Craftsman 15.5 HP B&S turns over slow, but will not start

sillyboy

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  • / Craftsman 15.5 HP B&S turns over slow, but will not start
My Craftsman B&S 15.5 Turbo Cool was running & starting fine until 3-4 weeks ago. It was turning over real slow but would finally start. I bought a new battery and it turned over a little faster, and started. 2 weeks ago, when I started it, it backfired once through the exhaust, and started, but turned over slowly. Last week, barely turned over and would not start. I tightened the hot red cable where it connects to terminal block (under the hood), that the other red cable side goes to the starter. The mower started up, but slowly turned over.

Today (8-21-11) , I took apart all electrical connections from the battery (fuse is good) to the starter, and cleaned them. Mower still turned over slow and then just would not turn at all. When the mower was running, and I stopped and got off of it, it would start right back up.

I was thinking electrical, now thinking valves. Any ideas?? Thanks

BTW I believe this is a 1999 model as the picture on the manual looks just like mine. Looked it up and downloaded the manual last night. Didn't need the manual till now. Thanks

The battery is showing 12.45 Volts across the terminals.

Model 917.256524-EZ3
S/N 100996B 012199
B&S 15.5 HP Turbo Cool
 

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reddragon

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  • / Craftsman 15.5 HP B&S turns over slow, but will not start

sillyboy

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  • / Craftsman 15.5 HP B&S turns over slow, but will not start
SOUNDS LIKE A VALVE ADJUSTMENT IS IN ORDER....if its never had one...also..when a float needle leaks ..it can fill the cylinder with gas and stop it from turning....you can check by pulling the plug and crank it....see if it sprays gas....heres a valve adj. tutorial ( HOW TO ADJUST VALVES) FIX HARD TO START Lawn Tractor with OHV Briggs Engine- MUST SEE- Part 1/2 - YouTube

Hi reddragon, I am going to look at this tutorial as soon as I'm done here. Thanks.

Also, I was talking to a friend and he said that it might be the starter (it's the original). Is there a way to check the starter? He said that there may be an issue with "not enough" cranking amps. About 3 weeks ago I jumped started the mower with my car and I thought a NOS system was installed on the starter! I'm just trying to cover all bases, kinda at once, because money is short, and it keeps raining a lot here (20 miles outside of Pittsburgh, PA). Usually the grass is burned out till about the end of Sept, when it starts to rain again.

Thanks again
 

reddragon

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  • / Craftsman 15.5 HP B&S turns over slow, but will not start
a load test will confirm the battery's strength....you can have it done at an auto parts place......take your spark plug out and then crank it....see if the starter is weak then...it should spin furiously when cranked
 

sillyboy

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  • / Craftsman 15.5 HP B&S turns over slow, but will not start
a load test will confirm the battery's strength....you can have it done at an auto parts place......take your spark plug out and then crank it....see if the starter is weak then...it should spin furiously when cranked

I just got back from the auto parts store. The battery (bought 8-15) is weak from cranking. Told to charge it up, and take it back tomorrow. I adjusted the valves (very touchy), and cranked it with the plug out. It spun, but not furiously, but nothing like when I jumped it from my car with the plug in (that was furious!). When the battery got so low, the solenoid started clicking, I then took the battery up to be checked.

Is there a charging circuit in the mower somewhere? I not that good with schematics.

Thanks
 

reddragon

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  • / Craftsman 15.5 HP B&S turns over slow, but will not start
what brand is the battery and what cold cranking amps?....heres a manual [ u might have to enter jibberish] http://www.hammerwall.com/Download_Manual/37749/ what was touchy about the valves?...how far out of spec were they?......theres no charging system...it just maintains battery so it wont drain...thats one of the biggest misconceptions in the auto industry..!
 

sillyboy

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  • / Craftsman 15.5 HP B&S turns over slow, but will not start
what brand is the battery and what cold cranking amps?....heres a manual [ u might have to enter jibberish] http://www.hammerwall.com/Download_Manual/37749/ what was touchy about the valves?...how far out of spec were they?......theres no charging system...it just maintains battery so it wont drain...thats one of the biggest misconceptions in the auto industry..!

There are two sets of specs, for valve adjustment. In the B&S manual it's .003 to .005 for the intake: and .005 to .007 for exhaust. In the Sears Craftsman Manual it's intake .005 to .007: exhaust .009 to .011. I used the Sears manual specs, had the battery charged, and it started right up. Spun fast too b 4 it started.

For some strange reason I think that the system is not keeping my battery maintained. I'll find out after I cut the grass a few times. Any thoughts?
I might be chiming in again.

Thanks for the help.:smile::biggrin:
 

reddragon

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  • / Craftsman 15.5 HP B&S turns over slow, but will not start
ok....just keep us imformed...try and record what the symptoms are..it makes it alot easier when you do this over the internet :thumbsup:
 
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