# Honda RT5000 stops running .



## vardyman (Jun 19, 2021)

Honda RT5000 stops running after about 3 minutes. But, will start right back up and run for another 3. When it starts fluttering the choke can be pulled out that will let it continue running briefly then dies. What is going on with it? Is this a gas problem or electrical?
I have replaced CDI unit, spark plug and Coil.

If anyone has an answer please let me know. I have been fooling with this monster for several months now trying to chase down the problem by replacing everything that seems logical.

Thanks,
Vardyman


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## FredM (Nov 18, 2015)

Welcome to the forum vardyman, the first thing you should have done was bought a spark tester so you could check the spark while the engine was running and also watched the spark as the engine died, if the spark was still working as the engine died, then you would have known to check the fuel supply, you could have a floating blockage in the tank, a cracked fuel pickup in the tank, (and allow the pump to suck air) a bad fuel filter or a crook fuel pump, even a leak in the fuel pump pulse line from the engine, even the fuel line could be be going soft and sucking in and restricting fuel flow, (but not likely with the little vacuum fuel pump) or even junk floating around in the carby fuel bowl, and even bad fuel if you use the gas and ethanol mix.

You can check these components before outlaying dollars.


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## vardyman (Jun 19, 2021)

Thanks.
I do have a spark tester and I will try your suggestion.
It has an electric fuel pump, I believe, because l took the sediment bowl off and dumped the gas. Gas did not refill the bowl until I switched on the ignition. Gas line could be a problem I will check. It has a fabric covering the line and hard to see if it is collapsing.


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## FredM (Nov 18, 2015)

I am only offering suggestions on problem areas before you spend money, the fuel hose was one and if you have removed the sediment bowl off of the fuel pump and there was no major junk in it, then we could say the fuel hose would be ok, I would assume that being Honda then you will be Honda powered!!, and most Honda engines had an oil alert sensor screwed into the crankcase and if the oil went below this, the engine would be shut down, as you get through checking the fuel side and are ready to try and run the engine again, disconnect the lead at the connector near the sensor just in case the sensor could be faulty, I am not saying it is, just another check for you to try.

Another you can try, is to remove the fuel bowl from the carby and switch on the engine to check if the electric fuel pump is pushing fuel through the float needle, have a container under to catch the fuel and let run for a minute or so to be happy with the fuel pump output.

So now we are running out of options, but there are another two to check, check the flywheel key for sheer(timing) and finally valve clearances.


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## thepumpguysc (Jan 25, 2015)

I’ve seen the OIL LEVEL safety switch do the same thing..


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## Bob Driver (Nov 1, 2017)

thepumpguysc said:


> I’ve seen the OIL LEVEL safety switch do the same thing..


It's the 3 minutes that's making me wonder..... Fuel flow problems usually show up in less than a minute. The problem I've seen with fuel flow that takes a little longer to show up (3 minutes), is the vacuum pulse line, but this machine is an electric fuel pump. Usually the fuel filter mounts in Front of the fuel pump (electric or vacuum), you might try installing a clear fuel filter between the pump and the carb. That way you could see if the pump flow drops off. A short piece of clear plastic fuel line going into the fuel pump will show air bubbles if your "sucking air" on the inlet side of the pump (loose hose clamp, or bad fuel line). Spark problems are usually when a magneto(or CDI in this case) starts to heat up. If it's really 3 minutes, an air-cooled engine is usually at full operating temperature by then

I hate those damn oil LEVEL sensors, oil PRESSURE switches I can appreciate. It's the #1 problem I see when people bring me a tiller, or go-kart, with a Harbor Freight Predator engine. They definitely don't like to run on much of an incline, either front-to-back, or side-to-side. The other down side to an oil LEVEL sensor is they'll shut an engine down if the oil starts to "foam" a little at operating temp. Oil will foam a little after it's sat in the crankcase over the winter because there can be a little water in it from condesation. Oil LEVEL sensors don't appear to like bubbles and prefer to be surrounded by a solid bath of oil. 20W50 won't foam when it gets up to operating temp and it won't hurt that engine at all. Somebody is going to say "But 20w50 will make it use more fuel"..... It's a freakin' lawn mower, what OEM publishes fuel economy numbers? I've never run FE test either, but my guess would be less than 2MPG at best, on a big V-twin, operating at full governor setting


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## vardyman (Jun 19, 2021)

I do not know an oil sensor looks like. Where will I find it.?


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## Bob Driver (Nov 1, 2017)

vardyman said:


> I do not know an oil sensor looks like. Where will I find it.?


Not sure about your 40 year old RT5000 Honda (haven't seen one since Bush II was President), but here's what they look like on a HF Predator.... Works off the ground side to kill the magneto, you just unplug it. I had two customers bring me their HF engines this week they had been sweating over all morning, in the MS heat, trying to figure out. What's a fair price to charge for unplugging this damn thing and handing a guy a bottle of Gatorade?


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## SidecarFlip (Mar 25, 2021)

Boy am I glad I've never had to rely on a lawnmower shop for repairs.....lol

Only one time, when I put a hole in the side of a case on a Honda single with 3 hours on it. Yes, it had oil in it, yes, the rod let go and yes, Honda denied warranty and yes it went to the landfill. Replaced it with a Pred and been happy ever since.

Hard to beat a hundred buck Pred.


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## vardyman (Jun 19, 2021)

I will look for it and if I am lucky I will unplug it. I have no idea where it could be.


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## SidecarFlip (Mar 25, 2021)

In the side of the case, near the bottom.


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## Bob Driver (Nov 1, 2017)

vardyman said:


> I will look for it and if I am lucky I will unplug it. I have no idea where it could be.


Here this will help.....
Honda Low Oil Level Sensor


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## SidecarFlip (Mar 25, 2021)

Like a TPMS sensor but you cannot unplug a TPMS sensor. You are stuck with the idiot light on your dash until it burns out (or you replace the sensors are reprogram the new ones). Great design, just like the low oil sensor.


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## Bob Driver (Nov 1, 2017)

That... Or you can air the tires up, check them with a calibrated gauge, and then do the "reset procedure" that is in the owners manuals you said you like to burn😎


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## Scotthondubota (Sep 15, 2021)

vardyman said:


> Honda RT5000 stops running after about 3 minutes. But, will start right back up and run for another 3. When it starts fluttering the choke can be pulled out that will let it continue running briefly then dies. What is going on with it? Is this a gas problem or electrical?
> I have replaced CDI unit, spark plug and Coil.
> 
> If anyone has an answer please let me know. I have been fooling with this monster for several months now trying to chase down the problem by replacing everything that seems logical.
> ...


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## Scotthondubota (Sep 15, 2021)

I had the same exact problem and all it took to fix it was the fuel filter that is INSIDE the gas tank. It was a pain to get out but when I did just blew it out with air compressor and problem fixed. pull the hose off the bottom of the tank and work loose the filter and pull it straight down and out.


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## SidecarFlip (Mar 25, 2021)

Bob Driver said:


> That... Or you can air the tires up, check them with a calibrated gauge, and then do the "reset procedure" that is in the owners manuals you said you like to burn😎


All well and good until the button cell battery fails and then you have to replace the sensor.


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