Starter will not turn engine sometimes

pchalpin

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That is interesting, I suppose if the compression is strong the starter might not have enough torque to turn the engine and after it bumps a few times the valves might open enough to let the compression decrease, thereby letting the starter get a few revolutions in, tyhereby starting the engine.
How would I test for this situation?
I took of the valve cover and checked the valve clearances. They were way off. Set them to .0004 regardless of what the manual says. Problem solved. Make sure you check and set the clearance at top dead center of the compression stroke.
 

bbirder

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That is interesting, I suppose if the compression is strong the starter might not have enough torque to turn the engine and after it bumps a few times the valves might open enough to let the compression decrease, thereby letting the starter get a few revolutions in, tyhereby starting the engine.
How would I test for this situation?
Don't try testing to prove or disprove. Compression release on many engines works off of the valve settings. Won't attempt to explain at this time. Adjust your valve settings and crank her up. Your best bet to solve your problem and save your battery!
 

Boyde

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Anybody heard of this? I looked at buying a new starter, just researching so far. The new starters have 9 teeth instead of the ten teeth, suggests more torque to turn that engine. This would suggest there might be a common issue with these engines. Any thoughts?
 

ILENGINE

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Very common starter issue. Just replaced the starter on the BIL mower a month ago because that exact same starter that you are having issues with sheared the shaft off even with the housing. Issue totally set me off so I rewired his mower for the Command solenoid shift starter

 

Boyde

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Some more info on this issue: I jumped the solenoid today and the same issue was evident, so that eliminates the solenoid. I put a battery charger to boost the battery, this caused the starter to spin the engine every time, so this points to the amount of cranking amps being drawn by the starter. It also suggests that there is nothing wrong with the starter.
So I am thinking the compression is too much for the starter to turn unless it can draw enough amps.
The battery is rated at 400 Cranking Amps, 350 CCA.
 

slomo

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I took of the valve cover and checked the valve clearances. They were way off. Set them to .0004 regardless of what the manual says. Problem solved. Make sure you check and set the clearance at top dead center of the compression stroke.
Should be like 0.004" or 0.006", not 0.0004. Possible typo?? Makes a difference.
 

slomo

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Take the battery to an auto parts store. They will check it for free. They can fail at any time. Nice work on keeping a maintainer on it.

Also remove the spark plug/s. Try cranking it over. Engine should rotate like a top.

Shot in the dark, remove the oil dipstick. Smell for fuel. Could be hydrolocking the cylinder?? Watch for fuel kicking out of the spark plug hole when you crank the engine. Report back here.
 

ILENGINE

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Some more info on this issue: I jumped the solenoid today and the same issue was evident, so that eliminates the solenoid. I put a battery charger to boost the battery, this caused the starter to spin the engine every time, so this points to the amount of cranking amps being drawn by the starter. It also suggests that there is nothing wrong with the starter.
So I am thinking the compression is too much for the starter to turn unless it can draw enough amps.
The battery is rated at 400 Cranking Amps, 350 CCA.
Due to the issue with possible worn shaft starter bushings it could also lead to the starter dragging due to the armature hitting the magnets requiring extra amps to turn.
 

Boyde

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Further to this discussion. I have continued researching, and it appears that the compression is a common issue with these engines. It appears that setting the value clearance to a tight .004" to allow the exhaust valve to open a fraction of a second sooner will release some of the compression, thereby allowing the starter to spin the engine with less amps.
Also I have determined that there is a couple of design flaws with the starter, there are three generations of the starter, the third generation solves this issue as well as a few other issues. The third generation has nine teeth instead of ten (More torque), a thicker shaft(less breakage) and a bunch of other things.
The third generation costs money, so I will not be doing that one right away (my starter still spins sometimes). I shall tackle the valve setting first, if that is not enough, then I shall reevaluate a new starter.
 
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