I was looking at this kit from CB (#3125) since I've heard that they make the best linkage from more than a few people. When I started pricing all the pieces separately the kit comes out cheaper if I get it all in one shot. http://www.cbperformance.com/ProductDet ... 5&CartID=1 With the cheapest shipping option available it's $214.48. Thinking. Thinking. Thinking.

These "cheap" carbs are turning out to be a lot more expensive that I had imagined.

[Piledriver]

Good.
The air cleaners are OK, but dryflows (or whatever K&N calls them) are MUCH better filters, the gauze filters pass rocks.
The rubber seals also don't, the castings are too rough.
K&N sells basically urethane bushing grease in a tube, goop in on the rubber bits, helps a LOT.
So does RTVing the filters to the air cleaner.
They are just as easy to clean that way, and they don't shrink so bad with age.

But...
Unless CB has completely redesigned their hexbar (spits) I'm fuzzy if those people with the pretty linkages actually drive their cars.

I was impressed when I installed the hexbar, looks cool, very heavy duty everything, but that's its main fatal flaw.
It didn't last a month before I got fed up, and in a beer fueled rage, with a drill, a sawzall, and a cat I replaced it with stuff I had laying around..

I do ~500 miles a week commuting.
Engine vibration, combined with the mass of the hexbar and other bits causes the accel jets to dribble constantly.
It can also be impossible to get the geometry 100% right, and sync changes from hot to cold.
The lack of real bearings on the shaft is the least of its issues...

The first cobbled together bellcrank setup I made via Home Depot that the hexbar replaced worked better.

If I can find the bits I'll mail it to you if you really want it, but I don't feel it a favor.
(The bar would probably be too short though, cut down for a T4)

You can make a better linkage from the Weber bits and a dead bicycle if you have any fabrication skill at all.
No welder or anything weird...
If you have a motorcycle salvage nearby its a piece of cake, and maybe $20.

Search for cable pull linkage.
The pulleys are entirely optional, but are easier in some ways, and totally linear.

[GoMopar440]

I may just start with getting a pair of non-offset manifolds and look at what I need for a linkage when it gets here. I don't want to wait too long to test it out though since the return window may close if I delay getting it up and running.

[GoMopar440]

It may have issues as noted, but I decided to give that CB kit I posted a shot for now. I offered less than the lowest price I could find with shipping and the Ebay seller accepted.

I figure it will be easier to modify it to suit to my liking if I at least have a starting point to work with for now. Both carbs and the kit should arrive sometime next week. I'll get started on getting the engine in the rail tuned up and fixing a few leaks on it while I'm waiting for the carbs and other parts to arrive.