Primer bulb


Old 03-05-09, 04:30 AM
Thread Starter
Join Date: Jul 2003
Location: Montevallo, Alabama
Posts: 590
Primer bulb

I've got a walk/behind in with a Briggs engine m-12H802, t-2328. I have replaced the carburetor but the primer system is giving me fits. How exactly does the primer system operate? I've looked in all my Briggs manuals and I can't find any detailed information. I've even replaced the primer bulb. If I spray some fuel into the air filter opening it will start and run fine. What I need to know is just what happens whenever I press and release the bulb. I can't see if it's operating because there is a piece of metal sticking up in front of the air filter side opening. Whenever I press the bulb isn't it suppose to put a little pressure on the fuel in the bowl and spray some fuel into the throat of the carburetor?
Sponsored Links
Old 03-05-09, 06:06 AM
Join Date: Jul 2006
Location: Central New Hampshire
Posts: 754
Remove the air filter, then remove the housing form the carb.
On the back side of the housing, you will see the channel for the primer. Clean it with spray carb cleaner and blow it out completely with compressed air.
This design seems to be prone to getting plugged up due to its close proxcemity to the flying dust & dirt.
Old 03-05-09, 03:20 PM
hopkinsr2's Avatar
Join Date: Feb 2005
Location: canada
Posts: 1,561
Also make sure to replace the gasket between the filter housing & the carb. I find a lot of these torn or damaged & cause the trouble you describe.. Roger
Old 03-05-09, 06:22 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,820
I agree with Hopkins...generally primer problems with that style carb are caused by a bad gasket between the carb and air filter cover. The primer shoots through a passage on the back of the cover that is supposed to be sealed against the carb, but if the gasket is hurt the small amount of air pushed through there leaks out instead of pressurizing the bowl.

Also, if the bowl gasket is damaged or missing it may not prime right.
Old 03-05-09, 09:13 PM
Thread Starter
Join Date: Jul 2003
Location: Montevallo, Alabama
Posts: 590
Thanks fellows for the advice. The problem turned out to be exactly what you were talking about. I had to clean the small screen behind the primer bulb and also added some permatex to the gasket between the carburetor and air filter. Thanks!

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