Craftsman lawn tractor starting problem

[Rivets]

If the valve clearance is too great, the compression release will not work properly, which will not let the engine turn over properly on starting.

 

[pugaltitude]

If the valve clearance is too great, the compression release will not work properly, which will not let the engine turn over properly on starting.

Couldnt have put it better myself.
Check the clearances and make sure the decomp is working.

 

[paejkirk]

I think you guys have gone past my level of experience (which is not hard). Can you explain "compression release" and "decomp"?

This is starting to sound like a trip to the repair shop is in-order.

 

[Old Goat]

I have a Craftsman lawn tractor with a 17 1/2 HP Briggs and Stratton engine that has been experiencing starting problems for a couple of years. Basically, the problem is this: I have to charge up the battery before I can start the tractor - if I don't, then the starter doesn't turn the engine over fast enough to start. Now, I assumed the obvious - that the battery was wearing out. This fall I bought a new battery and the problem persists. I am now starting to suspect that I have a bad starter solenoid or a weak starter. I checked my battery before starting the tractor this weekend and the charge was 12.56 volts, which from looking on the internet, seems to be a normal charge for a 12 volt battery. However, the starter wouldn't turn the engine over fast enough for it to start. Then I charged the battery for awhile and checked the charge again. The battery measured 13.48 volts, which then was able to turn the motor over fast enough for starting. Even at this voltage, the starter hesitates a bit - when you turn the key, the starter turns over once, then hesitates for a second or two, then starts cranking the engine. Does anybody agree with my suspicions, and what should I do to remedy this?

Experienced that for years until I replaced those 200 CCA batteries with this bad boy.

Briggs & Stratton® Lawn & Garden Tractor Battery, 420 Cranking Amps - 4700042 | Tractor Supply Company

What happens when you jump start it off the car?

Charles

 

[Rivets]

Decomp or compression release are the same thing. An internal mechanism opens the exhaust valve slightly when the engine is turning slowly, as in starting. This reduces pressure in the cylinder, to allow for easier starting. Yes, this mechanism can fail, but in my opinion it is highly unlikely in this case. As I said earlier, check your valve clearances. If your battery is more than 3 years old or less than 300 CCA, it may be part of the problem, but in my opinion not the solution. If you don't feel confident in adjusting valve clearance, I would see my mechanic. You can do more harm than good if adjusted wrong.

 

[motoman]

I just browsed the garden forum for fun. If you don't believe Rivets go there and read page after page of miraculous fixes for "no starts" -- adjust the valves

 

[SeniorCitizen]

Experienced that for years until I replaced those 200 CCA batteries with this bad boy.

Briggs & Strattonｮ Lawn & Garden Tractor Battery, 420 Cranking Amps - 4700042 | Tractor Supply Company

What happens when you jump start it off the car?

Charles

If the compression relief isn't working the same thing happens when jumping from the car or a Mack truck. The reason being is the lawn and garden tractor starter is good for XXX number of amps. ( usually less than 300 ). Leave the key in the start position long enough and you'll see the weakest component via smoke plume.

 

[motoman]

I stand by what I said until someone can prove me wrong without physically altering the switch. Even then if the key switch is bad, removing the key will make no difference. Just an old fart, wrench monkey, who does know a little about electricity and electrical components. Just sick of seeing posts leading people in directions that go no where. But you know me, I like to start trouble.

When not in use my Intek has sat locked up in garage since 2004 with the key in the ignition. Never a problem. I recently suggested on another thread how to check if something is consuming current with the key off. It's a common technique in auto repair to detect "parasitic drain." Easy,but you need a VOM (volt ohm meter) which has a "current" capability. (Just pull the red and black leads out of the 2 main sockets and put them into the "current sockets.")

 

[Old Goat]

If the compression relief isn't working the same thing happens when jumping from the car or a Mack truck. The reason being is the lawn and garden tractor starter is good for XXX number of amps. ( usually less than 300 ). Leave the key in the start position long enough and you'll see the weakest component via smoke plume.

But, I was asking the original poster (paejkirk) that question. Not you.

Looking for the easiest route to locating the trouble.

Charles

 

[paejkirk]

I haven't tried jumping the tractor off of a car. Like I mentioned on my first post, if I charge the battery up to ~13.5 volts then the tractor starts up fine. I do notice that the engine turns over faster than it does at 12.6 volts. It may be due to the compression release not working right as some have mentioned - if so then I guess the higher voltage to the starter overcomes the failure of the compression relief to release pressure.

But back to my original question - could a bad connection, bad starter solenoid, or weak starter not also cause this problem. Do starters ever weaken over time? Just trying to consider all possibilities.