Engine dies

I have a lawnflite 404 ride on mower with a briggs and stratton 6.5 bhp vertical motor. This afternoon after a couple of fills of gas it started running rough and would only run well with the choke half out.
I thought it must be a blocked jet in the carb as the machine had been working ok up to then.
i finished the lawn with the choke half out and then returned to the garage and stripped the carb. I was surprised to fined there is no apparent with needle valve in this carb or adjustment screws for mixture. It is of very simple construction with simply a ventury pipe into the air flow.
I blew it through with compressed air and reassembled it. It is now worse. It starts and dies immmediately. Any clues guys that might help. Thanks.

Compressed air most likely blew the main jet out of the cab.
Or jambed what was originally partially blocking the cab so far in and so hard it is now fully blocking carb and unable to be removed.

We need the engine numbers Mdel, code *& serial to be able to hepl you any more.

bertsmobile1 said:

Compressed air most likely blew the main jet out of the cab.
Or jambed what was originally partially blocking the cab so far in and so hard it is now fully blocking carb and unable to be removed.

We need the engine numbers Mdel, code *& serial to be able to hepl you any more.

Click to expand...

I believe the model and serial no are on a metal plate. Sadly this is missing. I could not find any other markings on the engine. I am assuming it is a 6.5 hp as that is common on these mowers.
There is no idle screw as I think this engine is designed to run at constant speed, only a small red lever to reduce engine speed via the govenor linkage when not cutting. Also there is no mixture adjustment either. Does this help. Comparing images online it would appear to be an Intek 60. engine.

here are some pictures o

t There does not seem to be a needle jet at all unless it went ping as I removed the bowl and did not see it. It has the number 214661 cast on the side of it

If it has a bowl (and it looks like it does), it has a float. If it has a float, it has a needle valve to maintain the level of fuel in the bowl. If it is a non-adjustable, single speed carburetor (and you said it is), it relies on the diameter of drilled passages to control the fuel/air mixture. Those passages have to be clean for the carburetor to work right.

The bad news is these carburetors clog up easily. The good news is these carburetors don't cost much to either fix or replace.

The only Briggs carburetor I've seen without a needle valve are those that bolt to the top of the fuel tank and draw their fuel directly from the tank via a 'stinger' that protrudes into the tank itself, thus using it as a 'bowl.'