I'm At A Loss!!!

ChrisBFRPKY

Active Member
Joined
Sep 24, 2020
Threads
0
Messages
51
Yep, head gasket. If you're using the aftermarket plastic fuel pumps, buy the ten pack, you'll need them.
 

TobyU

Well-Known Member
Joined
Jun 1, 2014
Threads
0
Messages
563
The order for the diagnosis got all messed up here.
Throwing Parts at it like replacing the fuel pump thinking it's going to fix the problem hardly ever does so you should never replace a part until you're absolutely certain or really close to certain that is bad.
Should have done more research on it before replacing anything because just because it only cost $7 ship to your door from amazon, doesn't mean you should do it and it doesn't mean it's worth the chance. Lol
The two common causes of oil coming out of that brass filter in the fuel pump would be a blown head gasket or thinned out oil due to fuel dilution into the crankcase or what they call fuel migration.
Fuel migration is caused by a needle and seat that doesn't shut off completely when the engine stops running and the float raises up so it continues to flood out the throat of the carburetor and depending on where the engine stops with the piston and the cylinder, it can flood the cylinder completely and then find its way past the rings in just a few minutes and you can end up with a quart of gas into your oil.
This requires either a new carburetor or some attention to the needle and or seat which should mean replacing them both so you have two new sealing areas.
Some people cheat I just replace the needle valve and sometimes they get by for a long time but sometimes it looks down in a month or a week or overnight and it starts leaking again and they have the same problem and they just wasted another quart and a half of oil.

You can use one of the little thumb fuel shut offs to prevent this but it's best to fix the problem because you will soon forget to turn off the fuel shut off and it will happen again.

A common sign of this happening is you no longer have to choke the engine to start it. In fact it's hard to start and it blows a big puff of smoke soon as it starts and then clears up or you have to turn the choke off to get to start.

If this is not the problem it's not doing any of this and the oil is not above the level that previously was and then that by gas then it's likely a blown head gasket which is probably the more common of the two.
Pretty much all of these brakes overhead valve 31 and 33 series engines will do this eventually.
It's not a matter of if but when.
It's a terrible design on the right side when you're looking at it by the lifter galley with too much space between the two bolts and two thin of gasket and too narrow of a gasket so it blows out and then starts to pressurize the crankcase and that blows oil out that hole since the fuel pump is connected too the crankcase so I can get its pulse alternate between vacuum and pressure so it can move the little rubber diaphragm inside so it can actually create the pumping action for the fuel.

You can check your plug and see if it's getting black wet City stuff on it which is a sign of the head gasket too and I have found one of the best ways to check for a blown head gasket is to get the more up to operating temperature and ride around in a tight circle to the left three times as fast as you can and then go to the right three times as fast as you can and then back to the left three times as fast as you can..
It sounds funny but usually this will flash the oil enough that you'll get a big white poof of smoke so much it looks like a mosquito fogger and you can't see your house.
I've also found that if you run it at 3/4 speed or at least a little over half speed when it's warm and slowly lift the dipstick up about an inch and a half it will often cause it to suck some oil through and start smoking also and if you notice a lot of pressure coming out of the dipstick it's probably blown too but they all have a little bit of pressure out of the dipstick because they're doing that suck blow suck blow suck blow thing.
 

jetsticks

Member
Joined
Mar 25, 2019
Threads
3
Messages
22
The order for the diagnosis got all messed up here.
Throwing Parts at it like replacing the fuel pump thinking it's going to fix the problem hardly ever does so you should never replace a part until you're absolutely certain or really close to certain that is bad.
Should have done more research on it before replacing anything because just because it only cost $7 ship to your door from amazon, doesn't mean you should do it and it doesn't mean it's worth the chance. Lol
The two common causes of oil coming out of that brass filter in the fuel pump would be a blown head gasket or thinned out oil due to fuel dilution into the crankcase or what they call fuel migration.
Fuel migration is caused by a needle and seat that doesn't shut off completely when the engine stops running and the float raises up so it continues to flood out the throat of the carburetor and depending on where the engine stops with the piston and the cylinder, it can flood the cylinder completely and then find its way past the rings in just a few minutes and you can end up with a quart of gas into your oil.
This requires either a new carburetor or some attention to the needle and or seat which should mean replacing them both so you have two new sealing areas.
Some people cheat I just replace the needle valve and sometimes they get by for a long time but sometimes it looks down in a month or a week or overnight and it starts leaking again and they have the same problem and they just wasted another quart and a half of oil.

You can use one of the little thumb fuel shut offs to prevent this but it's best to fix the problem because you will soon forget to turn off the fuel shut off and it will happen again.

A common sign of this happening is you no longer have to choke the engine to start it. In fact it's hard to start and it blows a big puff of smoke soon as it starts and then clears up or you have to turn the choke off to get to start.

If this is not the problem it's not doing any of this and the oil is not above the level that previously was and then that by gas then it's likely a blown head gasket which is probably the more common of the two.
Pretty much all of these brakes overhead valve 31 and 33 series engines will do this eventually.
It's not a matter of if but when.
It's a terrible design on the right side when you're looking at it by the lifter galley with too much space between the two bolts and two thin of gasket and too narrow of a gasket so it blows out and then starts to pressurize the crankcase and that blows oil out that hole since the fuel pump is connected too the crankcase so I can get its pulse alternate between vacuum and pressure so it can move the little rubber diaphragm inside so it can actually create the pumping action for the fuel.

You can check your plug and see if it's getting black wet City stuff on it which is a sign of the head gasket too and I have found one of the best ways to check for a blown head gasket is to get the more up to operating temperature and ride around in a tight circle to the left three times as fast as you can and then go to the right three times as fast as you can and then back to the left three times as fast as you can..
It sounds funny but usually this will flash the oil enough that you'll get a big white poof of smoke so much it looks like a mosquito fogger and you can't see your house.
I've also found that if you run it at 3/4 speed or at least a little over half speed when it's warm and slowly lift the dipstick up about an inch and a half it will often cause it to suck some oil through and start smoking also and if you notice a lot of pressure coming out of the dipstick it's probably blown too but they all have a little bit of pressure out of the dipstick because they're doing that suck blow suck blow suck blow thing.
Ok. So I have a little bit of diagnosing to do this weekend. I actually believe it’s the head gasket because from what I’ve been reading, these engines are notorious for blowing head gaskets. I will post my findings for sure. I appreciate all the help.
 

jetsticks

Member
Joined
Mar 25, 2019
Threads
3
Messages
22
Okay. Thanks to all who helped me fix this issue. After trying many different ideas it WAS the head gasket. I replaced the head gasket and there were no more leaks. Since it's getting to be cooler here now I'm not sure how much I'll be using the mower so I'll have to keep an eye on it next year. Here is an issue I ran into though. My torque wrench wasn't working so I just guestimated on the torque. Probably not a good idea but I didn't want to spend hundreds of dollars for a new one. Secondly, my feeler guage only went to .012 and I needed one to go to .004 when I was adjusting the valves. So I guessed again. This time I was wrong so I went and bought another guage that went to .004. Once set they worked just fine.
 

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
59
Messages
15,349
Guessing at head bolt torque will result in a blow head gasket very quickly. Most auto parts store have a free loaner program where you can get a torque wrench for free. There are very specific reasons for properly torquing boors and all the experienced techs on this forum will say, “ DO IT RIGHT OR DO IT OVER”.
 

slomo

Lawn Pro
Joined
Jul 14, 2019
Threads
78
Messages
5,118
Someone on your block must have a torque wrench. Got to be some gearhead down the road. Bring a 12 pack and make a new friend.
 
Top