Where do I begin?

Wed Jun 16, 2010 11:15 am

Well, when i purchased my loboy 154, the previous owner informed me to make sure i shut the gas off when the tractor sits or I would have starting problems. The other day I went to cut grass i opened the petcock climbed on but realized that the battery was dead. I forgot to turn the key to the off position from the last time I cut grass, which was a few days prior. I climbed off, went out and bought a new battery after i couldnt get the old one to take a charge, brought it home, put it in the tractor. The tractor still wouldnt start. I then realized that I forgot to close the fuel valve before I went to go get the new battery.

I troubleshooted this tractor for an hours. I drained the carb by taking the lower drain plug out, pulled and cleaned the spark plugs, checked the coil, cap and rotor. Im getting spark. Not a great spark, but spark none the less. Still nothing. The carb fills with gas every time I try to start the tractor.

My father mentioned that the carb should not build up with fuel when the valve is left open no matter what when the tractor is just sitting, so I purchased a carb rebuild kit and am about to take this task on. However i called a local cub dealer and that individual informed me that the problem may be much more severe. This person was talking about throttle body being bad, bent valves, etc etc. This tractor ran great before this series of events, I practically had taken the whole thing apart when i first bought it, cleaned it, fresh paint, seat etc...It looks like a million bucks, but its just sitting in the garage unable to start.

Anyone have any ideas?

Re: Where do I begin?

Wed Jun 16, 2010 11:29 am

Its just your carb thats it.

The float level is too high or your needle and seat is leaking making the gad build up in the air cleaner connection hose. Or you have dirt in the needle ans seat area too. Your float level may need adjustment or your carb needs rebuilding too or a good cleaning might do it too. The float level can be finiky at times too on where we set it so it won't leak or over fill the bowel. Sometimes it takes two or three times to get it exactly right but it depends on how much the PO bent the float is what i'm getting at. BB

I purchase most of my carb stuff at; http://www.mcdonaldcarb.com/ or at TM tractor parts here at our site. McDonald has carb and ign stuff for most tractors.

BTW; I do notice if we run the fuel level low in the tank or run it out of gas it can send dirt and crud into the fuel line too which leads to the carb. My neighbor does this all the time and now i'm married to his tractors once i fixed them. Meaning he calls me all the time. Heck sometimes he's just out of gas. He is old but we do laugh at it.

Re: Where do I begin?

Wed Jun 16, 2010 11:33 am

If you have points and a distributer, you should check them for being burnt. Leaving ignition on burns the points and makes starting really bad.

Re: Where do I begin?

Wed Jun 16, 2010 11:39 am

Thank you gentlemen, I already took the carb off and wiped the outside of it down the other night. I recieved the rebuild kit in the mail yesterday and I think tonight im going to carefully start to take the carb apart and check it out. I pray that this works or the tractor may be up on this site for sale soon. I'll keep you posted.

Re: Where do I begin?

Wed Jun 16, 2010 4:24 pm

You may also have fried the coil and condenser so might as well figure on replacing them and don't be in shock. Leaving switch on happens to the best. Just goes with the ownership and operation of tractors. You really do need good hot spark, if at all possible. Makes starting and running a whole lot better. thanks;sonny

Re: Where do I begin?

Wed Jun 16, 2010 9:57 pm


Well, I don't have a 154, but I have had the same problems with my 48 Cub -- they share the same engine etc.. If you leave the ignition on -- you will most likely have smoked the points and condenser. Leaving the gas cock on should not be a problem on a properly functioning carb.. however.. if you are having problems, then the carb needs a rebuild.

Tom and Lynn at TM Tractor can supply all that you need for the points, condenser although it is also available at NAPA. You can check the conversion table at CubFAQ's #1 Para 7 :idea:

Follow the links below and then the Numbered Cubs link on the server when you get there. There is some info on the 154.. probably might be helpful.

Image to the Farmallcub.com :big smile: Forum Family. And you have come to the right place for all things Cub related. If you click on the Site Rules, Regulations, & Important Information, it will point you to :arrow: the Welcome Wagon wherein you will find links to many useful sites and topics. One of which is the Cub Manual Server. Enjoy!.

Re: Where do I begin?

Thu Jun 17, 2010 5:38 am

Just because you have spark, don't assume it's good enough spark to start the engine. Weak spark will jump the plug gap in open air, but not in the cylinder when under the pressure of compression. Along with fixing that leaky carb, get your ignition system back in shape. As mentioned, you probably smoked the points, maybe more.

Re: Where do I begin?

Thu Jun 17, 2010 7:02 am

Thanks for the insight. I drove over to the local case dealer and picked up the last cap/rotor/condenser kit they had on the shelf. The points looked a bit green so I'll change that out along with the carb components and see what happens.

Re: Where do I begin?

Mon Jul 26, 2010 11:04 am

Update: I rebuilt the carb, changed the cap, rotor, condeser, etc. Tried to start the tractor and it was a no go. Checked for spark at the coil and it was very weak. I went to napa and bought a new 12 volt coil, installed it and the tractor fired right up.

The issue at hand now is that the tractor cuts out at about three quarter throttle. I reviewed the manual and i believe i have the idle screw as well as the throttle screw is set properly.

Re: Where do I begin?

Tue Jul 27, 2010 12:03 am

Tweek your timing just a tad!!---You may be a tad fast, or on the other hand a bit slow,If you adjust the dist. , try going both directions!--a little at a time---Also the point gap is kinda hard to set!---Can't see in there very good and not much room to work! thanks; sonny

Re: Where do I begin?

Fri Jul 30, 2010 12:15 pm

I have several tractors, including a Farmall Cub and a Cub 154, which I use infrequently. When I put them away, I shut off the gas and let them run until the gas is out of the carb (and the tractor dies), then I have a quick disconnnect on the battery and the disconnect the battery. Just part of my routine and it solves the problem of gummed up carb and dead battery from not shutting the tractor off. I always shut off the gas when even I let the tractor set over the noon hour or something. Just something I learned from my dad as a kid. Maybe not necessary but does not hurt (and might help).


Re: Where do I begin?

Fri Sep 17, 2010 5:38 pm

Gotta love, unleaded gas and ethanol in these old machines.But seriously my outboard,tractor, or any other equipment that has down time don't run as good any more unless run dry after each use, even with stable in it!!!!!!

Re: Where do I begin?

Fri Sep 17, 2010 6:35 pm

orchardinc wrote:The issue at hand now is that the tractor cuts out at about three quarter throttle.
Agree with Sonny. First thing to do is check the ignition timing and distributor advance. Make sure the timing and advance are correct. If both are correct then move to carburetion.

orchardinc wrote:I called a local cub dealer and that individual informed me that the problem may be much more severe. This person was talking about throttle body being bad, bent valves, etc etc.
Must have been a youngster.

Re: Where do I begin?

Sun Jun 03, 2012 7:43 am

I just wanted to say thanks to those that provided some insight into this issue. Its been a long year and a half around here but I finally got the 154 running like a top again. The fuel and electrical system are in A1 shape.

Question. Due to the tractor sitting in the garage for a while, it seems it has developed a leak in the rear seal. Im getting some oil running down the oil pan from the back end of the engine. Does anyone have a link they can share of how to address this? Thanks in advance.


Re: Where do I begin?

Tue Jun 05, 2012 6:37 am

Phil Lenke (on this forum) rebuilds these rear seals. Price is reasonable and is the best solution.
You ship your rear cover to him with a check and he sends it back straight, machined, and with a seal in it ready to go.