Carburetor Part Unknown
#1
02-24-19, 04:01 PM
Carburetor Part Unknown
My riding mower, Troy-Bilt 13AN77KS, has had problem starting up. And when it does start up, RPM goes up/down, backfires, and dies.
It has Brigggs & Stratton engine, and I've removed the carburetor. Although it was fairly clean, I attempted to clean anyways. While cleaning, a part fell out and I'm not sure where it belongs. I've marked the part in red box. Please help.
It has Brigggs & Stratton engine, and I've removed the carburetor. Although it was fairly clean, I attempted to clean anyways. While cleaning, a part fell out and I'm not sure where it belongs. I've marked the part in red box. Please help.
#2
02-24-19, 05:31 PM
Member
It goes in center hole of white plastic part in pic.
Don't remember which orientation, but should be obvious with parts in hand and looking at them.
RR
Don't remember which orientation, but should be obvious with parts in hand and looking at them.
RR
#3
02-24-19, 10:32 PM
Forum Topic Moderator
Looking at the white plastic part from the view in the first photo, insert the brass jet down in the center hole small end first. While you have it apart, poke a very fine wire like one plucked from a wire brush into the small hole in the carburetor right next to the brass pickup tube. There is a tiny jet in there, make sure the wire goes through it. That is often the cause of surging on these carbs.
#4
02-25-19, 09:14 PM
Seems to fit in the center perfectly. Finally got the carburetor put together. Tomorrow, I'll charge up the battery and see if it cranks up.
Thank you both.
Thank you both.
#5
02-27-19, 01:36 PM
It cranked up and running!!!!! 
But the throttle lever isn't making any difference when moving from Fast to Slow. According to some videos, it supposed to be very loose with no tension at all. But mine, although it's much looser, it still has plenty enough tension to return back. How loose is the throttle supposed to be when on Slowest position?
Also, on the photo, I had to turn the "A" screw (idle adjustment) all the way in to keep the engine steady, otherwise engine runs high/low erratically and sometimes die. And turning "B" (fuel mix? only turns 1/4 each direction) doesn't seem to make any difference. The engine also seem to have small (not very loud) backfires.
I've changed oil, replaced the spark plug, fuel filter and air filter. What else can I do to make this run more smoothly? I'm using fuel stabilizer, and even tried seafoam, but not making any difference.
But the throttle lever isn't making any difference when moving from Fast to Slow. According to some videos, it supposed to be very loose with no tension at all. But mine, although it's much looser, it still has plenty enough tension to return back. How loose is the throttle supposed to be when on Slowest position?
Also, on the photo, I had to turn the "A" screw (idle adjustment) all the way in to keep the engine steady, otherwise engine runs high/low erratically and sometimes die. And turning "B" (fuel mix? only turns 1/4 each direction) doesn't seem to make any difference. The engine also seem to have small (not very loud) backfires.
I've changed oil, replaced the spark plug, fuel filter and air filter. What else can I do to make this run more smoothly? I'm using fuel stabilizer, and even tried seafoam, but not making any difference.
Last edited by itchibahn; 02-27-19 at 02:01 PM.
#7
03-19-19, 08:38 PM
By turning the idle screw all the way in, you are bypassing the pilot circuit and that is the only reason it is running. It's also the reason your throttle is making no difference. You need to take the carb back apart and clean all the passages real well.
#8
03-20-19, 05:42 AM
You could also get a rebuild kit. All it takes is a leaky o-ring or gasket to cause issues. Although these carbs are so inexpensive you may as well just buy a new one and be done with it. I believe you can get a brand new one for under $30.
