Marvel Schebler 905TSX Carb problem

[Anonymous-0]

I have posted this in the Deere John section a couple times but still have not been able to get the answer I need.

Short version: I recently got a 2020 JD been setting for years, wouldn't run. PLugs, points, cap, rotor - it started but wouldn't accelerate. Pulled fuel screen in side of carb, plugged with rust. Drained gas tank, cleaned out carb with carb cleaner (barnyard repair, you understand) put new screen and gaskets in carb. It started, ran good and got almost home before it died and would not accelerate again.

Drained tank, cleaned out rust good, coated it with Red Kote. Blew out fuel lines, cleaned carb and screen again. Still won't accelerate unless you EAAAASE it up slowly.

Lots of black smoke coming out the stack.

Cleaned and lightly lubed the centrifugal weights in distributor, checked points, plugs, etc. again.

The carb has disconnected fuel cutoff solenoid. I understand they were mostly problematic and most guys took them off (Especially since they're almost $200 to replace).

I tried to buy a rebuilt carb from YT and they are out. But the picture of that carb shows what looks to be an adjustable jet in the place where my solenoid is.

Where do I get such a part (YT says they don't have them)? How do I adjust the carb (where exactly is the main jet)?

Thanks for your help, I'm not a carburetor jockey, obviously.

 

[Bob]

Typically, the main jet adjustment is part of the electric fuel shutoff solenoid. What's there now, a simple plug? A similar carb I worked on recently had a adjustment needle valve assembly installed where the solenoid should have been. That would be the RIGHT thing to do, if you feel it's necessary to remove the solenoid.

It APPEARS Deere part #RE19406, @ about $12.00 is a the manual adjustment screw assembly to replace the $185.00 solenoid.

Also, there may be something wrong in the venturi area, or little passages in the bottom 1/2 of the carb, leading up to the idle circuit up in the top. There are several passages that lead into the area where the throttle plate closes against the bore that may be clogged, adding to the "will not accelerate" problem. (Idle transfer passages.)

 

[Anonymous-0]

Try Bob's number with JD for the manual needle or call V E Petersen in Ohio largest Zenith MS dealer for it 800-537-6212. Use small wire and small drills to clean out all jets and passageways by hand and remove all jets and main load jet to do so. Load jet has tiny holes in it too that have to be clean.

 

[Jerry/MT]

Most of these carbs store fuel in what"s called a "well" for acceleration. The "well"surrounds the main nozzle in the fuel bowl. There are some holes on the main nozzle that provide the additional fuel from the "well" for acceleration. When the throttle goes wide open the increase in airflow reduces the pressure in the venturi and this in sucks the additional fuel for acceleration. Make sure that your main nozzle is clean and that your initial timing and centrifugal advance are working properly. Also make sure don"t have an air leak downstream of the carb metering section that"s leaning out your mixture. It could be at the throttle shaft, at the carb connect flange to the intake manifold or at the intake manifold/cylinder head interface.

 

[chuck craig]

PLEASE what is RED KOTE Sounds like it what I need for a tank I have that needs cleaning. THANX

 

[Anonymous-0]

Thanks, guys. I got that adjustable needle valve on order through JD now. Part of my problem is that I can't get some of the brass jets out of the carb body, afraid I'll strip them out. I've soaked and blown them with 125PSI. I'll see how the new needle does - and check the timing.

Red Kote is available from O'Reilly auto parts in my area and also CarQuest carries it. It coats the rusty gas tank with a red plastic that seals the rust in. Good stuff but make sure you get all the loose rust out first. I used five pounds of deck screws, sloshing them around like a landslide kinda to scour the rust off. Also. rinse the tank out (I used gas so no chemical or moisture concerns) and let it dry real good, like a day, before putting the Red Kote in. Blow the fuel lines out too before you go back together. One more thing, when you are sloshing the Red Kote around the tank, get it all on one side, say the bottom, then flip the tank 180 degrees so the coating drips from the "top" onto the opposite surface. It is a more even distribution than you will get with sloshing alone. The stuff has the consistency of heqavy paint. Do the 180-flip on all sides of the tank to ensure complete coverage. Take you time and make sure it dries at least a day or two before reinstalling the tank. Good luck.