# MTD Yard Machine HELP !!!



## tstimac64

Hello Everyone.

I have a 2002 MTD Yard Machine 42" with a Briggs & Stratton 17 HP OHV engine. It starts up great. You run for 8-10 minutes and it looses power then stalls. I let it set for about 15 minutes and it will restart and run for another 8-10 minutes. Sometimes a little less on the restart. I suspect a coil ? Am I on the right track with this assumption ? I just don't want to throw parts at it. Any help will be greatly appreciated.


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## jhngardner367

Make a clamp, to hold the plug wire 1/4" from the plug. Start the engine,and watch the spark(best when done in dim light).It should stay strong,and blue. If it looks weak,or turns weak/yellow, and dies, you have a coil going bad. 
make sure the clamp doesn't ground the spark.An old spring - type clothes pin works well.
If the spark stays strong,and blue,and the engine dies,it could be a bad switch,or even a fuel solenoid shutting off.


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## dangeroustoys56

I had a weird situation with my 90 murray - similar to yours - cept it just wouldnt start at all. I went thru the ritual: cleaned the carb, cleaned the flywheel contacts, regapped the magneto ( after cleaning off the ends) - even unhooked the mag kill wire - still would crank, but no start.

It defintely had gas, so i checked for spark- was bright and blue and shocked like crazy, changed the plug also. Couldnt figure it out. So i dug thru my parts bin and found a good used magneto, mounted it all up, turned the key and fired right off . Only thing i can think was it wasnt hot enough of a spark to fire it up.

As Jhngardner suggested - it could be the antifire solenoid acting up as well - ive had issues with that on my 2003 murray - i bypassed it with a manual fuel shutoff valve.


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## Mickey

From the description, I'd not overlook the possibility of a nearly blocked gas cap vent. A lot would depend upon how much cranking necessary for the restart. Along similar lines, I'd take a look for the possibility of collapsed fuel line as well. If restart is almost immediately, then has to be related to some thermal issue like the coil as has been mentioned.


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## jhngardner367

Good catch,Mickey! I never gave the gas cap/fuel line a thought!


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## TruckNSeaBee

Check vent in gas cap . or is something kinked in gas line? Is float in carberator sticking partialy closed where as it allows gas to slip through when tractor sits not running allowing float bowl to fill up while sitting not running but then when its ran it does not allow gas supply to keep up with demand because it is partially plugged stuck? {tap bowl with screwdriver handle lightly to try to unstick}

Do you have something metal that is rubbing against one of youre kill swithches like a no rider on seat kill button switch shorted out by something or the reverse while blades are turning kill button switch shorting out the switches in turn killing engine or a wire shorting out because it is loose Engine ground connection tight?Battery connections tight???
Or CHECK THE BOLTS THAT HOLD YOURE COIL IN PLACE THEY COULD HAVE BECOME LOOSE IF THEY ARE THAT WOULD MAKE WRONG AIR GAP MEASURE MENT FOR SPARK FIRING MAKING WRONG INDUCTIVE SPARK CHECK THIS BEFORE BUYING NEW COIL CHECK THE COIL MOUNTING BOLTS IF LOOSE GET CORRECT AIR GAP BY LINEING UP COIL WITH MAGNETS ON FLYWHEEL AND RETIGHTEN PUT SOME MILD LOCKTIGHT ON BOLTS}AND IF THAT WAS NOT THE CASE CHECK GO BUY OR if you have a good known coil try a known good coil sometimes the coils can go bad and get heated up and not work when hot because the connections inside expands while hot causing it not to work no spark .


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## tstimac64

Hello Everyone.

My 2002 MTD Yard Machine 42" with a Briggs & Stratton 17 HP OHV engine that would only run for 8-10 minutes. I have replaced the gas cap. Checked the coil and it is fine. I am about ready to throw my hands up and give up. The great people on this website have been the only help I could find. Now I have been told ( Possible Head Gasket ) . Is this possible ? I removed the top engine cover. I do not see the headgasket pushed out. I do not hear any type of compression leak. I am going to purchase a compression tester today. Any suggestions ?


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## Bill Kapaun

Did you check the coil IMMEDIATELY after it stalled and compare the quality of the spark to what you get with a COLD engine?

Simply loosening the gas cap will let you know if you have a vent problem. (Maybe you got another bad cap?)

A restricted fuel filter "could" give identical symptoms. Engine uses fuel slightly faster than it can flow into the carb bowl. Carb runs out of gas. Engine sits and the bowl refills. Repeat....

What's a compression tester going to do for you? If it didn't have compression, you won't get it started in the first place.


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## jhngardner367

I doubt if it's a head gasket. It would smoke really bad if it were,as the OHV engines usually blow them at the pushrod passage area. I would follow Bill's advice,and check it the minute it dies,and,if the spark is good,check the fuel system.


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## tstimac64

*My 2002 MTD Yard Machine 42" with a Briggs & Stratton 17 HP OHV engine that would onl*

I think I will replace the fuel filter then. I did replace the fuel line because it was very soft and figured it may be collapsing inside, but I did not replace the fuel filter. If that does not work, I will replace the coil. It was hard to see if the fire was weak in the sunlight. Checked compression last night after it quit running and it was good and did not leak down. Thanks to everyone for your suggestions.


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## Bill Kapaun

tstimac64 said:


> ... I will replace the coil. It was hard to see if the fire was weak in the sunlight...


There ARE other times of the day to check it.


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