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89 b2200 weber carb issues PLEASE HELP!

Old 05-20-2019, 04:25 PM
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Location: north carolina
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Default 89 b2200 weber carb issues PLEASE HELP!

I have a 1989 b2200 that i just had a mechanic put a weber carb on, it has a mind of its own, when it is at operating temperature it idles really high and when i go to turn it off it acts like it wants to turn off then at the last second it wants to run and kinda dies out on its own. I know these carbs are really particular and are hard to get dialed in, need any help i can get! i like the truck a lot but ive had it for 4+ months now and its only been on the street for about 2 weeks now and i just want to get it right.
Old 05-20-2019, 05:02 PM
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Take off the Weber and the adapters, and sand the mating surfaces PERFECTLY flat using wet/dry on a sheet of glass.
Making Weber adapters flat
Lay out a sheet of 80 grit emery paper on a piece of glass the workbench, taped all 4 sides of it down, and ran both sides of both adapter plates back and forth on the sand paper until they were actually FLAT. From Redline, they were not even close to flat, though they seemed like they were. After taking off all of the high spots on both, I installed them one final time - and never had another problem with them again. No more vacuum leaks. No more nuts that wanted to loosen up. No more tedious re-seal jobs.And use a thin film of Permatex Aviation (NOT RTV) on the gasket surfaces. Torque the bolts correctly.

Three things typically come to mind with a Weber 32/36 DGEV installation.
1. Was a thin coat of Permatex or similar used on all the gaskets for the adapters and bottom of carb? Were the mounting screws and bolts all torqued correctly? Did you use blue Loctite on their threads?

2. Did you plug the electric choke of the Weber into the rear of the alternator? If the bi-metallic spring doesn't get heat from the choke heater to open up the choke butterfly, the fuel:air mixture will be richer than it should be for a warm engine.

3. Are all the vacuum ports capped off with GOOD quality caps (or short pieces of vacuum tubing and golf tees) ?

Here are the notes I first made when I installed the genuine Weber 32/36 DGEV on my 1988 B2200 in early 2005; mine runs real well, by the way.
Weber carb installation tips genuine Weber K675 kit Weber hints Weber tips Weber installation

Important not to have vacuum leaks, should check/sand adapters for flatness, have learned that since I installed mine.

I installed mine about 6 years ago, and I've heard some of the issues I had with my installation have been addressed. Check the adapter surfaces for straightness, and "sand" straight using wet/dry paper on a sheet of glass, to help eliminate vacuum leaks. Instructions are included, use blue Loctite, correct torque, and also use gasket sealer. The electric choke plugs into the rear of the alternator like the stock one.

From then:

My comments about genuine Weber K675 kit for Mazda B2200 1988 (Weber 32/36 DGEV) from my own installation about 6 years ago; note that some of the issues may be corrected by now.

See instruction manual at

See exploded parts diagrams at or Weber 32/36 DGEV DGAV Diagram

Buy some extra 5/32 inch vacuum hose for stuff like the distributor vacuum advance, and some vacuum block-off caps (or use vacuum hose and golf tees). Some have suggested better quality vacuum caps can be obtained at .

Weber spring. Weber return spring. Weber throttle spring. Buy a new throttle return spring at the hardware or parts store; the one supplied is weak. Ace Hardware spring #22 seems like a good fit (2” long, 3/8” coil). The little plate with two holes in it is to mount on the engine for the throttle spring bottom attachment.

Instructions detailed a 6mm hex/allen key being required for the adapter screws; actually, it was a 5mm hex key required, and I cut down a 5mm L-shaped hex key with a hacksaw to use in my 5mm socket so I could use my torque wrench to get 12 ft-lb of torque like the instructions stated.

Bottom adapter plate needs to be ground away around the intake manifold PCV inlet, best if a bench grinder is available; there is a picture showing this, why couldn’t manufacturer just take care of this?

I replaced the brittle, hard PCV tubing with 3/8 inch fuel line.

The supplied carb mounting studs are too long (they are the same length as those removed from the intake manifold). A shorter one is needed for the rear right location to have clearance to get the nut on; I had to cut one shorter for that spot. I’d also advise installing the studs BEFORE mounting the top adapter, there’s no other way to make sure that they don’t get installed too deeply.

The top adapter plate could go in either of two orientations as it’s not symmetrical. I still don’t know which way is correct, not shown in instructions. There is apparently a right way and a wrong way to install the top adapter plate with the studs! If you hold it up to the bottom of the carburetor you will see that it is slightly wider on one side than the other --- the wider side (with the tab and the two notches) goes toward the valve cover - as the secondary (larger - "38") barrel is towards that side -from member from MazdaTrucking.

Note that my own adapter measures the same on both sides, and has the tab/notches also pointed towards the engine/valve cover.

I’d recommend using the 12mm head nuts from the Mazda to mount the carb itself, as the supplied ones have a 13mm head (the threads are the same). This will provide more clearance for tightening. These 12mm head nuts are available from Japanese vehicle parts counters or as JIS nuts at places like Ace Hardware. Better yet might be special ACN nuts: Special 8mm x 1.25mm flanged nuts that use a 3/8 inch socket

VW Parts Search Results - Aircooled.Net VW Parts Store

ACN Flanged Racing Intake and Exhaust Nut, 8 x 10mm, EACH - Aircooled.Net VW Parts

The instructions did not mention how to mount the return spring at the bottom; it turns out that there was an almost-oval bracket with two holes included for mounting in the place where the dashpot was, but no mention of the bracket was in the instructions. It's actually better to mount it on the rearmost EGR valve bolt.

One side of the two air cleaner clamps for the rear need to be ground down a little so that they seat fully into the bottom groove; if not, they will hit the carb itself.

There should have been a right-angle adapter for the crankcase ventilation hose; the supplied one points down, making it difficult to attach to the valve cover outlet because of the bends required. I used a brass right-angle 3/8 tubing fitting and 15/32 smog hose for this; I saw in a photo of a kit online where a right-angle adapter is shown. The hole in the air cleaner bottom was just a pinch too small for the supplied adapter anyway, so I had to ream the hole a little larger.

Instructions should’ve stated to re-route the choke wire more to the front of the engine so that no extension to the wire would be needed.

I added a L-shaped bracket to the supplied accelerator cable bracket for my add-on Audiovox cruise control. I ‘broadened” the cable groove using a small vise-grip as the cruise control cable was a little to the side. I used a 2 inch corner brace mounted to one of the now-unused valve cover holes to attach the accelerator and cruise control cables with a cable tie, to keep them off the hot valve cover.

I used three #2 rubber stoppers from Ace Hardware to seal off the reed valves; later I removed the whole assembly, made my own block off plate. I used 14mm x 1.5mm wheel lugs from O'Reillys ($4.99 for four) to plug the pair tube outlets coming out the upper manifold heat shield.

Instructions did not state whether I needed to put any oil like K&N on the new air cleaner element.

Instructions were not clear about the EGR valve connection. Apparently they meant that the vacuum hose that went to the thermo valve (underneath the manifold, has two vacuum ports at an angle) now goes to the EGR port on the carb. This is the port just rearward of where the distributor vacuum advance goes, but the small brass cap needs to be unscrewed first with a tiny screwdriver.

Photos are posted at

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