LoBoy 154's

Fri Aug 20, 2010 12:38 pm

I inherited two LoBoy 154 tractors from my father a few years back. The older is a 1968 and the newer one is a 1973 with the creeper gear. Neither have 3-point hitches. The '68 is getting towards the end of it's life it appears but that is another topic.

My question concerns the '73. My problem that has been going on for awhile now is that the tractor will run for a couple of hours and then it will shut down and will not restart until the tractor sits for several hours.

When it has not been in use for a week or so she will start right up. When having been in use mowing grass it will run fine for a couple of hours and then once it bogs down in some heavier grass it will slow down, start to sputter, and eventually die out completely. It will not start again until after it sits, sometimes for an hour or more.

We have changed the air filter, changed the oil, put in new plugs, drained and cleaned the fuel bowl below the gas tank, and even put a new coil on her but the problem still exists. I am looking for some advice and where to start to look to try to correct the problem. I have been told that most likely it is a vapor lock. If this is the problem what do I do to correct the problem. I have some mechanical ability but I am by no means a mechanic.

If anyone has dealt with this problem would appreciate some advice and suggestions.

Re: LoBoy 154's

Fri Aug 20, 2010 2:36 pm

Since you have already replaced the coil, I would replace the points and condensor. Coils are not immune from being bad out of the box, however.

Re: LoBoy 154's

Fri Aug 20, 2010 4:34 pm

To help narrow it down, next time it quits put a spark tester on it to check for spark.

Re: LoBoy 154's

Fri Aug 20, 2010 9:26 pm

I don't have a lot of manuals on the Numbered Series Lo-Boys, but I do have some stuff on them though - Cub 154 Lo-Boy, and the Owner's Manual and Part's Catalog are available. The I&T IH-38 1974 Edition Complete can be of help diagnosing many problems.

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It certainly sounds like a coil issue and as Don said, bad ones out of the box are not unusual. I would also be replacing the condenser and the points as well.

Re: LoBoy 154's

Tue Aug 24, 2010 10:49 am

Condensor???

Next time it shuts down check the spark, if the spark is ok then checkout the fuel bowel and the gas tank. Mine did the samething when i got it and there was something plugging the gas flow above the fuel bowel. It would stall and restart when the fuel bowel filled up but it got worse as i ran it. Then it finally stalled and failed to restart so i took it apart on the lawn were it was stuck and fixed it.

I tell my son not too mess with it when its running ok because you thyink the newer part is better than the old part but most new parts or my luck is i get the bad one even if its 1 out of a million i get than 1 bad one. He wanted to change his electric fuel pump on his truck thats running great.

Re: LoBoy 154's

Tue Aug 24, 2010 11:35 am

Before replacing everything, you may want to check for spark when it quits and if there is spark then spray some starter fluid into the carb. If it fires then remove the main jet and check for fuel flow. Vapor lock, plugged filler cap, plugged sediment bowl all can cause the symptoms


If there is no spark then pull off the distributer cap and with the points open, short the points with a screwdriver, good spark out of the coil will eliminate the coil and condensor as the problem.