B&S 16hp hard to start/turn over

[threeputtpar]

I have been given a free Toro 16-38XL because my friend is tired of it not working. The symptoms are that even with a brand new battery that reads 12.55 volts it will not turn over more than one revolution at a time and then stop at the top of the compression stroke.

I have a new battery, new starter solenoid (the first one was good too), checked and cleaned all cables between the battery, solenoid and starter, have verified that the valve clearance is set to the proper spec, and I pulled and had the starter tested and it was good. I'm stumped at this point as to what to diagnose next.

I've worked on this tractor in the past and a year ago it would spin over and start just fine, it was the transmission that was the problem. I fixed the shift fingers in the trans and now it doesn't want to start.

Any suggestions? Thanks.

 

[Eddie]

Test the starter and current draw when cranking.

 

[JimPghPA]

Pull the spark plug(s) and see if it still is hard to turn over.

If it cranks fast with the spark plug(s) out check the gap on the valves.

If it cranks slow with the spark plugs out check what the engine turns and also look for rust in the cylinder(s).

 

[Rick in PA]

Compression release? I have a buddy at work who picked up a riding mower cheap because the compression release wasn't working. I believe he said they were fussy to set right, but when set right they work well.

 

[slomo]

Valve adjustment probably waaaaay past due. Compression release would do it also. Lastly combustion chamber full of carbon might do it. Pull the head off and see. Last push mower I got there was a TON of carbon inside and nearly plugged up the plug hole entirely.

slomo

 

[andyd]

Partially sheared flywheel Key? Timing is way advanced?

 

[Wheel]

I vote for bad/plugged compression release.

 

[tig1]

Here is an article on the compression release system . I have had the same problem with my 21HP Briggs. Engine would not turn past the compression point with battery power.

http://hubpages.com/living/Hard-to-start-Briggs-and-Stratton-engine

 

[AnthemBassMan]

Another one banking on the valve lash needs adjusted. This wouldn't by any chance be an Intek or other OHV would it? I believe the valve lash should be between .004" and .006", but double check the specs before adjusting.

L8R,
Matt

 

[threeputtpar]

Thanks for the replies so far. The valve lash is set at .004 intake and .006 on the exhaust. It was also dumping fuel into the oil that when I pulled the plug out came a cup of gas.

The one time I did get it to turn over it backfired and started for 5 seconds. The flywheel key is a possibility.

 

[AnthemBassMan]

After removing and replacing the spark plug, does the engine turn over better? If it does now, it may be getting hydro locked from the excess fuel getting into the cylinder. If that's the case, check the float and needle/seat to make sure ther are closing like they should.

L8R,
Matt

 

[threeputtpar]

Without the plug it turns over and over. I've fixed the carb and there's no fuel in the tank, just trying to get it to turn over with the plug in.

 

[Merkava_4]

Originally Posted By: tig1
Here is an article on the compression release system . I have had the same problem with my 21HP Briggs. Engine would not turn past the compression point with battery power.

http://hubpages.com/living/Hard-to-start-Briggs-and-Stratton-engine


That is actually some very useful information, but that is the ONLY useful post you've ever posted, ever!

 

[DSparks]

Starter....

 

[sweezy722]

1. Make sure blades are not engaged and trying to turn when you turn starter.
2. Use jumper cables hooked to the battery to make sure battery is good.
3. Starter may be bad or sometimes taken apart and cleaned

 

[Rand]

Originally Posted By: Merkava_4
Originally Posted By: tig1
Here is an article on the compression release system . I have had the same problem with my 21HP Briggs. Engine would not turn past the compression point with battery power.

http://hubpages.com/living/Hard-to-start-Briggs-and-Stratton-engine


That is actually some very useful information, but that is the ONLY useful post you've ever posted, ever!

This from the king of worthless posts AND THREADS....



Sounds like you are on the right track so far with the repair.

You need to figure out if the starter is weak or the engine is hard to turn over.. then narrow it down from there. Lots of good advice in here.

 

[HerrStig]

Shorted starter windings are my bet.

 

[threeputtpar]

The starter tested out good, it seems that it's just not getting enough juice to turn the engine over enough to get it past the compression release the first time. Or the intake is not adjusted correctly and the compression release is not functioning.

The starter was tested on a rig designed for automotive starters, so would that mean that it would be putting out more amperage than the typical 275CCA that the lawn tractor battery puts out? Would that hide the starter's weakness?

 

[tig1]

Originally Posted By: threeputtpar
The starter tested out good, it seems that it's just not getting enough juice to turn the engine over enough to get it past the compression release the first time. Or the intake is not adjusted correctly and the compression release is not functioning.

The starter was tested on a rig designed for automotive starters, so would that mean that it would be putting out more amperage than the typical 275CCA that the lawn tractor battery puts out? Would that hide the starter's weakness?


The compression release is part of the exhaust valve, not the intake.

 

[yeehaw1960]

Go to YouTube and watch a couple videos on adjusting valves on a Briggs and Stratton. It's very, very easy if you follow the instructions it will immediately correct the problem.