Gas getting in the oil

redlined_b16a · 08-25-2009, 06:16 PM

I have a 21hp Briggs & Stratton OHV V-Twin I/C
Model#403677
Type#0343 E1
Code# 041103YG
Family# 5BSXS.742VF 276023

When I got the engine the oil level was too high,I drained the oil,It was 90% gas,after the oil was taken care of,she runs great,fires right up.If I leave it sit overnight,the next morning the cylinders will be flooded with fuel and it will be hydrolocked,once the cylinders are flushed out,runs perfectly.I have tested the fuel shut off solonoid and evrything looks new in the carb.If i install a fuel shut off valve inline,As long as I shut the valve off when its not running it wont be a problem,but I want to sell the Mower so I have to fix the problem.

heres the questions
What is causing the crankcase to fill with gas?
With the fuel solonoid closed....how is gas flooding the cylinders?

**K-B** · 08-26-2009, 07:27 AM

Sounds like the inlet needle (activated by the float) is staying open a bit, probably either has a piece of dirt caught between it and the seat or the needle tip or seat is damaged.

snowballer · 08-26-2009, 09:36 AM

I'm a newbie on this site but I'd say its the needle and seat as well.

Back in the day Skidoo had the same problem.

And every once in a while you'll run acrossed a newer one that has that problem.

redlined_b16a · 08-26-2009, 10:26 AM

The needle,seal looks fine,I think I will check the fuel pump,If the diaphram is leaking it will leak into the right valve cover

**K-B** · 08-26-2009, 10:28 AM

Quote:

Originally Posted by redlined_b16a

The needle,seal looks fine,I think I will check the fuel pump,If the diaphram is leaking it will leak into the right valve cover

Yes, that's possible, but kinda rare for that style pump. I would thoroughly clean the inlet area with solvent and compressed air (even a tiny speck of dirt will cause the needle not to seat) , and check the float for any cracks or leaks.

redlined_b16a · 08-27-2009, 01:36 PM

I re cleaned the carb,seems ok,i'll know later after it sits for awhile with fuel in the tank.I adjusted the rockers to .004,they were way off.It seems like my battery isnt enough to crank it,It barely starts the engine,I assume I need a battery with 300 cranking amps rather than the 150 I have now.

**K-B** · 08-28-2009, 08:04 AM

Yes, you should have a battery with 300 CCA

08-25-2009, 06:16 PM	#1 (permalink)
redlined_b16a Registered User Join Date: Aug 2009 Posts: 23 OS: vista	Gas getting in the oil I have a 21hp Briggs & Stratton OHV V-Twin I/C Model#403677 Type#0343 E1 Code# 041103YG Family# 5BSXS.742VF 276023 When I got the engine the oil level was too high,I drained the oil,It was 90% gas,after the oil was taken care of,she runs great,fires right up.If I leave it sit overnight,the next morning the cylinders will be flooded with fuel and it will be hydrolocked,once the cylinders are flushed out,runs perfectly.I have tested the fuel shut off solonoid and evrything looks new in the carb.If i install a fuel shut off valve inline,As long as I shut the valve off when its not running it wont be a problem,but I want to sell the Mower so I have to fix the problem. heres the questions What is causing the crankcase to fill with gas? With the fuel solonoid closed....how is gas flooding the cylinders?

08-26-2009, 07:27 AM	#2 (permalink)
K-B Moderator, Linux Join Date: Oct 2005 Location: NY Posts: 2,878 OS: Vista, Ubuntu My System	Re: Gas getting in the oil Sounds like the inlet needle (activated by the float) is staying open a bit, probably either has a piece of dirt caught between it and the seat or the needle tip or seat is damaged. __________________

08-26-2009, 09:36 AM	#3 (permalink)
snowballer Registered User Join Date: Aug 2009 Posts: 6 OS: vista	Re: Gas getting in the oil I'm a newbie on this site but I'd say its the needle and seat as well. Back in the day Skidoo had the same problem. And every once in a while you'll run acrossed a newer one that has that problem. Last edited by snowballer; 08-26-2009 at 09:38 AM.

08-26-2009, 10:26 AM	#4 (permalink)
redlined_b16a Registered User Join Date: Aug 2009 Posts: 23 OS: vista	Re: Gas getting in the oil The needle,seal looks fine,I think I will check the fuel pump,If the diaphram is leaking it will leak into the right valve cover

08-27-2009, 01:36 PM	#6 (permalink)
redlined_b16a Registered User Join Date: Aug 2009 Posts: 23 OS: vista	Re: Gas getting in the oil I re cleaned the carb,seems ok,i'll know later after it sits for awhile with fuel in the tank.I adjusted the rockers to .004,they were way off.It seems like my battery isnt enough to crank it,It barely starts the engine,I assume I need a battery with 300 cranking amps rather than the 150 I have now.

08-28-2009, 08:04 AM	#7 (permalink)
K-B Moderator, Linux Join Date: Oct 2005 Location: NY Posts: 2,878 OS: Vista, Ubuntu My System	Re: Gas getting in the oil Yes, you should have a battery with 300 CCA __________________