Weber Carburetor Adjustment
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dchsw
Weber Carburetor Adjustment
Anyone know an online guide to adjusting Weber carbs? Or give me some insight as to where to start? The 2.0 engine in my '55 86" is (I think) running rich. Idles ok, but coughs and splutters like crazy when you open the throttle. Once open, she'll rev quite well but then dies away and there's no real power. Anyone running a weber on a series truck care to share some experience? Thanks, David.
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Roverworks
Hi
As you are no doubt aware, carbs are “jetted” with small orifices which meter fuel at the approximate rate of requirement for various throttle openings/vacuum. The “jets” can be varied (by exchange) but the butterfly (which varies vacuum) can not. Perhaps the carb is jetted for 2.25L? Mechanical accelerator pumps are variable for fuel delivery volume as well. Engines of different design OHV or side vale, long stroke or short stroke have different requirements at different moments during acceleration.
However, before you consider the carb go back and check your compressions and engine vacuum. A vacuum gauge is an inexpensive and valuable diagnostic tool. You will often find the installation of a manifold fitting to allow the connection of a vacuum gage on old cars (done by wise old mechanics). The gauge when read properly will indicate many conditions from late valve timing to late ignition timing as well as bad rings and valves etc. Remember the carb is a vacuum dependant instrument…no vacuum…. no work.
I have seen the Weber mounted on the 2.0L side valve but have never thought they run quite as-well as the correct Solex when in good condition. Perhaps I have never seen a Weber on a 2L that was properly jetted.
Carburetor means “don’t touch” in French ;-). It is much less frequently the problem than most believe.
Alan Simpson
Rover works B.C. Ltd
As you are no doubt aware, carbs are “jetted” with small orifices which meter fuel at the approximate rate of requirement for various throttle openings/vacuum. The “jets” can be varied (by exchange) but the butterfly (which varies vacuum) can not. Perhaps the carb is jetted for 2.25L? Mechanical accelerator pumps are variable for fuel delivery volume as well. Engines of different design OHV or side vale, long stroke or short stroke have different requirements at different moments during acceleration.
However, before you consider the carb go back and check your compressions and engine vacuum. A vacuum gauge is an inexpensive and valuable diagnostic tool. You will often find the installation of a manifold fitting to allow the connection of a vacuum gage on old cars (done by wise old mechanics). The gauge when read properly will indicate many conditions from late valve timing to late ignition timing as well as bad rings and valves etc. Remember the carb is a vacuum dependant instrument…no vacuum…. no work.
I have seen the Weber mounted on the 2.0L side valve but have never thought they run quite as-well as the correct Solex when in good condition. Perhaps I have never seen a Weber on a 2L that was properly jetted.
Carburetor means “don’t touch” in French ;-). It is much less frequently the problem than most believe.
Alan Simpson
Rover works B.C. Ltd
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Roverworks
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Greg S
- Spanner Man
- Posts: 844
- Joined: Sat Feb 28, 2004 9:00 pm
- Location: Duncan
- Contact:
There are only 2 adjustments, idle stop and low speed jet. Make sure all the orifices are clean.
When I was having troubles with mine, I went to the Weber site and downloaded the instruction sheet. It is a web copy of the sheet included in the box when you buy a new one.
I was plagued by a speck of dirt inside one of the jets.
When I was having troubles with mine, I went to the Weber site and downloaded the instruction sheet. It is a web copy of the sheet included in the box when you buy a new one.
I was plagued by a speck of dirt inside one of the jets.
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Greg S
- Spanner Man
- Posts: 844
- Joined: Sat Feb 28, 2004 9:00 pm
- Location: Duncan
- Contact:
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dchsw
Tanks for the info guys.
I'm on an enforced " No Land Rover Fettlin' " break for the next few weeks whilst I attend to more urgent matters, but after that I'll be back on the case.
One thing to mention - the truck in question is currently running on a gravity feed as the fuel pump sucked in some gunk from the rusty tank whilst with it's previous owner. Could it be that I'm actually getting too little fuel?
If I let the truck idle and use low range I can quite happily putter about the yard on tick-over so long as I don't touch the throttle.
Cheers, David
I'm on an enforced " No Land Rover Fettlin' " break for the next few weeks whilst I attend to more urgent matters, but after that I'll be back on the case.
One thing to mention - the truck in question is currently running on a gravity feed as the fuel pump sucked in some gunk from the rusty tank whilst with it's previous owner. Could it be that I'm actually getting too little fuel?
If I let the truck idle and use low range I can quite happily putter about the yard on tick-over so long as I don't touch the throttle.
Cheers, David
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Roverworks
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pleask
carb problem on series I
Hi David, could you please contact me off line if you still have your series I ?
I'm restoring up a '56 in Victoria and need a wee bit of help!
thanks, Pat
[email protected]
I'm restoring up a '56 in Victoria and need a wee bit of help!
thanks, Pat
[email protected]