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Motoman (newbie) here to tell a tale of woe and redemption in the Cascades of WA. It all started with a new Craftsman 48" /Intek mowing the 1 1/2acres of grass of my new digs. All was fine the first year. Summer of year 2 one cylinder went away. Compression good. Baffled. Finally pulled right valve cover to discover exhaust rocker not actuating. ***? Took engine apart and found an amazing sight.

The exhaust lobe on the camshaft had been ground "round" like a journal-no eccentric to lift the valve train. Plulled the head and found the exhaust guide was "pushed" upward to where the rocker coulld not work. The slow interference had gradually ground the lobe off. No noise . No drop in power until the cylinder went away. "This can't happen to a new Sears appliance, can it" Oh yes brother , welcome to the shadowy world of lawn tractors. "But the owners manual...? I did everything right...?

Remember the offer of a service contract at Sears, and the funny look the sales dude gave you when you said "no?" Hmm. And all the neighbors who have these things that won't start or don't work...?

I don't even remember whether warranty was up. Think so when I went straight to Briggs in WI. Very hard bunker to penetrate. Finally I got a mailing address and sent the cam there. To my surprise I received two new heads and gasket set a week later. I suspect they had seen this before. Stubborn type that I am I repositioned the problem guide and ran the tractor a while. Pulled the cover and could see the guide was again on the move. New head fixed things, but nagging thought persisted: what next ?

For fun I took the head's external temperature and found it in the 400deg F to 500deg F range. That didn't really prove anything. The nagging thought: Assembly of aluminum with pressings is done at around 400 deg F! Is this engine a time bomb? How hot does it run inside? If the tolerances are off a little stuff will begin to come apart (OD of guide low side, bore for guide in head is high side , etc.)

I had an old mechanical oil pressure gage, and I bought an oil temp gage . With these in place I deet ermined that the

Have seen more than one cam lobe worn round on briggs and stratton single and twins in my repair shop over the years, The head temps may be high but remember that the exhaust manifold is right under the head and may be getting some heat off of it messing up your exact temp readings.

ILENGINE said:

Have seen more than one cam lobe worn round on briggs and stratton single and twins in my repair shop over the years, The head temps may be high but remember that the exhaust manifold is right under the head and may be getting some heat off of it messing up your exact temp readings.

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Dear ILENGINE, I suspected I was not alone, but (of course) Briggs was silent , but nice gesture to send me parts. The rest of story would include finding operating oil temp @300 deg F and putting on the gages and cooler. I have stopped the discussion waiting on the site admin to explain why I cannot extend the text. I am a newbie, and if too wordy for this site the installations will have to be chopped up into segments. Regards, Motoman

motoman said:

Dear ILENGINE, I suspected I was not alone, but (of course) Briggs was silent , but nice gesture to send me parts. The rest of story would include finding operating oil temp @300 deg F and putting on the gages and cooler. I have stopped the discussion waiting on the site admin to explain why I cannot extend the text. I am a newbie, and if too wordy for this site the installations will have to be chopped up into segments. Regards, Motoman

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I have the same problem and heard of many people complaining about it. Black Bart is the latest victim. See "this site has a glitch" Very annoying, especially if you use a long quote.
Some have mentioned it's a browser problem, other than that it's not been addressed. I've decided to live with it and use the up-down buttons to navigate around the problem.
I for one think your post is very informative and one of the more useful........less emotional posts, to date. I am however very dissappointed in your inability to get some photos to compliment your acheivement. Your technical abilities are comendable, posting a few pictures is........well you could train a chimp to do it. RB

RobertBrown said:

I have the same problem and heard of many people complaining about it. Black Bart is the latest victim. See "this site has a glitch" Very annoying, especially if you use a long quote.
Some have mentioned it's a browser problem, other than that it's not been addressed. I've decided to live with it and use the up-down buttons to navigate around the problem.
I for one think your post is very informative and one of the more useful........less emotional posts, to date. I am however very dissappointed in your inability to get some photos to compliment your acheivement. Your technical abilities are comendable, posting a few pictures is........well you could train a chimp to do it. RB

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RB Since some are interested I will go with installments...I, II etc. I am the chimp trying to evolve into upright stance. The wife is searching for a disc for an older camera we have. Patience. Motoman

This one of the many problems I see if you run propane, valve guides and valve seat trouble.

supertech, Just noticed you responded to my old thread. Have you measured the head temp of propane fueled or gas fueled. Some here are trying to develop expected "normal" temperatures of the air cooled units so that the many stating "overheat" will have a way to validate it or not.