oil blowing from fuel pump

larry e.

Forum Newbie
Joined
Aug 11, 2015
Threads
1
Messages
1
I have a 21 hp b&s blowing oil from fuel pump. replaced fuel pump with no improvement. any ideas?
 

ILENGINE

Lawn Royalty
Top Poster Of Month
Joined
May 6, 2010
Threads
39
Messages
10,035
Sounds like the crankcase is pressurizing. Most likely cause is blown head gasket.
 

grumpyunk

Active Member
Joined
Jul 13, 2015
Threads
0
Messages
90
I would at least check the oil level on the dipstick and give the oil a smell test. If the level is high, and the oil smells of fuel, then you may have a leaky float valve, feeding fuel to the crankcase, diluting the oil, and raising the level such that it gets blown out at the pump. Also check that the crankcase is sealed properly to prevent 'pumping' action in the crankcase, causing over pressure in the crankcase.
If you have good compression, good power, and there is no indication of oil burning in the exhaust, blue smoke, your rings are likely in good condition, so look elsewhere for a reason for the crankcase pressurizing.
tom
 

pauly50

Member
Joined
Mar 15, 2013
Threads
1
Messages
22
hi , if oil is blowing from vent hole on vaccuum lift pump on engine and a vapour is comming from oil fill tube , and engine uses oil , blows blue smoke
most liklely a blown head gasket , single ohv briggs engines are famous for it,remove valve cover- make sure valve clearance is set at 0.003 inlet ( the alloy push rod at btm ) thous and 0.005 thou ( the steel push rod at top ) these will need to be set @ 1/4 past tdc on compression stroke , then you will need to pressurize cylinder with compressed air while its at tdc compression stroke , and listen for air escaping into push rod tunnel if so blown head gasket confirmed
obtain head gasket set pull the cyl head and clean up and replace gasket , give the inlet and ex valves a quick grind and lap to seats
reassemble and let er rip cyl head bolt torgues are 250 in/lb

hope this helps

pauly50
 

Lawnranger

Well-Known Member
Joined
Apr 18, 2012
Threads
6
Messages
671
Watch this video: www.youtube.com/watch?v=NM28FSoUGLQ The first part is just for laughs but he does talk about oil coming out from the fuel pump vent and presents a good example of how to go about a proper repair.
 

Michael72

Well-Known Member
Joined
Jan 19, 2015
Threads
16
Messages
147
Head gasket for sure....
 

Lawnranger

Well-Known Member
Joined
Apr 18, 2012
Threads
6
Messages
671
lol...thats one funny vid!!

Glad ya liked it. While I don't agree 100% with everything he does, his videos are funny and informative. If you have some time you should check out his channel and watch a few more.
 

Michael72

Well-Known Member
Joined
Jan 19, 2015
Threads
16
Messages
147
Glad ya liked it. While I don't agree 100% with everything he does, his videos are funny and informative. If you have some time you should check out his channel and watch a few more.


....the end of vid cracks me up!:laughing:... good laugh to start the day!!....
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,705
Not quite as funny as it looks.
Firstly he omitts to show the removal of the very hard to see tiny black self tapper on the inside of the inlet manifold through the air fliter chamber floor.
HE tells you to clean up the surfaces then shows you a hard heavy wire brush in a die grinder.
Use that on the combustion chamber, fine, Use it on the joint faces and you will be in trouble. You clean that face with a scotch brite pad, nothing harder.
He omitts to tell you to check the head for undercuts where the gasket has been leaking.
He also omits to tell you to lap the head and if you do not lap the head on an Intek, it will be back for a warrantee head gasket replacement before the end of the season.
This is a lot more imortant than faffing around with the valves.
I have done better than 60 intek head gaskets and never found a loose guide.
OTOH the first 3 I did came strait back, blown again.
When I first stated doing this full time it was a very steep learning curve.
While any 1/2 reasonable mechanic should be able to repair small engines, there are a lot of little things that once known make the difference between profit & loss.
If you have no idea of what you are doing Taryls vids might be encouraging, but the lack of detail and the ommissions make them problematic.
It is a well know teaching technique to add a lot of humour to lessons so he is on the right track, just a little sloppy particularly when comparred to some one like Donny Boy.
It seems like his main aim is to be funny rather than factual.
The first one I saw ( been through all of them ) I though that he was just taking the piss out of all the back yard ego maniacs posting twaddle but after a while it was obvious he was trying the be helpful , not just sarcastic.
 
Top