B&S rebuild, new carb, won't start without starting fluid

hcliffe

Member
Joined
Jun 2, 2016
Threads
3
Messages
17
  • / B&S rebuild, new carb, won't start without starting fluid
I'm trying to get an old mower running. Model is 917.377130, 6hp. It had very few hours on it, got it from an estate. I put a new carb on it from Amazon. Not sure I hooked up the linkages correctly.
If I push the primer 3 times it won't start. If I spray starting fluid in, it runs fine. I shut it off after running only briefly and have to use starting fluid again. With the throttle all the way on fast/start, shouldn't the carb door be closed to choke it? It's not doing that, its not closing no matter what position I put the throttle in. Thoughts? Is there a video or photos that show me how to hook up the linkages? I tried searching but can't find any good videos. Thanks for any help.
 

Scrubcadet10

Moderator
Staff member
Joined
Sep 24, 2017
Threads
265
Messages
6,628
  • / B&S rebuild, new carb, won't start without starting fluid
okay from the diagram it appears you have a model 12 quantum engine,
Now, lets get some terminology straight, You said it has a primer, but then mention a choke door (choke plate), on these briggs, you either have a Primer and no choke, or a Choke and no primer.
So does your carb look like this one 1636495646335.png Or this one, 1636495696470.png with a throttle shaft and choke shaft?

Now, the problem could lie within the amazon carburetor, as it is not uncommon for them to sell Duds from the factory at a discounted price.
The diagram shows it originally as having a Primer/ no choke carburetor.
Anyway, to the meat and potatoes of the problem,
It is running too lean to start properly (lean mean not enough fuel), whenever you press the primer bulb, you should see fuel squirt up out of the main jet.
Craftsman 917377130 gas walk-behind mower parts | Sears PartsDirect
 

Fish

Lawn Pro
Joined
Aug 2, 2013
Threads
11
Messages
5,143
  • / B&S rebuild, new carb, won't start without starting fluid
That model, if it is the carb with the primer bulb, is known for primer problems. The problem is that the air cleaner base need to make a tight seal, as that is the passage that sends a puff of air to the carb and put up a pulse/squirt of fuel into the carb throat. I always put a smear of gasket sealant on the gasket between the air cleaner and carb, but be careful to not plug up any passages with sealant. This usually works.
If it is fixed, you will see a gush of fuel pop up when you push the bulb.
 

hcliffe

Member
Joined
Jun 2, 2016
Threads
3
Messages
17
  • / B&S rebuild, new carb, won't start without starting fluid
okay from the diagram it appears you have a model 12 quantum engine,
Now, lets get some terminology straight, You said it has a primer, but then mention a choke door (choke plate), on these briggs, you either have a Primer and no choke, or a Choke and no primer.
So does your carb look like this one View attachment 58908 Or this one, View attachment 58909 with a throttle shaft and choke shaft?

Now, the problem could lie within the amazon carburetor, as it is not uncommon for them to sell Duds from the factory at a discounted price.
The diagram shows it originally as having a Primer/ no choke carburetor.
Anyway, to the meat and potatoes of the problem,
It is running too lean to start properly (lean mean not enough fuel), whenever you press the primer bulb, you should see fuel squirt up out of the main jet.
Craftsman 917377130 gas walk-behind mower parts | Sears PartsDirect
My carb is like the first one you show. I did not replace the primer bulb, maybe I need to try that. So I should be able to look into the carb while I push the primer bulb and see fuel squirt in? Should the choke plate be closed when I try to start it? Or does this have an automatic choke?
 

hcliffe

Member
Joined
Jun 2, 2016
Threads
3
Messages
17
  • / B&S rebuild, new carb, won't start without starting fluid
That model, if it is the carb with the primer bulb, is known for primer problems. The problem is that the air cleaner base need to make a tight seal, as that is the passage that sends a puff of air to the carb and put up a pulse/squirt of fuel into the carb throat. I always put a smear of gasket sealant on the gasket between the air cleaner and carb, but be careful to not plug up any passages with sealant. This usually works.
If it is fixed, you will see a gush of fuel pop up when you push the bulb.
I should be able to see a gush of fuel pop up? Where would I see this? can I see it with the air filter on?
 

Scrubcadet10

Moderator
Staff member
Joined
Sep 24, 2017
Threads
265
Messages
6,628
  • / B&S rebuild, new carb, won't start without starting fluid
since you have the first carb I pictured, you don't have a choke and are most likely referring to the Throttle and throttle shaft. With the engine sitting, not running, it should be wide open.
 

hcliffe

Member
Joined
Jun 2, 2016
Threads
3
Messages
17
  • / B&S rebuild, new carb, won't start without starting fluid
since you have the first carb I pictured, you don't have a choke and are most likely referring to the Throttle and throttle shaft. With the engine sitting, not running, it should be wide open.
So does the choke plate ever close? If so, when?

Thanks everyone for the input so far.
 

slomo

Lawn Pro
Joined
Jul 14, 2019
Threads
78
Messages
5,054
  • / B&S rebuild, new carb, won't start without starting fluid
Choke that word out of your word box. You have no choke.
 

Richard Milhous

Well-Known Member
Joined
Aug 2, 2021
Threads
6
Messages
173
  • / B&S rebuild, new carb, won't start without starting fluid
The choke depends on the muffler bearing for proper operation. Go to your nearest repair shop and ask them for a muffler bearing.
 

slomo

Lawn Pro
Joined
Jul 14, 2019
Threads
78
Messages
5,054
  • / B&S rebuild, new carb, won't start without starting fluid
Or a box of grid squares.
 
Top