boxxer 421 w/ briggs and stratton dies

I see your new to the forum, welcome to TMF. where are you from?

whens the last time u changed spark plugs? check fuel filter, maybe clean carbs. im not familiar with the boxer, but have used briggs & stratton machines. take it to a small engine repair shop or a lawn mower shop, these guys work on these type of motors all day and charge far less than your local distributor.

hope i help in some way. Good luck .







www.carpettechnologies.net

The first thing I would check is your high and low pressure orifices and make sure they are clean. If either gets clogged the machine can't cool itself down and when it gets over heated it will shut down to prevent further damage. Remove both the plugs on the front of the machine and turn the machine on then turn the pump on for just a few seconds to flush them out. Then check the orifices for any possible clogs and make sure your filter screens are clean and put them back in. In some cases it is necessary to remove the orifices, but I have never had to do that in over 8 years. This is the most common cause of overheating related shut downs with the Boxxer 421 I think. You should also do a descale immediately if you haven't already done that. Plugged orifices, especially the tiny high pressure one, could very well be the problem and won't cost a dime to fix. If you continue to experience problems after checking the orifices and descaling you could have a plugged up vacuum heat exchanger. This is from build up on the outside of the heat exchanger that comes off the vacuum exhaust so it has to be removed and cleaned to fix it. If your machine is getting to have a lot of hours on it like over 1500 that is a very real possibility. That exchanger will cause back pressure on the engine and it will shut down. This will cost at least a few hundred bucks to get serviced at least that's what I paid at Jondon. How many hours are on your machine now?

Here is some trouble shooting help from Hydramaster that may be of help.

1.0. Machine overheats and shuts down
1.1. One or both orifices or filter screens are restricted. Remove and inspect.
Clean as necessary. Note: Make sure orifices are not interchanged.
1.2. High pressure dump solenoid is restricted. Inspect solenoid and the hose that
delivers water to it. Clean or replace as necessary.
1.3. Diverter valve is stuck or out of adjustment. Operate diverter valve manually
(make sure exhaust system is cool) to determine if the movement of the valve is
restricted. Repair or adjust as necessary.
1.4. Diverter valve and high-pressure dump solenoid are not functioning. Check
the fuses that provides power to the diverter mode relay and to the temperature
controller.
1.4.1. If a fuse is blown, inspect electrical system for worn and shorted wires. Repair or
replace as necessary.
1.4.2. If fuse is good, inspect diverter relay and diverter switch. If either is faulty,
replace.
1.4.3. If switch and relay are good, refer to qualified service technician to test
temperature controller and RTD sensor.

http://www.hydramaster.com/Portals/0/Manuals/man182-065.pdf

If after going through those trouble shooting steps as best you can I would get your machine in for service ASAP if the problem is not resolved. The blower heat exchanger being plugged up can cause a very similar if not exactly what you are experiencing. I hope it's just the orifices being plugged. Good luck. Btw, the fact that this issue occurs after the machine is heated up tells me that it is probably not engine related which is good news for you, but if you let it go it could very well do damage to your engine. The machine is shutting the engine down.

The orriffes are clogged. Do't mix them they are diffrent sizes. Descale first.