1600 engine 009 dizzy pancake filter weber carb. Van was backfiring so I took carb off and fitted new needle valve as this fixed the problem a couple of years ago. When I bult it back up aand started it up it idles fine for about five seconds then slows down and splutters to a stop.It seems to run fine when I have my foot slightly on the accelerator keeping it at 1000 revs. Any ideas what it could be and how I can fix this?
What have you done thus far? Have you checked the basic stuff like valve clearance and timing first? Is it a stock 1600? They usually run best with the stock gear, i.e. solex carb and oil bath air filter.
With a 009 I’d run it a tad richer . And up your idle revs a tad , it will help flat spot if you don’t want to spend money on different set up .
Vacuum hoses all tight? Had my engine out at the weekend and the brake boost hose was loose when I put it back together, had similar symptoms.
I would say your needle valve is the problem, or your float height, I find the repro valves to be pretty poor generally
Should be a screw somewhere. If not you can change the needle /jet size. I have to rebuild chainsaws all year long. 90% of the time it’s the carburetor.. taking it apart and putting it back together it does wonders.Even if you don’t change anything.. Drive a while and check the spark plugs color. It also gives you a good chance to check your gaskets to the intake manifold. For leaks. Or bad vacuum.
so would that be the float too low?how do I adjust that is it just a case of bending the arm slightly?
Personally, I’d get rid of the single Weber carb. You’ll spend the rest of your life trying to get it running properly. Go for twin carbs, or back to a Solex. And get rid of the 009!
So does mine. Open up the hot run throttle endstop, the one on the side, a smidge to give a bit more idle speed then tweak the mixture screw for best lean idle. And you should have it tweaked round the back so it sits on the choke stepped cam round the back when its cold to hold the cold idle higher. Mine backfires popping and crackling on high RPM throttle closed e.g. engine braking in third. as the mixture is good on the gas I dont care. Chuck the 009 aand connect up an SVDA , refit a stock air cleaner and hot air feed.. then there is nothing wrong with a Weber progressive, and then you can lean out the jetting and it still doesnt hesitate
Screw on throttle lever on side of carb, front spindle. It moves with the spindle. The idle adjustment is round the back, another screw on an arm resting on a stepped cam linked by the wire on the left .. (Edit with correct labels on picture)
