# Need Help w/ Briggs 10.5HP *Cranks*No Start*



## Colt1911 (Mar 29, 2009)

Hi guys, looks like a cool forum  Glad I found it too, cause I have a bit of a problem with a B&S 10.5HP that wont start  

It all started (no pun intended) when I got this free riding mower. Guys says 'Last time I used it, I went to drop the deck, and the motor died. Maybe you can do something with it. So I bring it home, and all it needed to run was fix some corroded wiring, and a 3 inch piece of fuel line. Runs great.

So, I get air in the tires, wash it down good, you know clean it up a bit. The next day I warm up the engine, and thought I would see what condition the cutting system was in. Take it out in the yard, drop the deck, start cutting. Great. Cuts good, pullys need grease, ok. Then after 4 or 5 minutes the engine died like it was out of gas. I had only been putting a splash of gas in at a time, but it wasnt out. grabbed a battery, tried to restart. Backfire. Tried again, another backfire. :? 

So now I start checking the various systems. There had been so much rust on the balancer when I cleaned it up, and I had gapped the mag a bit too wide, leaving my spark a little weak. I trimmed that up. Now even better, hotter spark. Also noticed that I accidentally left off a rubber hose from the port off the manifold (PVC?) to the carb. Corrected that. Fuel delivery is perfect, although the float in the bowl was stuck when I got it from the gum that had accumulated inside. It is definiently not a fuel problem.

So now she cranks, and no start, no backfire, nothing  It sounds like it is breathing from under the balancer, I get a little pressure when I hold my hand over the muffler, but I can keep my hand there. I dont see any other holes in the muffler, but I havent examined it closely, it's not completelty rusted out or anything.

So I'm guessing that my compression is shot, but where :?: I have rebuilt automotive engines, but have only casually seen the internals of these type small engines a few times. Anyway, is there a seal under the balancer that could be blown? Or have I blown a head gasket? What else could cause this? I'm not realy sure what even drives the valves in these things, guess I'll go do a bit a research when I'm done here.

Also, if I'm going to need parts, where is a good parts supplier online? I've had a hard time also finding good refrence material online aswell.

Its a:

1998 Mastercraft Riding Mower (some private label) it says "Coast To Coast Hardware" on the side
Briggs & Stratton 10.5HP vertical shaft w/starter
Dinky 32" cut

Thanks for the help!
Colt


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## golftech (Jan 3, 2009)

The engine serial number,etc, would help,but does it look like this:http://www.tulsaenginewarehouse.com/catalog/briggs/bsvert/28b700.html
If so,I'd check the compression properly,with a gauge,and if low or none, pull the head and see what's going on with the valves.

I see you posted on another forum and got the same answer from Briggsguy. :>)


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## Colt1911 (Mar 29, 2009)

Yes, I think its a bit older model though. Sometimes when I need a fast answer I will post on diff sites. I really appreciate the replies 


Model: 257707
Type: 0143 01
Code: EI101731

edit

Will check comp in a minute, what the spec?

/edit


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## phillipmc (Jan 27, 2008)

Normally if you get compression 90 PSI and above your in ok shape. I generally shoot for 100 and above on engines with that displacement and above. Being this is an older engine it most likely doesn't have a automatic compression release. If your compression and spark are good check your flywheel key to make sure it isn't sheared. If its good then try squirting a little gas directly into the carb and try cranking it.


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## Colt1911 (Mar 29, 2009)

*Thanks*

yeah, I'm thinking the head gasket is shot. Possibly I have a stuck valve. Will let you know what I find.

Thanks for the replies 

Colt


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