# B&S 18hp slow cranking - hard to start



## gbartmi (May 6, 2008)

I have 2004 Murray riding lawn mower with a 18 hp ovc B&S engine. It has recently been getting harder to start, as it has a very slow turnover/crank of the engine. It has a new battery, with a high crank rating and is fully charged. Runs great when started.

Would it be a weak Solenoid, Starter, or other?

Thanks!


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## bozodog (Nov 27, 2009)

Before replacing anything, I would trace, remove, and clean all the cables and wire connections involved in the starting system.


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## K-B (Oct 24, 2005)

Checking the wires is a good idea, but I suspect that it's past time for a valve adjustment.


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## bozodog (Nov 27, 2009)

> a very slow turnover/crank of the engine. It has a new battery, with a high crank rating and is fully charged. Runs great when started.


To me, it's unlikely valve lash would create the above symptoms. 

Runs great..
New battery..

Slow turnover, cranking... Start with cleaning cable connections, don't forget kill switches. Then have the starter checked out.


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## SABL (Jul 4, 2008)

Oil viscosity and temperatures can also affect cranking speed. Check OEM guidelines for reccommended oil.


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## K-B (Oct 24, 2005)

bozodog said:


> To me, it's unlikely valve lash would create the above symptoms.
> 
> Runs great..
> New battery..
> ...



I've seen it quite a bit. We've even had brand new mowers refuse to start on the floor, due to improper valve adjustment at the factory. The symptoms will be the same as a low battery, in fact the first time it happened we tried several different batteries until we realized that's not where the problem was.


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## gbartmi (May 6, 2008)

Thanks for all the advice! I did not think of the valves being bad, as once I'm able to get it started, it runs strong and will start right back up, if I must turn it off for a minute or so.
The slow start sounds more like a weak battery, as the engine turns over in a "wub-wub" action. It cranks/spins once-twice, then stops, I release the key and turn it back on with the same results/sound. Eventually, it actually will start, sounding/acting like it caught a full charge...spins/cranks right up and runs fine. This slow starting seems to be getting worse as time goes by...

The battery has a complete/full charge. Also, if I try to turn it on too frequently, the bottom of the starter will put out a wisp of smoke...time to ger a new starter, too!

Thanks!


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## mikeinri (Dec 2, 2009)

As mentioned, it can never hurt to clean and inspect all cables and connection points. Battery cables are known to sometimes corrode from within in some automotive applications, the principles are basically the same here.

Mike


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## K-B (Oct 24, 2005)

gbartmi said:


> Thanks for all the advice! I did not think of the valves being bad, as once I'm able to get it started, it runs strong and will start right back up, if I must turn it off for a minute or so.
> The slow start sounds more like a weak battery, as the engine turns over in a "wub-wub" action. It cranks/spins once-twice, then stops, I release the key and turn it back on with the same results/sound. Eventually, it actually will start, sounding/acting like it caught a full charge...spins/cranks right up and runs fine. This slow starting seems to be getting worse as time goes by...
> 
> The battery has a complete/full charge. Also, if I try to turn it on too frequently, the bottom of the starter will put out a wisp of smoke...time to ger a new starter, too!
> ...


Did you check the valves? What you're describing is exactly what we've experienced. If you manually rotate the engine past the compression stroke, it will start, but barely. Once running, it runs normally.

Sounds like the starter is either working too hard, or there's also the possibility that the starter is worn out and unable to turn the engine over fast enough.


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