Carb rebuild? Distributor cap?

[cody96ss]

Proud owner of a 77 Lo-Boy. Carb drips gas whenever not running. It will only run for a few seconds then dies. Also, I had to turn the distributor cap clockwise until #1 is almost at the bottom to get it to fire at all... So, I’m asking if I need to rebuild he carb, which kit is best? Zenith comes up a lot when I’m searching, will that do the trick? And where is everyone else’s cap turned to? What is the location of the ‘1’ when your tractor is running? Got a good deal on the tractor so I don’t have a lot invested...

[Bob McCarty]

A dripping carb usually means that the needle valve isn't sealing. That can be caused by debris/corrosion in the valve seat, or a problem with the float. Your LoBoy should have a Zenith carb unless someone replaced it with an earlier IH carb. You probably don't need an entire kit. The "1" refers to one o'clock, so the rotor should be pointed to the upper right. The timing of your tractor is off and could be caused by several things. With a second post, you'll have access to the forum manuals which are found under Quick Links (upper left) and then PDF manuals. And welcome to the Forum. Do you have any history on the tractor?

[cody96ss]

Oh wow, with ‘1’ at one o’clock it wasn’t doing well starting. With it at about five o’clock it runs for a few seconds before sputtering out. I know absolutely nothing about the history, was purchased from an auction. It has been “tinkered with” to say the least. Block is orange, most bolts have paint chipped off of them and edges slightly knurled. Several parts have paint falling off of them when parts near them don’t, so no doubt some parts swapping.

So with the carb, is that something I can just try and sand out with some 2000 grit or a 3m pad?

[Bob McCarty]

Click on "quick Links" upper left, then on "Farmall Cub", then on "Service Manuals", then on "IH service 2-fuel-governor". Scroll down to 2-9 and below for directions and an exploded view of the Zenith. Carb cleaner should be adequate unless there are deposits or corrosion in the needle valve cage/seat.

[Glen]

Hi,
You didn't say which model number of LoBoy it is.
They recommend on here reading the owner's manual, they have lots of info. They are in the manual section at the top of the page.

The needle and seat can be wornout from use also, and need replacing.
Below is a listing at TM Tractor for them.

http://www.tmtractor.com/new/fl/107fp.htm

The float level needs setting correctly, to the right level, so it will work right.

Below is their carburetor page, there are Zenith parts in the 6th row down the page.

http://www.tmtractor.com/new/fl/fl_001newparts.htm

[seahaul]

I'm sure Bob McCarty has a lot more experience than I do, but I always thought the "1" mark on the distributor cap indicated the no. 1 cylinder wire location. With the no. 1 cylinder piston at top dead center on compression stroke, the rotor should be pointing at the "1" position on the distributor cap. Usually this is about the 5 o'clock position.
Charlie

[Bob McCarty]

I'm sure Bob McCarty has a lot more experience than I do, but I always thought the "1" mark on the distributor cap indicated the no. 1 cylinder wire location. With the no. 1 cylinder piston at top dead center on compression stroke, the rotor should be pointing at the "1" position on the distributor cap. Usually this is about the 5 o'clock position.
Charlie

Charlie, You're right except for the first half of your first sentence. Not sure what I was thinking when I typed that.

[ibdilbert]

I just rebuilt the carb on my 185, was fairly easy even for me. Took maybe an hour, and I wasn't really trying to break a record. The kit came from HamiltonBobs.

https://hamiltonbobs.com/cart/product/z ... lo-boy-mm6

[cody96ss]

It’s a 184... sorry I thought the year covered that. I assumed the ‘1’ on the cap was for cylinder 1 and have the cap set up that way. Glad to hear the 5 o’clock is close. I have the next two days off and can expect to spend some time with the carb. Thanks fellas for the help, I’ll pull up these manuals and see what the inside of the carb looks like. I’ll update with any info or questions!

[Larry B]

If the dist is setup the way the manual wants it when the no.1 cylinder is at TDC on the compression stroke the rotor should be pointing to the 1:00 position. The distributor can be "clocked" to any position depending on where the rotor is positioned when the distributor is installed. Whoever installed the distributor clocked the no.1 plug at 5:00.

[cody96ss]

Alright boys I'm out here with the tractor. Can't decide if I want to just start off by cleaning the carb

or if I want to try to start it and find the sweet spot for the distributor.

The circle labeled '1' is where the '1' on the cap is currently located. Logic tells me to pull the carb off and clean it so I can eliminate one problem, but I want the gratification of hearing this baby Purr!!!

[Larry B]

Don't worry about about the distributor position. My 184 has the #1 plug at the same position as yours at about 3:00 all it means is the distributor is installed one or two teeth off. Just make sure your timing is correct and the centrifugal advance works. It will run just fine the way it is.

[cody96ss]

1558047424335.jpg

Don't worry about about the distributor position. My 184 has the #1 plug at the same position as yours at about 3:00 all it means is the distributor is installed one or two teeth off. Just make sure your timing is correct and the centrifugal advance works. It will run just fine the way it is.

EXCEPT IT WON'T! Lol... Ok, I've tested the coil, wires, replaced plugs, cleaned carb and fuel tank, fresh 93 octane, and even gave the old girl a spritz of starting fluid. Won't go for more than about 2 second. It fires long enough to disengage the starter, then sh*ts itself. How much spark should I have? Should I hear a CRACK like my 78 Nova? I can see the spark in the daylight, but seems weak to me - but I'm a car guy. Also, not sure if I'm getting fuel...any easy way to tell?

Ugh, I feel like an idiot... I'M A MECHANIC! I just don't have deep pockets, and don't want to chance breaking bolts or anything by ripping stuff off...

[Larry B]

Ok. Here is my checkout for the ignition system. Some of this may seem obvious but it check most things.

Remove the distributor cap and bump engine till points are closed.
Connect a plug wire from the coil tower and other end to a spark checker or hold it 1/4" from ground.
With key on manually open the points and check for spark. If you can get 1/4" spark in air you have enough spark to run the engine. If won't jump 1/4" gap check point resistance, battery voltage at + terminal of coil, bad condenser, bad coil.
Assuming you have good spark. Position engine with #1 cylinder at TDC on the compression stroke. Remove the distributor cap and loosen both distributor hold down bolts. Turn on the key. Rotate the distributor slightly clockwise till the points are closed. Connect a plug wire to the tower of the ignition coil and other end to a spark plug and ground the shell of the plug. Slowly rotate the distributor counterclockwise till the points open and the plug sparks. Tighten the distributor hold down bolts. The engine is now static timed at TDC. Whatever tower on the cap the rotor points to will be #1. Install cap and wires. Double check firing order 1-3-4-2 distributor turns clockwise. Point gap .020. Install a NEW set of Champion D18Y plugs with .025 gap.
This will start and run the tractor. Still need to check with a timing light and the advance.
Give it a shot of starting fluid and try to start. Should run for a couple seconds.

[cody96ss]

Spark is good for 1/4"... Sparks every time I open the points. With the naked eye, it appears as though the point gap is way larger than that...
I've never seen heads like this. Can't see the piston through the spark plug hole. Just see a piece of cast steel... How do I tell when #1 is at TDC on the compression stroke? I really appreciate your time