My Tractor Forum banner

LA145 Head Scratcher

3581 Views 31 Replies 12 Participants Last post by  midwesties
I have an LA 145 that is driving me crazy and I'm hoping someone can point me in the right direction.
Here is the problem. I got this tractor which had been sitting a while and I got it basically from an estate sale. The engine has 48 hrs and everything is in great shape. Before I got it the son of the previous owner tried to get it to run but got no where starting it. I cleaned up the carb and was able to get it to run a bit by priming it running gas down the intake however it was obvious the o-rings where dried out. Rather than just buy the o-rings I opted to buy a new carb (just a few dollars more. It now runs good (maybe a sputter here and there) but the only way to start it is to pour gas in the intake. Once I've done that it runs and I can restart it. Once it sits over night I have to prime it again.
So in the interest of saving time: I've checked the gas lines, changed the fuel filter, even tried an electric fuel pump.
There is gas in the float, but it won't start. I admit I don't have much experience with these Briggs 2 cylinders and these carbs are new to me.
Any suggestions, things maybe I missed?
See less See more
1 - 20 of 32 Posts
The choke plate is most likely not fully closing.
Fresh gas?
I've suspected the choke as someone told me that these engines won't start without being fully choke. So I've held it closed as much as I could and it doesn't seem to want to close any more than it already is closed. In any case holding it closed made no difference. Am I missing something?

Gas is good.
Thanks though.
See less See more
I would suggest literally looking at the choke plate itself, that it's fully closed, even trying to push directly on the choke plate itself to see if it goes any further.

The choke on my Kohler CV22 won't close all the way in the winter, some ice seems to form just in the right place all the time, and it holds the choke open just a little bit, enough to prevent it from starting, and I have to directly rotate the choke shaft to get it closed all the way (there's a spin-mechanism when using the remote choke lever, and permits this to happen).
See less See more
I have manually held the choke as tight as possible and that seems to make no difference.
This thing is really driving me nuts.
Anyone have any other ideas?
Is there a vacuum leak after the carb (carb to manifold, or manifold to head [if present]), or some vacuum tube isn't connected. The idea being, when starting, the engine can't generate enough vacuum for the carb to function properly, but once running, it can overcome the vacuum leak and continue running.
See less See more
I was thinking the same thing just not sure where or how. I don't know if you have worked on one of these... They are a bit peculiar. I'm thinking of trying duct tape around the gasket surfaces and see if maybe that identifies a leak.
Thanks again.
Maybe try, with the engine running, and with the intake to the carb shielded to prevent the spray from going in there, spray something like engine starter spray (just a little, don't want to overdo it) around those two areas. If there's a leak, the engine will speed up.

Alternately, you can use a spray that would make the engine run worse (as this tends to be safer), but offhand I can't think of a good product to use...
See less See more
You say it runs good except maybe a sputter here and there. What I hear with that statement is that it runs .... not quite right? How fast can you back off the choke after you start it? If you need to back off the choke really slow, it would support the idea that you are running lean (either not enough gas (carb) or too much air (vacuum leak))

I would certainly spray for vacuum leaks (any change up/down in RPM while spraying indicates a leak).

Did you get the exact same replacement carb as the original. If so, it might be worth taking the jets out of the original, cleaning them really well, and installing them in the new carb.
See less See more
Is there an electrical connection to the carb for a fuel cutoff solenoid? If so, any chance that solenoid isn't opening until the engine starts (it starts from the fuel you dumped in)? If you have that, I think you should be able to pull the connector off, place a voltmeter on it, and turn the key on (maybe crank the engine) to see if you get voltage.

I don't have anything new enough to have a fuel cutoff solenoid, but when I tried to google your carb, some pics showed one.
See less See more
Dave r I'm getting rusty. That's the ticket... I'll try that and see if one of the gaskets are leaking.
Cantkeepup, its a funky carb. It is certainly like a CV, so there isn't any real control over the choke that I can find. It opens on its own.
I've definitely ruled out the fuel solenoid, I even went as far as switching them between the two carbs and eliminating it.
I'm leaning toward a vacuum leak at this point. But please keep throwing the ideas. I'm running out of them.
See less See more
You might take a look at some of these manuals to perhaps find a solution:
I'm having the exact same problem and it happened all of the sudden. I replaced the plugs, fuel pump, carburetor, fuel filter, and still the same problem. It will only start and run when primed. I checked the pump, getting plenty of gas.
I still haven't figured this one out. Fortunately I'm tractor rich so I haven't been in a big hurry. However I want to solve this so I can sell it soon while everyone is buying. The next thing I was going to try is to put Teflon string (used to pack faucets) on the gasket and see if that solves it. I'll keep you posted and please let me know if you solve it.
See less See more
I also checked my plugs (new) to verify gap, and verified spark. The solenoid on the carb (new) is getting 13 volts. The new carb has new gaskets, still nothing unless I prime the carb. It truly is a mystery.
I'll give you the rundown on everything I've tried so far.
New carburator
Checked solenoid
Eliminated solenoid
Checked plugs
Checked spark
Checked fuel pump (tried substituting electric)
Checked choke
Changed gas line

Nothing has had any effect.
See less See more
Can you remove air filer and get your hand or rag over the intake inlet to block it off when cranking?
See if it starts that way.
1 - 20 of 32 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.