B&G motor starting problems with a twist.

9 years ago

Hi, I have a Craftsman 6 hp model 944.360431 Briggs and Stratton motor (can't edit title) that I've been working on but am now stumped.

This mower will not start, common problem, but the difference is, if I prime the cylinder through the spark plug port, it will start....and stay running. Mow the whole lawn as long as you don't shut it off. If you allow it to stop and restart right away, it will start again, but if you wait more than 20 seconds, no way, not even a cough.

So far I have replaced the gaskets in the carb and air intake. Replaced fuel line. Replaced timing keyway (it was sheared). Cleaned the carbs completely three times with carb cleaner (completely taken apart with proper wire cleaners) Checked float operation, good.

The air pulse primer does not work, probably due to warped plastic airbox, but don't think this should be the primary issue as it won't start even after fully warmed up....

Any ideas on what else could cause the fuel starving problem? (spark plug is dry when I take it out)

Thanks.

This post was edited by CamG1234 on Sat, May 31, 14 at 10:22

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Comments (3)

bill_kapaun
9 years ago
For those that are interested, the engine should be a Briggs-
122T02-1334-B1

Does the carb have a primer bulb, manual choke or Auto Choke?

I suspect it has the Auto Choke that is malfunctioning.
I have absolutely no clue about them.
tomplum
9 years ago
Will it start w/o the air box on? With the carb inverted, does the float sit relatively level? It is easy not to get the seat not quite all the way in if you are not used to doing these- then the float level would be too low. But then again, I don't see where you had replaced the seat. Seat + carb cleaner = Bad. So do so if you haven't. Did you see the tiny hole in the brass plug on the LH side of the venturi? Inspect also the intake tube
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CamG1234
Original Author
9 years ago
I ended up making a second gasket for the airbox to carb seal. This at least let the air pulse primer start working again and I can now get it going with this.

Still not sure why you would have to prime it after its been fully warmed up, but at least I can use it now. Still not an easy start, but useable nonetheless.