Briggs and Stratton 17.5 valve adjustment help

indyyy

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I have a 2013 Troy Bilt Pony 42" lawn tractor with the Briggs and Stratton 17.5 engine. It does the thing where when i turn the key it turns a little stops at compression turns a little more stops again at compression, etc. If I take the spark plug out and turn the key it turns over normally. The battery is good and every thing I've learned by googling and watching youtube videos says to adjust the valves. I've adjusted both valves to .004 as one youtuber suggests, and to .004 intake and .006 exhaust as others say ). I've tried both settings several times and keep having the same problem when I put the spark plug back in and turn the key.

both the intake and exhaust enter and exit near the top of the valve housing so I'm not certain which valve is which. One video I watched which was for riding mowers in general and not Troybilt Pony said the exhaust valve is the one that is on top and the intake valve the bottom one - is this correct?

I do notice a sulfur / rotten egg smell when I try to start it - does this help diagnose anything ?

I'm at a loss - any suggestions on what I might be doing wrong or whether it might be a problem other than the valves like the solenoid or something would be greatly appreciated. :confused2:

I work on my own cars when they need repaired (have done head gaskets, brakes, etc.) but this is the first time I've tried to adjust valves.
 
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Briggs vertical are intake on top. All of them.

You watched the vids and turned the flywheel so they were at the right position when you made the adjustments ??
 

ILENGINE

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Briggs single cylinder vertical OHV engine use a crossflow head, Which means the intake is on the bottom. If you are sure you have the valves adjusted correctly, then while turning the flywheel slowly watch for the intake valve/ bottom to bump off seat slightly just before TDC compression. You could have a situation where the flyweight on the camshaft is broken and the compression release no longer works, and will require replacing the camshaft.
 

Scrubcadet10

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I always thought you were supposed to set them 4 to 4? I'm sure I'm wrong though, And do you think it could be the compression release on the cam? More thane likely not, but sometimes the spring will come off and the CR won't work... But it does sound like something in the head/ valve mechanism.....:smile:
ILENGINE, it shouldn't require replacing the entire cam, just the comp. release. It is riveted in on most engines. But in some cases people just go ahead on put a new cam in, it's a lot simpler.
 

ILENGINE

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I did 4 over the summer this year. In all cases the decompression mechanism was in about 10 pieces laying in the sump of the engine. On some engines the valve clearances are .004-.006 for both on others it is .004-.006 for intake and .005-.007 for exhaust. So most people will just say 5 and 5.

Briggs doesn't normally offer just the decompression mechanism as a replacement part.
 

Tinkerer200

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"ILENGINE, it shouldn't require replacing the entire cam, just the comp. release. It is riveted in on most engines."

Let me know where to get the parts.

Walt Conner
 

ILENGINE

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"ILENGINE, it shouldn't require replacing the entire cam, just the comp. release. It is riveted in on most engines."

Let me know where to get the parts.

Walt Conner

Walt is that a statement or a question. I am slightly confused by your post.
 

Scrubcadet10

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I use pro parts direct.com, they have the ACR but need to call for avaliabilty .... I know cub cadet (kohler) makes the ACR for their cam.

I AM JUST GOING OFF OF WHAT I HAVE SEEN ON MOST LAWNMOWERS Cam wise.
 
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