B & S 3.75 stops after 20 minutes

PW question · 05-16-2008, 12:59 PM

Hello,

I am trying to troubleshoot the B & S 3.75 engine on a small Sears pressure washer. The engine will run fine for about 20 minutes, then stop abruptly. I removed the fuel tank and rinsed it out. It looked pretty clean. I noticed that the rubberized plastic gasket between the carb and tank has a little pillow type thing and it looks like the seam closest to the engine is split. I carefully put everything back together and added clean fuel. It ran for 30 minutes without a problem.

So, the questions:

What is the purpose of the pillow/gasket thing and is supposed to have the split.

Will old fuel cause the engine to stop running abruptly after 20 min and why?

Thanks in advance for your expertise

**K-B** · 05-19-2008, 06:07 PM

I think you're talking about the diaphragm, if that is damaged in a critical place it won't suck fuel properly. Old fuel should not cause the engine to repeatedly quit running.
So the problem is fixed now?

05-16-2008, 12:59 PM	#1 (permalink)
PW question Registered User Join Date: May 2008 Posts: 1 OS: xp	B & S 3.75 stops after 20 minutes Hello, I am trying to troubleshoot the B & S 3.75 engine on a small Sears pressure washer. The engine will run fine for about 20 minutes, then stop abruptly. I removed the fuel tank and rinsed it out. It looked pretty clean. I noticed that the rubberized plastic gasket between the carb and tank has a little pillow type thing and it looks like the seam closest to the engine is split. I carefully put everything back together and added clean fuel. It ran for 30 minutes without a problem. So, the questions: What is the purpose of the pillow/gasket thing and is supposed to have the split. Will old fuel cause the engine to stop running abruptly after 20 min and why? Thanks in advance for your expertise

05-19-2008, 06:07 PM	#2 (permalink)
K-B Moderator/Gearhead Join Date: Oct 2005 Location: NY Posts: 2,725 OS: Ubuntu 8.04 My System	Re: B & S 3.75 stops after 20 minutes I think you're talking about the diaphragm, if that is damaged in a critical place it won't suck fuel properly. Old fuel should not cause the engine to repeatedly quit running. So the problem is fixed now? __________________ Registered Linux User #435503 Don't let socialists take over this country. Vote Nobama 2008!