Boxxer 421 will not run for more than a few minutes | TruckMount Forums #1 Carpet Cleaning Forums

Boxxer 421 will not run for more than a few minutes

Bexiesbruv

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Oil is good
Tank is not full and the cut off float switch is free
Its getting fuel
Starting is often difficult but once running it never misses a beat, until today.
Could it be the air filter? Its pretty dirty.
 

Spazznout

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When was the last oil change?
spark plugs?
air filter?
fuel filter?

That is where I would start.
 

Bexiesbruv

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Plugs, oil changed two weeks ago
Air filter, never, I have 1800 hours on it. I clean the Air filter and re oil it every oil change.
I run two fuel filters and changed the one closer to the tank about 3 months ago. Thats likely the issue, many thanks.
I will keep you posted.
 

Bexiesbruv

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It probably is the fuel filter because its running on reduced rpm but when you wind it up to maximum it shuts down after a couple of minutes, or less.
 

Bexiesbruv

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I have the truck back now. Took off one of the fuel filters, closest to the tank and ran the TM for about 10-15 minutes then it shut down.
I can hear the fuel pump running.
Would it shut down if the plugs were bad? Right up to it shutting down it runs as it is expected to.
 

the rugman

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Change the air filter - prob not it but thats a lot of hours.
 

Bexiesbruv

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Change the air filter - prob not it but thats a lot of hours.
Just been out to get the parts. Only thing stocked is the oil filter, the rest is days away. Largest Ag and small engine stockist in the area. And I am trying to replace the roof on the house as well. And its going to rain on Thursday.

So the Ag folks think its likely the ignition system getting hot then failing.
 

seagrtj

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You can check the ignition modules. Put a inline spark plug checker on each plug and see if they are getting good consistent spark. If you change one ignition module, replace both.

Here this will surely fix your problem...
http://www.jondon.com/ea-engine-21hp-vanguard.html
 

seagrtj

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well to replace the ig modules you need to pull the front pulley off and remove the shroud. The ig modules are mounted at the top of the flywheel. But to check them you can just use an inline spark checker on the spark plug
 

Bexiesbruv

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I'm not going to mess with it. I am booking it into the shop.
Thanks everyone
 

Paul Selby

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I'm not going to mess with it. I am booking it into the shop.
Thanks everyone
Just because the fuel pump is running, doesn't mean it's pumping. I had the exact same symptoms on mine and it turned out to be the fuel pump. It would pump just enough to fill the bowl in the carb and then stop, causing the engine to die once the bowl was emptied. Idling it up would of course kill it quicker.



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Bexiesbruv

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Just because the fuel pump is running, doesn't mean it's pumping. I had the exact same symptoms on mine and it turned out to be the fuel pump. It would pump just enough to fill the bowl in the carb and then stop, causing the engine to die once the bowl was emptied. Idling it up would of course kill it quicker.



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It ran tonight for 35 minutes in my yard this evening before it quit. I ran it with the air filter off, so I know thats not the issue. I feel it would quit sooner if it was the pump.
 

Ken Kaplan

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This happened to my legend. The problem was a solenoid. I will need to look at my receipt to get the exact name.


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bob_rugratz

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Just been out to get the parts. Only thing stocked is the oil filter, the rest is days away. Largest Ag and small engine stockist in the area. And I am trying to replace the roof on the house as well. And its going to rain on Thursday.

So the Ag folks think its likely the ignition system getting hot then failing.
If thats a briggs then yes change air filter. But this will cause it to run rough and possibly smoke as well.
I was thinking fuel filter at first. if you have two change both. I use clear so I can see if fuel is in it.
If its ignition system. I can tell you I had to replace my ignition module years ago on my onan engine. It would do the same thing. Run about ten minutes and quit. The guy hooked meter to engine and spun the shaft with his hand a bit. and he was like ignition module. 2 minutes cost me $95 labor but it saved my ass cause I was stumped. Also had to drive 90 miles to nearest onan dealer.
If you know how you could check your fuel bowl on carb when it shuts down. maybe needle is dirty. be careful not to drop needle off float cause it just hangs on it I believe.
also their could be a box connected to your coils. SAM box or this could be actually made into the coil assembly as newer ones are. this will cause funny starting and running issues.

igniton switch would most likely just cause it never to start ,but funnier things have happened.

One thing you could do is start engine , rev it up and pull each plug one at a time. if one of them doesn't affect the motor at all then you have a problem on that side.

So no power issues will cleaning? or putting load on engine?

If this stumps you to much I would let a small engine shop trouble shoot it for you at least. They will charge you an hour labor but it will be worth it. Buy the part from them if you can. Or just let them do the whole thing. if it turns out to be electronic you may be replacing parts you don't need to before you find the culprit. And usually they wont take electronic parts back.
 

wandwizard

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Plugs, oil changed two weeks ago
Air filter, never, I have 1800 hours on it. I clean the Air filter and re oil it every oil change.
I run two fuel filters and changed the one closer to the tank about 3 months ago. Thats likely the issue, many thanks.
I will keep you posted.
You really should change that air filter out more often. I don't change mine as often as the manual says, but those are not tap and clean filters. I found out from my first truck mount the value of keeping a REALLY CLEAN air filter. It can cause problems you wouldn't even imagine or think possible. You say, what kind of problems are you talking about? How about a fire just for example. Yes I said a FIRE!!! How about a really rough running engine blowing black smoke out the exhaust. 1800 hours is wayyyyyyyyyyyyyyyyyyyyy too long for an air filter change.

You really don't need to run two fuel filters on that thing either. I never have and that's never caused me an issue. This is the only type I've ever used and never a problem caused by it. http://www.jondon.com/ea-filter1-4fuel.html
 

Bexiesbruv

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If thats a briggs then yes change air filter. But this will cause it to run rough and possibly smoke as well.
I was thinking fuel filter at first. if you have two change both. I use clear so I can see if fuel is in it.
If its ignition system. I can tell you I had to replace my ignition module years ago on my onan engine. It would do the same thing. Run about ten minutes and quit. The guy hooked meter to engine and spun the shaft with his hand a bit. and he was like ignition module. 2 minutes cost me $95 labor but it saved my ass cause I was stumped. Also had to drive 90 miles to nearest onan dealer.
If you know how you could check your fuel bowl on carb when it shuts down. maybe needle is dirty. be careful not to drop needle off float cause it just hangs on it I believe.
also their could be a box connected to your coils. SAM box or this could be actually made into the coil assembly as newer ones are. this will cause funny starting and running issues.

igniton switch would most likely just cause it never to start ,but funnier things have happened.

One thing you could do is start engine , rev it up and pull each plug one at a time. if one of them doesn't affect the motor at all then you have a problem on that side.

So no power issues will cleaning? or putting load on engine?
.

If this stumps you to much I would let a small engine shop trouble shoot it for you at least. They will charge you an hour labor but it will be worth it. Buy the part from them if you can. Or just let them do the whole thing. if it turns out to be electronic you may be replacing parts you don't need to before you find the culprit. And usually they wont take electronic parts back.
No power issues at all.
Guy at the shop I spoke to got on the phone to B & S last night. They figure its overheating. If it were ignition modules it would run rough. Its going in the sjop at 8.30 this AM

You really should change that air filter out more often. I don't change mine as often as the manual says, but those are not tap and clean filters. I found out from my first truck mount the value of keeping a REALLY CLEAN air filter. It can cause problems you wouldn't even imagine or think possible. You say, what kind of problems are you talking about? How about a fire just for example. Yes I said a FIRE!!! How about a really rough running engine blowing black smoke out the exhaust. 1800 hours is wayyyyyyyyyyyyyyyyyyyyy too long for an air filter change.

You really don't need to run two fuel filters on that thing either. I never have and that's never caused me an issue. This is the only type I've ever used and never a problem caused by it. http://www.jondon.com/ea-filter1-4fuel.html
I ran it with the air filter off last might and it still quit after 40 minutes, but I will be changing it anyway, thanks. I use the same filter you linked.