On Jun 2, 2009, at 7:01 AM, "John" <downing.j@sbcglobal.net> wrote:
Lynn, do you happen to have the dimensions for the float level in the Weber 48. I have the Haynes manual on Webers, but I can't find the float level for the 48. The engine won't start with the carb unless I inject some WD-40 into the carb, the idle adjustment is set according to spec's. The larger return line lowered the fuel press to 0, so I set it at 3 pounds, which fills the carb with gas without leaking. JohnD
Here is the picture from page 10 of the Racing Beat catalogue, and I see it came to them from BAP/ Geon, who no doubt got it from a Weber catalogue.
The float level has little to do with hard starting. Does it start and run OK after you spray in the WD-40?
Does it only run as long as the WD-40 is being sprayed in?
Does it have good compression?
A clean fresh Weber is bullet proof. They generally come stock with 36MM chokes. And the jetting will be correct for that choke size. Choke=main venturi size. The chokes are removeable and available in various sizes. Even the idle circuit is adjustable. However, the extremes in idle jetting are just about not detectable, and can be modified with the idle air screws.
Rotaries are cold blooded. An old piston engine term to describe a hard to start engine. All carbed engines are hard to start in cold weather, because the fuel will not atomize, and is difficult to light, and is likely to wet a spark plug and not start at all. The rotary carries this into warmer weather by have a huge amount of cold surface area in the combustion chamber, and, high compression leak rates due to dozens of seal gaps.
Properly assembled, and with a fully charged battery, and a fresh crisp starter, it will start and run either instantly with a conventionally triggered ignition system, or after one full revolution with the stock reluctor wheel triggering a stock or similar electronic ignition system.
I used to start engines with WD-40 on very cold days, or if the engine was sealing poorly from wear. Or for a really bad one, motor oil followed by gasoline from a oil squirt can. Big smoke cloud, but it runs fine. A warmed up engine will then start because the heat will vaporize the fuel.
Check that battery voltage is not going below 9.5 volts while cranking. Otherwise you need more plate area, or a better starter. Just back up the battery with a jump battery or from a running car.
If the engine is ported with a later closing intake, it will be harder to start. (lower compression)
If the side seals are started out with more than .002" it will be hard to start.
If its a junk high mileage engine it will be hard to start.
If it is a fresh engine with new seals, it should be easy to start after three hours of running.
Lynn E. Hanover
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