Briggs and Stratton 18.5 Single Cylinder OHV Engine won't turn

swinginscott

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  • / Briggs and Stratton 18.5 Single Cylinder OHV Engine won't turn
Hello all, I've spent a _lot_ of time searching through this forum post by post, and while I never found my particular problem I'm sure it's in here somewhere. Problem is I can't find it. I am extremely novice at engine repair, so your patience is appreciated.

Here's the problem, I bought a riding mower (Craftsman Dyt4000) that wasn't starting. After some troubleshooting, I narrowed it down to either the starter, or the valves being out of adjustment. So after talking to a local repair man, and watching some youtube videos, I attempted to adjust the valves. I also replaced the starter (an aftermarket one from DB electrical) and voila! The mower started.

So I bring it home after this success, and was mowing for about 45 minutes without issues. Then someone else started mowing, and I started with the weed wacker. They said they shut down the mower with the key, put on the parking brake, and when they tried to start it again it wouldn't.

I tried manually turning the engine by placing my palm on the top and spinning it, and it's STUCK with a capital S. I disconnected and removed the spark plug, but still can't turn it, at all. Not even 1/1000th of an inch. Before I adjusted the valves this would happen on a certain stroke of the engine and not go anymore, only with the spark plug out it would spin freely.

Before all of this I did check the oil and air filter, and this is a brand new spark plug as well.

I assume that this engine not turning all of the sudden is some sort of compression problem, but I'm not sure if there's a way to manually release the compression. I assume that of the two valves one is intake, and one is exhaust so if I can somehow manually open the valve let me know.

I'm just stuck as to where and how to start troubleshooting this particular problem.

Here is the mower information:
Craftsman Dyt 4000, model 917 274632

Engine: Briggs and Stratton 18.5hp model 31P777, Type 0348E1, Code 0409022E

The starter I just put in was part 693551.
 

KennyV

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  • / Briggs and Stratton 18.5 Single Cylinder OHV Engine won't turn
With the spark plug removed... There is No compression... If it is not turning with the plug removed... you have something serious wrong.
You say you checked the oil level earlier... what is it Now? Is there any fuel in the crank case?
There is either something internal OR external jamming the engine... Hope it is external ,check the belts that the engine drives... :smile:KennyV
 

swinginscott

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  • / Briggs and Stratton 18.5 Single Cylinder OHV Engine won't turn
With the spark plug removed... There is No compression... If it is not turning with the plug removed... you have something serious wrong.
You say you checked the oil level earlier... what is it Now? Is there any fuel in the crank case?
There is either something internal OR external jamming the engine... Hope it is external ,check the belts that the engine drives... :smile:KennyV
Hmm, unfortunately, that's what I was afraid of......but I was hoping.

The oil level is fine, it was between the dots before it was stuck, and it's still registering in the same spot.

I'm not really sure what a crank case is, I'll do some research on that and check though.

I'll check the belts, in the next day or two (busy time at work) and I'll let everyone here know.
Thanks for the reply.
 

KennyV

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  • / Briggs and Stratton 18.5 Single Cylinder OHV Engine won't turn
Since it is not moving Any... CW or CCW ...
It is likely that a belt is broken and jammed in the pulleys..
The starter bendix is jammed in the fly wheel...
or the piston is stuck in the cylinder....
There are only a couple remote possibilities, but I'd bet on one of the 3... :smile:KennyV
 

upnorth

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  • / Briggs and Stratton 18.5 Single Cylinder OHV Engine won't turn
could also be a spun bearing on the crankshaft. a broken wrist pin and a bent connecting rod will bind it up too.
 

reddragon

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  • / Briggs and Stratton 18.5 Single Cylinder OHV Engine won't turn
Kenny's got it right....check all external possibilities first....then take a deep breath.....internal issues are usually terminal :frown:
 

swinginscott

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  • / Briggs and Stratton 18.5 Single Cylinder OHV Engine won't turn
Thanks for the advice, I finally have a moment to breathe tomorrow evening (or Saturday morning) and will have time to get the cowling off and take a look.

I appreciate all the responses, I'll keep you posted.
 

swinginscott

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  • / Briggs and Stratton 18.5 Single Cylinder OHV Engine won't turn
Great news everyone, with your help I fixed it!

Turns out it was the little cog on the starter was stuck point to point with the flywheel cogs (I'm sure there are official names for those, but I'm a novice and not scared to admit it).

After the initial "Ah man I just got this working!" your advice helped calm me down and think rationally about the fix. I appreciate the willingness to share the knowledge and help.

Thanks.
 

upnorth

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  • / Briggs and Stratton 18.5 Single Cylinder OHV Engine won't turn
starter drive is called the BENDIX. Flywheel thingie is called the FLYWHEEL GEAR. CRANKCASE is where the drive shaft and connecting rod journal spins. CONNECTING ROD JOURNAL bearing surface on the lower end of the piston connecting rod. Any help?
 
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