I just hated the idle tube issues and constant aggravation. I understand that they worked for 30 years, but mine always had problems. Since my swap (only 3 months ago) I have driven my CJ every day but 3 and have not had to touch the carb for any reason. Also, I can now pass people on the highway and accelerate to to speed (probably not more than 80... haha) reasonably with stock gears and 33's.
Thise idle tube issues are a pain. I fixed mine 3 years ago, put some new filters in and no trouble since. Bagusjeep has only stopped twice from working in the last 3 years and that was for a dodgy electrical connection to a pump and a broken axle.
The BBD is characterised as being unreliable but I find it a reliable if unexciting piece of kit.
P.S. I pass people at all speeds, but no one drives that quickly here.
I have a base plate rebushed sitting on a shelf and a dead bbd in a box. When the throttle shaft guides wear to the point I can't compensate for it I'll put the other base plate on.
When the throttle shaft bushings wear out it messes up the idle and the fuel needle position will no longer match the butterfly position causing a hesitation. I just modify the slot so that the needles move as soon as the butterfly's start moving.
I like the BBD soo much I have done the nutter bypass with a twist. I paralleled the dizzy pickup with a MSD box. All the 'Puter Does is control fuel mixture. Timing control is know longer part it.
As a side note........the 258 has been known to have intake manifold gasket leaks. Which on turn cause some problems similar to a carb needing rebuilt. I wonder how many did carb swaps and still had carb problems when they were done? Or did a carb swap and redone the manifold gaskets at the same time when only gaskets would have fixed their carb problems.
BBDs might be fine after rebuilding, rebushing, etc. but point any of them up a steep hill and they will flood.
Then the float isn't set right. We climb sand pit and ravine walls until we are so steep the tires just churn in and none of the BBD's I helped folks tune ever stalled out on us. Check my sig line out for photos.
One trick about the float is you need two wrenches to put the gas line on or you will mess up the float level. One wrench has to hold the brass fitting at the carb or it will compress it's gasket which is the other side of the float setting.
86/00 CJ7 Laredo, 33x9.5 BFG AT's, 'glass nose to tail in '00, 'New' frame,wires and plumbing in '09. Carter BBD Carbed 4.0 HO in '10.
89 YJ Renegade. BBD Carbed 4.0 HO. Locked front and rear with 33x9.5 BFG AT's
Some Canadian Bush Jeep Runs and Build Photos: http://mikeromainjeeptrips.shutterfly.com (10 new albums added Sept 16/10)
If your BBD has the electronic "growth" sticking out the back of it go to the salvage yard and get a Dodge 318 truck BBd that does not have one. Have to go back in the 70's to get one before Holley repooped them. Use the Jeep base plate to keep your choke working. Install the upper assy to it. It will then be a much better carb. Play with the timing, advancing till spark knock sets in, back off till it is very faint or gone. Adjust the metering rods down till you get a stumble and move them up just a fine hair till it smooths out. Will run much better and increase mileage by 2-5 mpg. Have fun!
I rebuilt my BBD and had never taken apart a carb before. Like CSP says, the only problem I have is that it floods and stalls when you are in near vertical positions going up hill. Otherwise I have not had any more problems with the BBD and it even idles now 2 years after the rebuild.
have 2 of them one new got it from oreillys 216.00 have other one had it rebuilt put it in box coverd with plastic, sealed ytou can get really good at changing them out quick have friend that had weber took it off didnt like it he put ford carb on cj he likes it almost gets beter gas mileage then me
I too got really good at swapping out my BBD or taking it apart, cleaning the idle tubes, reassembling, and reinstalling. I have not gotten any practice doing any of that with my MC2100 (from '73 CJ5 w/304), as it has never faltered.
Increased dependability, increased power, better mileage (depending on driving habits) originally on a Jeep anyway.
USN Jeep Club Hull #135 (Retired USN 1992-2012)
'80 CJ7__258, TF999, D300__'86 CJ WT D44/D30's(3.54s)__GPF custom front/rear bumpers
4" springs__33x15s on black steelies__Galaxy DX959 CB__Cage (built onto YJ "family" bar)