Battery good, but only starts with jump

[bouttree]

I had the same problem....I thought I had a battery malfunction sometimes the engine would spin for a while if I jumped the battery.Then click click click..... This was a false result of jumping the engine, actually the engine valves would move enough sometimes to let off built up pressure so the engine would spin then the valves would get "stuck again and the flywheel would not spin....click click....I finally figured it out when I removed the spark plug then turned the start key. The flywheel would spin without a problem. My valves were way out of adjustment!!!!!! Please let me know if your engine is now running and what fixed it or notify me when you have found your problem. I also inspected the starter brushes and was amazed they were still in good shape as is the solenoid. I have burned out a new battery.
Dennis

Craftsman 4500. 24 hp Vtwin. 42" deck. 7 years old. About 380 hours. I change oil, filters, spark plugs, etc every year. Last year had Sears come change deck belt and 1 bad spindle. Buy new battery every spring.
Bought new battery end of March. Mower started off battery. Did not mow in April because no rain meant no grass. Finally went to mow 2 weeks ago and would not start off battery. Started off jumper and ran fine for an hour. Turned off. Attached spreader. Would not turn on off battery. Started off jumper. Spread. Back into shed.
Last week I hooked the battery up to charger so it would be ready for weekend. Weekend comes, time to mow again. Voltage meter said 12.9 volts. Put battery in mower, will not start off battery. Remove battery and go to store where I bought it. They say battery holds charge fine. Go home. Top off battery with charger for an hour. Back into tractor. No good off battery. Starts fine off jumper.
So do I need a new starter motor? Check for bad wiring? Check for winter debris under the engine housing?
Or maybe just bite the bullet and buy another battery and keep this one charged between uses?
Much thanks for any suggestions.

 

[bouttree]

Defiantly try adjusting the valves

Have you checked the valves?
Will the engine turn at all with just the battery?

 

[mechanic mark]

http://www.searspartsdirect.com/Cra...actor-Parts/Model-917287260/0247/1509200.html check out wiring schematic

Remove battery & take to local auto parts store & ask them to load test battery, you should not have to pay for this test, they have machine to test battery. Sounds like alternator failure. Also adjust valves engine cold per engine manual specs. as mentioned in above posts.


http://www.briggsandstratton.com/us/en/support/manuals/results?NTT=445677-0725* engine manual & parts check out page 8 in engine illustrated parts list, alternator is located under flywheel, be sure to get correct numbers from old alternator before purchasing a new part. Always use OEM B&S parts.

http://www.amazon.com/Briggs-Stratton-273521-REP-MAN-INTK/dp/B002WNZY6S in case your interested, repair manual your engine

 

[bertsmobile1]

To test the stating circuit, remove spark plugs and try the starter.
If the motor spins up fine then the whole starting electronics system is fine & dandy and the problem is either in the engine or the starter motor itself.

Try turning the engine over by hand without and with the plugs in
If you can not turn it over reasonably easily by hand then as every one else has said, adjust the valves you will find the gap has gotten a lot bigger than it should be.

I you can turn the engine over by hand with plugs in easily then have a look at the starter motor, they can get an accumulation of crud down the bottom that can damage the brushes or prevent them from working properly.

Just a word of warning, take the starter off the mower and after cleaning it, do the disassembly inside a carton as those springs can pop off and go for miles