Float bowl removal 18.5 hp B&S

dadurlingJuly 23, 2010

I've been reading lots of posts about surging/stalling B&S engines. I've got the same issue with a JD L108 and its B&S 18.5 hp Intek engine (31P777) so I thought I'd start by cleaning out the carb. However, I cannot seem to loosen the float bowl screws, nor can I remove the thing that holds the fuel solenoid at the bottom of the float bowl. Any suggestions?

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I have a very thin end wrench that I remove the carb solenoid with. It is a normal, right hand, thread and must come off to clean the carb bowl.

" I cannot seem to loosen the float bowl screws,"

There are no float bowl screws. There are two long studs that extend thru the both sides of the carb holding it to the Intake Manifold.

Walt Conner

    Bookmark   July 23, 2010 at 9:58PM
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Well my mistake, the NIKKI carb does have two screws holding the float bowl.

Walt Conner

    Bookmark   July 24, 2010 at 8:38PM
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A lot of the 28's & 31's utilize the Nikki carb with two crews. I let the screws soak with blaster then use a really good phillips head. The Nikki's run lean even clean, leaving the engine bouncing off the governor. If you can, break the cap of the pilot air screw on top of the carb and remove it to clean, then set it about 1 1/2 turns from its seat. This will let you dial in the carb nicely.

    Bookmark   July 25, 2010 at 7:53PM
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Walt, or anyone, does the pilot air screw on the Walbro (B&S 31H777) on a Poulanpro 42" adjust the same as the Nikki? Mine has a black plastic tamper proof cap on it. I tryed to look up the adjustment and got the message "This carb does not require adjustment" or words to that effect. Also on the valve lash adjustment, Does it take a 5mm box end and a what size torkx or allen wrench to loosen the set screw?
And is the cold engine adjustment .004" feeler gage?

    Bookmark   July 27, 2010 at 4:06PM
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The limiter cap will come off. Check first that the mounting bolts between the Intake Manifold and the head are not loose and gasket leaking. Spray WD40 or something similar around joint.

I have detailed Instructions on adjusting the valves but they do not include the size of the wrench nor the torx head locking screw.

Walt Conner
wconner5 at verizon dot net

    Bookmark   July 27, 2010 at 9:41PM
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