How does a carb primer bulb work

The problem is when it cuts out, it takes awhile before I can start it again.

How Does the Primer Bulb on a Walbro Carburetor Work?

If the engine has been run in the last 10 minutes or so and is hot, you don't need to turn the choke back on before re-starting. I doubt whether he ran the strimmer on pure diesel.

Don't use four-stroke motor oil in your engine. Any ideas why this could be occuring? I would have thought excess fuel would combust, so on second thoughts maybe as the exhaust gasses expand, the temperature drops to a degree that water vapour condenses out in the humid atmosphere. The Walbro carburetor primer bulb is a small plastic bulb which sits on the outermost casing of the carburetor.

how does a carb primer bulb work

When starting a trimmer, it can be reluctant to run without choke for the first 20 seconds or so until it warms up and get's going and the carburetor reservoir fills with fuel. Two stroke engines are easy to flood and you may have to leave the engine for 15 mins or so until fuel evaporates.

How the Primer Bulb Works on a Briggs & Stratton 5 Horse Engine

I often see just the plastic bulbs for sale online without the base that has the check valves. The problem rectifies on cooling. October 17, 2005, 08: Pulses of low and high pressure from the engine crankcase move this membrane backwards and forwards, and this sucks gas from the tank to a reservoir pocket in the carburetor.

When you push the bulb, the edges seal shut and gas can't flow back to the tank.

how does a carb primer bulb work

Hi Don, Thanks for your tutorial and all the info on 2 Cycles. John Albers has been a freelance writer since 2007. Unfortunately, spare parts are unlikely to be widely available for repairing such a model although the store may be able to get them from their supplier , which was probably mass produced in China. The centre of the diaphragm no longer pushes down on the lever and the needle valve starts to close, preventing further fuel from being pumped in.

If you find your trimmer leaks fuel when not in use, the problem can be caused by a damaged tip on the metering needle or an accumulation of gum.

how does a carb primer bulb work

To clean the valve, gently slide a small flat blade jeweler's screwdriver into it to make sure its clear make sure it's small diameter to prevent damage.

If you don't get a spark at the plug and have tried a new plug and checked for loose wiring without success, this module may be at fault and need to be replaced. A by-product of combustion is water vapor, but you normally only see this on frosty days from, e. The problem is likely a fuel delivery issue due to the carb not being able suck fuel when the choke is open.