Briggs Inlet Seat Installation


Old 03-27-10, 01:26 PM
Thread Starter
Join Date: Nov 2004
Location: USA
Posts: 88
Question Briggs Inlet Seat Installation

Briggs Engine 11 HP 252700-0620-01 on Riding Mower

The instructions for installing the Briggs inlet seat say the groove side goes "down". Does that mean the groove goes down against the carb body or does that mean that the groove points down towards the needle?

Background. Mower had sat for a couple of years before I got it. Carb was a mess - all gummed up. Soaked in can of carb fluid for 24 hrs. It took that long to get all of the gunk loose. Used compressed air to blow out all of the small holes.

When i reinstalled the carb, gas leaked out of the carb (flows up the carb nozzel and out of the carb) indicating either the needle/seat were not working or the float was bad. Float was fine - no holes.

Purchased a new needle and seat. I installed the groove side of the needle down towards the carb body. Wire end of the needle holder points away from the venturi. Gas still leaks.

Removed bowl and needle in case some dirt was causing the needle not to close. Renstalled bowl and needle. Gas still leaks.

So, did i install the needle seat correctly or does the groove point down towards the needle.

What else can cause gas to leak out of the carb other than a bad needle/seat, bad float or dirt?
Sponsored Links
Old 03-27-10, 02:25 PM
Join Date: Nov 2005
Location: USA
Posts: 468
You installed the seat correctly. If the float bowl vent is still blocked than that would cause your symptoms.

Old 03-27-10, 02:36 PM
Thread Starter
Join Date: Nov 2004
Location: USA
Posts: 88
I'm not familiar with the vent. I assume it is a passageway from the bowl to the upper part of the carb. Do i just need to spray carb fluid in any holes that i see?
Old 03-27-10, 02:39 PM
Thread Starter
Join Date: Nov 2004
Location: USA
Posts: 88
Disassembly of Briggs and Stratton Large One-piece Flo-jet Carb

I just found the link above that has the exact carb I'm dealing with. It has a good pic of the vent.

I'll clean it out and see what happens.

thanks for your help.

Old 03-28-10, 08:48 PM
Join Date: Oct 2007
Location: ontario,canada
Posts: 325
did you check float adjustment?
Old 03-29-10, 05:19 AM
Join Date: Nov 2007
Location: NE Okla
Posts: 432
is the float in good condition? i.e., does not have pinhole in it? such that fuel can enter float?
this will cause float not to raise needle to shut off fuel flow.
Old 03-29-10, 08:16 AM
Thread Starter
Join Date: Nov 2004
Location: USA
Posts: 88
I checked the float and it does not have any pin holes in it.

also, I checked the float adjustment and slightly bent out the tang so that the needle would close just a little earlier. neither of these fixed the problem.

I removed the carb and tested the float in a container of water. The float closed the needle correctly.

After blowing out the vent and testing it in water, I'm going to reintsall the carb and see if the problem is fixed. Will keep you posted.
Old 03-30-10, 08:43 PM
Thread Starter
Join Date: Nov 2004
Location: USA
Posts: 88
Carb problem has been fixed. Either the vent was blocked or some dirt was keeping the needle from sealing the seat. Either way, the carb is no longer leaking any gas.

Thanks for all of the tips and suggestions.
Old 04-24-10, 08:16 AM
Join Date: Apr 2010
Location: usa
Posts: 3
Inlet valve seats

Does anyone know where to obtain inlet valve seats for Walbro LMT 5-4993 without haing to buy compete o'haul kit ?
Old 04-24-10, 08:58 AM
indypower1's Avatar
Join Date: May 2009
Location: Lake Winnipesaukee, New Hampshire
Posts: 634
Most of the time you can buy a needle & seat. Can you post the engine numbers? With that info we can get you the part number.
Old 02-13-11, 12:45 PM
Join Date: May 2007
Location: USA
Posts: 93
I have the exact same carb (shown here: Disassembly of Briggs and Stratton Large One-piece Flo-jet Carb ). It runs fine but leaks gas.

I bought a stock B&S fuel inlet valve and seat kit (p/n 394681):
Illustrated Parts Lists | Repair Parts & Maintenance Products | Shop | Briggs & Stratton

The kit has no brass seat in it. It just has the valve (2; one is viton-tipped), the clip, and a little viton "ring", which looks like it could fit inside of my old inlet seat. Instructions that came with the kit do not discuss the seat or what to do with the viton ring. Don't I get a new seat? I thought I had to remove the old seat with a tap screw and press in a new seat. Will the viton "ring" work if I put it inside the old seat?
Thanks for any help!

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes