Yf Flooding

Finally got my restoration nearly complete. Recently rebuilt the YF carb with a kit from Walcks with the Viton tipped needle. Took it on a test drive. Did fine for about 5 min and then started coughing and died. Pull over and popped the hood and gas was pouring out of the carb. Waited a few min and finally got it started by keeping the pedal to the floor. Barely got home by keeping the rpms high. Let off the gas in the driveway and it died. Coasted into the garage thankfully. Popped the hood and, yep, flooding like crazy. All the threads on here talk about the spring loaded needle and seat. Where do I get one???

 

This is a stuck float. Don't know about the YF, but I have found that alignment where the float rides on the needle matters to the needle opening and closing smoothly. I expect the spring loaded needle is more about off-road use than around town. The spring dampens the float movement over bumps and jolts, and keeps the float from bouncing open too much and (typically) flooding through the bowl vents. I would not expect it to help on the street.

If you run into this again, the immediate fix is to rap on the side of the carburetor with a screwdriver or hammer handle or such. You'd aim to free the float to rise and hold the needle closed.

 

Also check for debris between the needle and seat. Something may have come loose or gotten in the fuel system while work was being done.

 

Read this while you have it apart:

http://www.earlycj5.com/xf_cj5/index.php?threads/139131/

 

Thanks for the info. I’ll tear it down and let you know what I find. Happy 4th!!

 

Also note that the different YF needles and seats have differing height adjustments, which is critical. The generic rebuild kits can have poor data on this.

Be careful not to misplace the accelerator-pump check ball or weight. A common issue.

YF needs a fuel pressure of no more than 2.5 or 3 psi.

 

Well I couldn’t wait so I just took it apart.
1. There was a big piece of junk between the needle and seat
2. The float was adjusted to 5/16, per the prior rebuild instructions

Based on the info in the link posted by Jw60 I readjusted the float to 15/32. Also cleaned out some debris from the float bowl. Put it all back together and zipped around the neighborhood - no issues!!
Thanks everyone for your help.
Next step is to get an inline fuel filter. I didn’t put one in because I could decide where to cut my nice new (expensive!) pre-bent fuel lines. Any suggestions?

 

All good information. One other thing to check is the pin which allows the float to rise and fall. It may be worn.

 

Somewhere close to the carburetor and accessible. Fram G-1 or equivalent. I would support the line on both sides of the filter.

Type G1 into RockAuto and they give a dozen alternatives.
https://www.rockauto.com/en/moreinfo.php?pk=577845&jsn=266

 

I like to place it between the tank and the pump. While this isn't as efficient (pumps are pushers not suckers), it does keep any debris out of the pump check valves.

 

Can the under-seat tank accept a strainer? Later tanks put a screen in the tank to prevent chunks from reaching the fuel pump. Suggest the pump will pass tiny particles that the G-1 style filter is meant to remove. No back pressure and both the fuel pump and the carburetor are protected.

 

I have run a Napa 3031 fuel filter between the tank and pump on my f head for years, along with a pressure regulator between the pump and carb, without any issues. (This may not be correct, but always willing to learn from those with more wisdom)

 

The bottom style pickup is simply an upside down J of tubing. Unless you cut a big hole in the top of the tank you don't have enough access to it to do anything.
It's a lot easier to plug it and use a tractor petcock / sediment bowl with strainer.

I did overkill with a boat filter before the pump but I've got other variables in play.

 

I have a cleanable glass filter in-line before the pump. Works for me. I really like being able to monitor the flow, and see what is going on, such as any water or contaminants.

 

I haf a fuel pump that was pumping way to high fuel pressure. I installed a pressure regulator between the pump and the carburetor and s filter before the pump. A carb rebuild kit and now everything seems fine.