Hey all, first time poster in need of some help.

My truck has developed an attitude lately, starting after my first attempt at a carb rebuild. Following a video on YouTube by William Archibald, I got the correct kit and replaced all the gaskets, accelerator pump diaphragm, and various other pieces included in the kit including the float needle, ball bearing, and mesh filter. Following the video, everything appeared to be clear and understandable, so I had it apart, cleaned, and back together in about 2 hours.

Now, when I try to start, sometimes the engine fires right up then will die a few seconds later. Sometimes I can keep it running if I hold the throttle to the floor. Initially, I assumed I flooded it by pumping the gas too many times. After that, I replaced the spark plugs, added dielectric grease, and replaced the oil. However, something else must be wrong, as it still exhibits the same symptoms. I took the top off the carb on the engine and noticed the float bowl is nearly empty even immediately after attempting to start. Sometimes, I would hear a tapping coming from the carb after attempting to start as well.

I've looked around on the forums here and online and am not sure where to begin to identify the cause of the issue. Any suggestions? Thanks for reading this far!

 

Alright, a few videos in and I’ve come across another with similar symptoms. One noted that the float bowl empties minutes after running and they identified that it was a bad power valve dumping fuel into the engine.

I have some free time tomorrow after work and plan to take the carb off again and check this out. I also think I’ll clean the float bowl and needle valve again while in there and check that it seats properly.

I just hope I don’t need to change my oil again if it’s been dumping fuel into the cylinders.

 

If this condition all started after you rebilt the carb, you must have done something wrong. Look more closely at the needle, seat and float assembies. Don't overlook the operation of the choke and choke pull off.

If the oil doesn't smell of gas, your fine with it.

 

Pretty common for someone to forget the placement of the spring wire that goes in the groove in the needle and seat
Also pretty common to scratch a phenolic float and make it soak up fuel and get heavy
Maybe watch a few videos on overhauling that carb
While the fuel line is off, you can manually check the operation of the needle and seat, do that before you run it again
Make sure that when the float is up or the carb is turned upside down, the needle and seat is closed

 

The float drop measurement is as critical as the float level adjustment
If the float drops too far, the float can stick in the down position
Pretty common if you replace the float and do not check the drop measurement

 

Thanks for all the points so far. I finally tore into it tonight and am pretty sure I found the issue. The power valve cover was filled with gas on the vacuum side, indicating the gasket failed.

Looking closely at the gasket, it appears spilt along the horizontal plane which I figure led to unmetered fuel being sucked into the carb. That explains my empty float bowl condition in addition to the flooding symptoms.

I appreciate the pointers on some other things to check, and will make sure to address all them before putting it back in. Hopefully I’ll have some more time tomorrow to get it fired up.

 

What I ended up doing was picking up a pack of Viton o-rings from HF and using that as a gasket on the power valve. I had read up that these are suitable for gas contact and would hold up to vacuum better than the paper like material from the gasket kit I got.

That did the trick. Fired right up and idled smoothly. I still need to pick up a vacuum line from the store for the choke pull off but otherwise think Im in good shape now.

I can’t tell if I smell gas in the oil, or if thats the lingering smell from last week. Last time there was so much fuel mixed in, the oil drained like water. I might change the oil again to be on the safe side.

 

1) Thanks for following up with the final fix! I hate it when you find a thread with your exact problem but no answer!

2) So I fly piston engine Cessnas. It is right in the owner's manual that when it it really cold out to put a quart of gas into the oil to thin it out and allow the engine to crank easier. Don't worry it says, when the engine gets up to operating temp the gas will evaporate out of the oil.

Food for thought!