Craftsman Lawn Tractor -briggs stratton 2004

astephenOctober 9, 2007

I was driving my lawn tractor the other day and when I stopped the engine it backfired (frequently happens). When I went to re-start the engine the starter would crank the engine very fast but the motor would not start (it would backfire very loudly if starter was engaged too long).

I checked for spark and gas delivery and both seem fine.

I found a mouse next near my air filter and a mechanic told me my engine was blown because of that (why would it blow when I turned off my engine....).

I opened up the over head valve cover and found that the top valve was very loose at TDC (maybe 0.030").

I tried to fix the problem but the keeper rings fell out and now I can't seem to get them back on the valve.


1) Does this sound like a valve problem or a blown motor? How do you determine?

2) How do you get the keeper rings back on the valve? Is there a tool or do you need to remove the head?

3) This tractor only has 45 hours on it and it's out of warranty. Has anyone had any luck dealing with Sears when it comes to a blown motor with so little hours?

Any input would be greatly appreciated. I hate to think I've ruined a fairly new tractor...

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It's unlikely the keeper rings "just fell off". If you did something extreme, they could have come off. (Only you can judge that.)

There is a valve spring compression tool, however even using that, it would probably work best with the head off. I don't even know if it's possible to compress the spring and get the keeper on with the head on. ??

Try pulling the valve stem out from the top (thinking maybe, the valve head popped off. I don't even know if this ever happens.) Maybe, if the keeper ring came off very easily, it might indicate that.

"Blown engine" would usually mean something serious in the bottom end, I would think. If the pistons and push rods go up and down, I'd tackle the valves first.

Let's see what the pros have to say.

    Bookmark   October 9, 2007 at 1:54PM
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Engine Model & Type numbers are always handy so we know exactly which engine you have.

Without looking at the engine, it's hard to know exactly what "blown" means. It might be as minor as a "blown" head gasket (not uncommon) or very major damage to the internal parts.
Why not ask the "mechanic"?

You pretty much have to remove the head to reinstall the valve keepers. Not a major job if you have some mechanical aptitude. You could probably do it without the valve spring compressor if you have strong fingers and a 3rd hand.

You can down load a pdf IPL from Briggs at the link below.

BTW, on Briggs OHV engines, the valve lash is checked with the piston 1/4" PAST TDC.

I can't speak for Sears how they would deal with the situation. You might ask them or Briggs, since it is an engine issue.

Here is a link that might be useful: Link

    Bookmark   October 9, 2007 at 2:06PM
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Now that you have given a brief description of the scenario, it would be appropriate to post the engine model # and type # from the engine itself.

    Bookmark   October 9, 2007 at 2:11PM
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Sorry the engine type is 18.5hp, OHV INTEK PLUS.

I'm surprised at how quickly and willingly people are at answering my e-mails.

Anything to help me out would be good.

    Bookmark   October 9, 2007 at 4:54PM
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Model number 917.273642

    Bookmark   October 9, 2007 at 4:55PM
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That engine should be a-

SAME engine as in the "Valve lash adjusting" thread!

    Bookmark   October 9, 2007 at 5:30PM
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Yes, it is the 31P777-0348-E1. Can someone link me into that thread? I'm new to garden web and I'm afraid I'm not that good at navigating. Sounds like I might be on to something though......

    Bookmark   October 10, 2007 at 8:32AM
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It's down the list about 5 threads.

Here is a link that might be useful: Valves adjusting

    Bookmark   October 10, 2007 at 8:59AM
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