# 15.5 B&S MTD Yardman



## whyme (Jul 4, 2005)

hello,
i have a 1997 15.5 yardman (briggs). i was given this mower being told it needed a battery. i replaced the battery and it still would not start, so after looking over some forums i found out to check the starter by jumping to it's posative, and doing so the starter engages but it barely (most times not at all) turns the flywheel.
now for the good stuff, the other year when hurricane ivan came through we got a ton of rain from it, the guy i got the mower from lives near a creek and had a couple of feet of water in his garage where he kept this mower. that being said what kind of internal damage might i be looking at and is this worth messing with? i forgot to mention i can turn the flywheel by hand
thanks in advance


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## bugman (Aug 12, 2004)

well, the oil may be full of water if it totally covered the mower past the carb intake. the solenoid may be fried, and the battery may need a charge to turn it over, but change the oil to be sure.... or atleast check it.


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## whyme (Jul 4, 2005)

thanks for your reply,
there is a little bit of water in the oil, i removed the fill tube, and there was a small amount of water on top, so i definantly need to change that i replaced the selenoid, but had forgotten to post that above. if the water came in thru the carb, will that need a rebuild? and would you think that the cyclinder would be rusty or anything like that?


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## bugman (Aug 12, 2004)

well, if it has a cast iron bore, the rings may have stuck to the bore, but it moves freely suggesting it had maybe been run before it happened and had a good coating of oil on them maybe. or it just never stuck. but unlike steel, iron doesn't get pitted easily and it rusts very slowly. oh and the carb will most likely need to be torn apart, make sure the float is good, because water will settle in the carb bowl, rust the pin and rust the bowl. and old gas gumms up, soak it in carb cleaner and blow it out good, replace any bad parts. oh and i forgot to ask, did you check the spark plug for spark? as long as it has spark, it should fire if its getting gas as long as the flywheel keys good. which it should be... also make sure the batterys fully charged. also a inline fuse may be blown, or the key switch may have gotten messed up. also something may be grounding out somewhere, if you get no spark..... or the coils just shot.


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## whyme (Jul 4, 2005)

thanks again bugman,
i'll be going out soon and that gives me more stuff to check out, i'll keep you posted


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## whyme (Jul 4, 2005)

"oh and i forgot to ask, did you check the spark plug for spark? as long as it has spark, it should fire if its getting gas as long as the flywheel keys good."

i hadn't even gotten to spark yet mainly because i was just trying to get it to turn over properly before i worried about it actually firing. i am however changing the plug today so i'll let you know


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## bugman (Aug 12, 2004)

well. the old plug may hurt it some in performance, but as long as you are getting spark, all you need is gas next.


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## whyme (Jul 4, 2005)

nothing rusted up new plug, cleaned up carb, changed oil, but still wont spin flywheel, guess i'll take the starter in and have it checked out... is it possible that the starter works but not well enough to spin the flywheel?


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## bugman (Aug 12, 2004)

not saying the new plug was rusty...the old one may have been carbon coated, and rusty maybe. is the starter turning, and engaging the flywheel starter ring teeth? yet not spinning it? like i said, weak or low cranking amp battery will have a hard time. this is as long as the flywheel turns well by hand....


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## whyme (Jul 4, 2005)

the old plug was rusty and needed replacement, the starter turns and the gear enguages the flywheel, it will spin it until the compression stroke or not at all if it's starting on the comp stroke. the battery is brand new and fully charged


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## whyme (Jul 4, 2005)

also i've eliminated the possibility of anything to do with the selenoid, it's been replaced, and i also tried this by jumping straight to the starter


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## bugman (Aug 12, 2004)

ok, what cranking amp battery? the rating...... also, with high compression engines like that, i wouldn't use no less then 275. you could jump it from a car, to give it more juice. though have you tried charging the battery? even though they are new....they mostly sit there and aren't fully charged to begin with most of the time. it just sounds like your battery at this point, also the battery connections, make sure they are nice and tight, and clean! one way i keep em from corroding over is wd-40 on the contacts, and from there on out didn't have a problem. use a wire brush to clean em up good if they aren't clean.


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## whyme (Jul 4, 2005)

hey bugman
i believe it's a 275 but i'll have to check to be sure. i just got back from the tractor place and the starter passed the bench test they said it ran like new. they told me to check my belts which i did, and the valves, which i did. at this point i'm at a loss. also i tried starting it using my car battery and it did the same thing


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## scrench (Dec 8, 2004)

i would double check the valves


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## whyme (Jul 4, 2005)

at tdc both valves are loose, unfortunantly i have no way to gauge them, to make sure their within tolerance


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## bugman (Aug 12, 2004)

well, if you can get them to come out, or get it in to the small engine shop, they would be able to adjust them.


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## scrench (Dec 8, 2004)

easy just set them by feel ,,,,,, back off the nut a little then loosen the screw inside the nut then tighten the nut until there is just a little bit of play in the pushrod then tighten the screw down then tighten the nut a little more might take a couple of tries to get it where you want it also make sure both valves are on the lowest side of the cam when you adjust them , you can turn the engine where the intake is fully open and adjust the exaust then with the exaust open all the way adjust the intake just take your time you will get it make sure you dont get them too tight they just need a small ammount of clearence you can do it


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## whyme (Jul 4, 2005)

ok thanks
guess i'll try this tomorrow and worst case scenario i can take the engine off and run it to the pro's


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## whyme (Jul 4, 2005)

ok well i went and pulled the head , and think i found the problem, the cylinder walls were pretty much dry, so i poured a small amount of oil in and worked the flywheel by hand and it's spinning pretty good now. unfortunantly when i took the starter off i lost the snapring so i can't try it until i get one tomorrow


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## bugman (Aug 12, 2004)

well, valve timing on them will catch em, doesn't really matter if the bore's dry with no oil, it wouldn't hold it back from starting by much. unless it had a coating of rust, then it wouldn't turn over or turn over a little harder. in which case penetrating lube will do. as well as oil, but with the penetrating lube you can just spray it.


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