# Briggs Intek runs rough, possibly in a flood?



## Country Boy (Mar 18, 2010)

I have a "Murray" tractor at work that has been giving me fits. Its actually built by MTD under license from Briggs and Stratton who owns the Murray trademark now. Anyway, it came in because the customer had hit something and bent one of the blades. I ordered a blade for it and put it on tonight. When I went to fire it up, it ran like crap. It was popping and backfiring and misfiring so violently that the tractor was shaking. Putting it in Choke helped somewhat, but not much. I idled it down and it evened right out. 

I tried the following:

-Drained and refilled fuel system with fresh fuel.

-Replaced spark plug.

-Tested spark, its strong and steady.

-Checked the flywheel key in case it sheared when he bent the blade. Its in perfect shape.

-Cleaned the flywheel magnet, ignition coil and mounting bosses to insure good contact.

-Tried adjusting the needle valve on the carb (had absolutely no affect either at idle or WOT)

One thing I noticed when I was working on this unit is that the engine is very badly corroded and rusted for its age. The engine was built January 26th 2012 and the unit was built February 6, 2012. The engine looks like its many years older than that. The flywheel had a thick coating of rust, the aluminum block was turning white with corrosion, and the bolts holding the sump cover on were rusty. I also noticed that the carburetor had a stain in it like water had pooled in the venturi and the bottom of the choke and throttle plate were corroded. The bowl of the carb is perfectly clean inside, as is the rest of the inside of the carb. The only thing I see is that corrosion in the throat of the carb.

Could this engine have been in a flood? How else could that much water have gotten into the intake through the filter? How could it have gotten that rusty/corroded in such a short period of time? My next question is, if it was in a flood, what else could be wrong to cause it to run so rough at more than 1/3 throttle? The problem starts suddenly and goes away just as suddenly as you bring the throttle up and down. As I was driving home tonight, I had the thought to check the exhaust to see if something was plugging it up like mud or something. I don't know what else could be causing the running issues unless something is messed up with the valves.

The owner of this unit is a disabled Veteran, so I want to get it running tip top for him, but its really kicking my butt. Any other suggestions?


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## rstarch345 (Dec 21, 2012)

Just a couple of thoughts. Did you replace the fuel filter? Are you running the engine with no load?


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## Country Boy (Mar 18, 2010)

I didn't replace the filter yet. When I drained the fuel system, fuel seemed to flow through the fuel line with no troubles, and the tank and filter were clean. The engine does this when driving the unit or just letting it run with the parking brake on. Didn't try running the mower deck yet as the blade was badly bent. I'm trying to do as much research on this as I can so I don't waste a lot of time working on the unit and driving the bill up. I may just pull the exhaust today and see if its blocked. It has a series of 90 degree bends in it that might have blocked if it was under water. Beyond that, I'm not sure how to proceed. I don't want to start tearing this thing apart if I don't need to.


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## Country Boy (Mar 18, 2010)

Little update on this unit. I ended up just putting the unit back together and sending it back with just the new blade on it. My boss dropped it off and talked to the owner and was told that they bought it at a local WalMart as a floor model. It had sat outside all summer in the rain and they got it cheap on clearance. They also bought the extended warranty on it, so my boss told them to look into the warranty because of what I had found. They seemed fine with that. I did get it running a tiny bit better by blowing air through all the carb passages, but it still didn't run all that well. When you turned the deck on, it would even out a bit. Customer is happy, so that's what matters I guess.


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## wjjones (May 28, 2010)

Well being outside in the weather explains the corrosion, and rust. The engine I bought fot the dys4500 I fixed had sat outside too, and the block had pitts from corrosion, and the same rusted spots as well.


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