John deere 70 carburetor issues

[Cudaman74]

Just rebuilt my carb on my 70. Ran ok before but had some small leaves around some gaskets. Carb reinstalled and tractor won't fire. Have great spark, went through points and installed new wires since I was doing the other work. I crank it over for 2 or 3 seconds, pull the plugs and they are soaked with fuel. If I crank the tractor over without the plugs in it will spray a mist of air and fuel out of the cylinder. Followed all directions on rebuild kit, and previously did some carbs on other tractors and never had this problem. What am I missing or did I overlook?

 

[Rons b]

I would suggest going to the JD forum with your question

 

[jim_uny]

verify spark with in line spark tester. next verify you are getting gas. check float setting is correct. not too much or too little. then see if plugs are wet.

 

[Steve@Advance]

Sounds like it is flooding.

That can be caused by the float level set too high, float sunk, damaged needle/seat, or trash caught in the needle/seat.

It only takes a microscopic piece of trash to make one flood. Commonly it gets in while the fuel line is disconnected, then the fuel flow carries it to the needle valve. Also if the fuel tank is contaminated with rust or trash, it will find it's way to the carb.

Be sure you have a clean fuel tank, and that the fuel strainer screen is clean, in good condition , and in place.

Sometimes you can get lucky and flush out whatever is in the needle valve by turning off the fuel valve, draining the bowl, then turning the fuel on. Or, turn the fuel valve off, get it started, (which it will probably do since it has been flooding), then let it run the bowl empty.

If that doesn't work, revisit the carb, make sure everything is right, try again.

 

[RandyB(MI)]

Well, sounds like this is a "new" problem that you didn't have before. You probably changed the needle/seat as is the norm for a kit rebuild. Probably a junk China needle with that stupid knob of so called "viton" on the tip as apposed to an all steel one. I suggest either put the old one back in or get a new all steel one. They just don't seal and are inconsistant if they do. Sometimes thy are a different length than the original which could have changed your float level even if you changed nothing else with the float. "NEW" does NOT mean correct now-a-days.

 

[gab]

Could be your carb. kit is junk. I put a Tisco kit in my Super M and it dripped gas, took a magnifying glass to the seat and it wasn't machined right, like they skipped the last step. Took the parts back and got another one, that seat looked good but the needle wouldn't slide into it. Took that back and bought a Walker kit from O Riley's and that was a nice looking kit. That Tisco stuff is pure junk.

 

[55 50 Ron]

Well if the plugs are wet, it has to be getting gas into the cylinders. You mentioned "installed new wires". Is that the spark plug wires? Did you also change the HV wire from distributor cap to coil? Those new wires could very well be your problem. If they are the composition type (not solid wire) they are junk. I had trouble with hard starting on my JD 50 because of the "crappy" line from the dist to coil which was that composition stuff. Changed to solid wire (plug wires were already solid wire) and problem was solved.

 

[Cudaman74]

Thanks for all your posts so far. To answer some questions, yes I did all plug wires and the wire from cap to coil. They are solid core jd wires. Put a spark tester on both sides at the same time and have great spark. Had it running after wires and before i pulled the card. Needle and seat are good, it is a rubber tip needle that seems to give a good seal (at least I can't blow past it when I hold the float closed). Tested it with light compressed air this morning when I tore the carb back apart. Float works like it should and fuel level is proper in the bowl as fat as I know. Tank was cleaned with new gas. Found no sediment anywhere in the carb.

I did get it to fire this morning. I drained the bowl and shut off the fuel and it ran. it was a very shifty run, would not idle up and smoked my shop out in 30 seconds. I let opened up the fuel and it died. Played this game for a few minutes and had to walk away fir fresh air. I do think it is pulling too much fuel into the motor but can't figure out why

Thanks and hope for more responses.

 

[jim_uny]

if too much fuel then float position incorrect. i would double check

 

[Jo Bird]

Check the oil level, any increase is usually a sign of the needle/seat not closing properly letting fuel to run into the oil. The Vitron Tip needles form a ring around them and if not perfectly seated each time will leak causing flooding and an increase in the oil level.

 

[Cudaman74]

Jim, do you have any suggestions as to the correct float level? I went off the directions on the rebuild kit that I purchased and it matched the level that it was set at when it ran before. I did lower the float a bit to reduce gas in the bowl to see if it would help, but it didn't make a difference. What is a good rule of thumb on these duplex 2bbls?

Give me a 70's big block Mopar with a tri power and this would be easy for me.

 

[Cudaman74]

Thanks to all that posted a reply to this post. It made me rethink the basics. Sometimes a person gets caught up in life and overlooks the simplest thing. It takes 3 things to make fire....fuel, oxygen, and ignition source. I overlooked oxygen, choke was not working. It was staying closed. Removed the linkage, cap and spring. Operated it manually and it runs great. Fixing that tomorrow. Thanks all.