My 3W 60 engine which I am running in all of a sudden is not drawing fuel. I think it is the carb. My first 3 tanks were ok. Than I did not start it for a couple of weeks. What can I do to the carb.

Check the screen first.

I have the 3W-60 rear careb which would run fine once started but would not draw fuel to start. I would have to remove the spark plug and prime it to get it started. I bought the motor here on RCU and it looked like it was only run once or twice.

I found out that the reed valves were frayed. If you have the rear carb check the reed valves.

tonyc

If I manually add fuel through the ventura and flick the prop a few time it will run for 2 or 3 seconds and die. It is obvious the fuel is not being drawn by the carb. I am not sure whether to open the carb. I am not sure whether I can put it back to gether.

It sounds like the carb has some dirt in it. The only way to know is to look inside. If you do not feel like you can do this then I would take it to a local small motor shop. The carb on this motor has been around for a very long time and the local small motor shop in your area will be able to help you. Its a quick fix to get the dirt out. Requires no new parts. If you do need a carb rebuild kit, you can get that at the same shop. Here I just bought one and it cost $8.50. This has more parts then you would need but you can rebuild the whole carb with this.

good luck

If there is an air leak between the carb and the engine, the vacuum pulse port will leak and the carb will not draw fuel. The pump side of the carb may have dried out too. Remove the gas line off the carb nipple and squirt WD-40 in the hole in the nipple. Put the gas line on and see if it will draw fuel. If your fuel line is loose anywhere from the carb nipple to the tank, it can leak air and not draw fuel.

A piston port engine will always have a pulse...A reed valve engine will have a pulse as long as the reeds seal completely..Frayed reeds can't seal enough to make a good pulse like a piston port engine....[
3w engines use a neoprene plate for the carbon fiber reeds to seal against, and the plate also has to seal all the way around the outside where it fits into the crankcase...
The air from the piston coming down forces the reeds against the plate, forcing air through the pulse hole to the carb...When the reeds are frayed the piston just pushes the air back out the carb....No pulse, no pump...Turning the engine with a starter makes more pressure than hand flipping, so it works better....

My 3W 50 will not draw enough fuel to hand flip start. I had a damaged reed valve and replaced it. I have to use a starter to get it going. After it starts, it runs great. I have looked at everything and it appears to be leak free. Guess I will just keep starting it with the starter. If anyone has an idea, let me know. John