WUR Adventures

ducatiroger · 08:59 PM

Hello All,

Been enjoying my 76 911s w/3.0SC engine. It's been running well in most cases and joy to drive. There is/was one condition where if I gave it full throttle the car would seem to run lean once I backed off with a slight backfire on the exhaust side of the engine. If I came to a stop or pushed in the clutch the car would not idle and die. If I let is sit for 5-10 seconds and then restart the car it would run normally and idle just fine. A couple of months ago I had disassembled the WUR in an effort to understand why the car was running poorly and found what looked like a clogged (partially) inlet mesh on the WUR:

A bit of brake clean and some compressed air had the screen looking much better so I reassembled the WUR. As mentioned the car was running great and it seemed like the full throttle/lean condition was improved. Fast forward to earlier this week and I ran into the full throttle/lean condition issue again and resolved to have another looks at the screen. I purchased an ultrasonic cleaner anticipating removing the screen from the WUR and giving it a good soak. Well that operation did not go according to plan. I'd read you should be able to push out the screen(from the inside) so I inserted a 1.5mm allen and gave it a push only to find the screen still resting in the WUR but now with a 1.5mm hole. Doh!

At that point I gave up and reassembled the WUR (with the damaged screen still in place) hoping to enlist the Pelican brain trust on how to proceed. I seem to remember some folks running the WUR without a screen which is what I'm doing in principal now, but prefer to have some sort of filter for the long run. Prior searches for replacement screens/mesh didn't yield any results. I haven't done a full throttle pull with the "modified" screen to see if the lean condition is resolved yet. Maybe tomorrow.

Does anyone have a lead on where to source a WUR mesh screen, or am I best off finding a used WUR with a better screen? Maybe installing an external filter pre WUR? Any suggestions would be appreciated.

Cordially,

Roger

RarlyL8 · RarlyL8's Garage

It is not unreasonable to assume your entire fuel system is in the same shape as that original screen. Running without a screen is not going to end well. I would flush the entire system and empty and clean the fuel tank. Your fuel distributor is cast iron and rusting from within, only a matter of time before it begins to malfunction. EtOH blended fuels accelerate this action as does allowing the car to sit unused for extended periods.

ducatiroger · 11:19 AM

Quote:

Originally Posted by RarlyL8

It is not unreasonable to assume your entire fuel system is in the same shape as that original screen. Running without a screen is not going to end well. I would flush the entire system and empty and clean the fuel tank. Your fuel distributor is cast iron and rusting from within, only a matter of time before it begins to malfunction. EtOH blended fuels accelerate this action as does allowing the car to sit unused for extended periods.

Thanks for the feedback. I have cleaned the tank and tank filter. Most of the other fuel system components have been cleaned except the fuel distributor. The first WUR photo was from a few months ago. The car has been running well with the one exception noted in the previous post and has been driven regularly since in my care.

Sure would like to track down a replacement mesh filter for the WUR.

Update: Found mesh filters available at K Jet Specialists in AUS.

Cordially,

Roger

range83 · 09-10-2025, 12:16 PM

Quote:

Originally Posted by ducatiroger

Thanks for the feedback. I have cleaned the tank and tank filter. Most of the other fuel system components have been cleaned except the fuel distributor. The first WUR photo was from a few months ago. The car has been running well with the one exception noted in the previous post and has been driven regularly since in my care.

Sure would like to track down a replacement mesh filter for the WUR.

Update: Found mesh filters available at K Jet Specialists in AUS.

Cordially,

Roger

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