Idles smooth, doesn't at higher rpms...??

[dart451]

Just threw a new carb on a Tiller/briggs and stratton 205cc, 122002-3783-B8. It starts and idles perfectly but when I give it more throttle, it misses. I checked to see if it was perhaps not getting enough fuel by giving it a little choke but it just chokes out and doesn't smooth. I've never heard this engine run before so I'm not sure if it was like this with the older carb. I changed out the carb because the old one was sitting for 5 years with fuel in it. I did clean the tank completely out and have fresh fuel. Anyone have a clue what else I might check here? Just for information, the tiller looks almost brand new...I think it was only used once...Thank you...

[KE4AVB]

Try pulling the muffler as it has been sitting 5 yrs and the mud wasp may have partial plugged it. Just a thought.

[dart451]

Thank you, I'll try that!

[Arkie]

Check the obvious first.

Like new spark plug gapped correctly and the kill wire not rubbing against the frame

Which Briggs part number carb did you remove and the part number you installed? I seen maybe two different carbs for that engine.

Does the carb have a adjustable jet for High end?

[dart451]

Ok, muffler ok...does have a mesh screen but it was all clear. The carb I replaced it with was a 591925 carb. There is no adjustment screws except idle. I will clean the plug and look for loose kill wires...

[dart451]

Plug gap good, even tried new spark plug, kill wire looks stable...I think I'm gonna order another carburetor for this machine...

[hanz63]

Bear in mind to that these small OHVs have weak valve springs. It doesn't take much residue on the stems- IE old fuel gum which makes them not work so free as things get wound up.

[Arkie]

Plug gap good, even tried new spark plug, kill wire looks stable...I think I'm gonna order another carburetor for this machine...

Couple hints:

Might think about adding a fuel filter before you install the next new 591925 carb.

You might also see if you can clean the High speed area of the carb, if the new carb gets a good run. It's the one you see located in the center after you remove the bowl. Itty bitty trash from a old fuel line shedding or gas tank will upset this area easily, especially on the non-adjustable type carbs.

Some (not all) of them little carbs have a sealing gasket between the end of the H jet area and the bottom of the bowl. If it leaks or bad (or not installed) they will idle good but no High run.

At least it's not a expensive carb.

[dart451]

Thank you for the additional information! I will be removing the carb today and see if I can clean out the H jet...

[dart451]

Ok, took the carb off, didn't see any dirt in the bowl but I used my welding wires to clean out all orifices and blew everything out. I also placed a filter from the fuel tank to the carb. Still misses a bit at speed. I should be getting another carb in a few days...will report...