Craftsman T1200 - Won’t Start

slomo

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Compression is at 150
That is high. Might need to de-carbon the cylinder and valves per your engine manual. Briggs motors are mostly 8:1 compression. Definitely inspect the valve lash or lack of.
Battery is at 12.26v and is new,
Tells me your battery might not be charging and or definitely needs charged. At rest 12.6 is fully charged. Take battery to any auto parts store. They will check for free. Might have a weak cell pulling the others down.
 

Matnetik

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That is high. Might need to de-carbon the cylinder and valves per your engine manual. Briggs motors are mostly 8:1 compression. Definitely inspect the valve lash or lack of.

Tells me your battery might not be charging and or definitely needs charged. At rest 12.6 is fully charged. Take battery to any auto parts store. They will check for free. Might have a weak cell pulling the others down.
Yeah battery was just low from trying to crank it, I charged it and it’s good to go now - just won’t turn over or run - I suppose the next step is opening the valve cover and inspecting
 

slomo

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Yeah battery was just low from trying to crank it, I charged it and it’s good to go now - just won’t turn over or run - I suppose the next step is opening the valve cover and inspecting
Take the battery and have it LOAD TESTED. Charging a battery doesn't tell the whole picture. Once you hit the key, a dead cell will make the entire battery fall on it's face delivering less than required current.

Once you confirm you have a good battery, then attack carbs and other mower parts.
 

slomo

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Brand new carb (also took it out, completely disassembled, cleaned and rebuilt)
OEM carb or Chinese amazon ebay specials?
Fuel Solenoid is functional and clicks when the key is turned (also disassembled and cleaned)
While you had it out, did you watch the plunger move when you hit the key on and off?
New NGK spark plug
Do you have spark from the coil? So now 2 plugs and no fire? Just read you claim to have spark.
Added fuel cutoff valve and new fuel filter
Good man now use them.
Battery is less than a year old and fully charged
Already covered this. Needs tested and confirmed good.
20A fuse is good to go
How was it checked? Visually or a meter? Sometimes they can look good and be blown.
 

Matnetik

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OEM carb, checked spark with the spark plug tester. Checked fuse with the fuse tester. Will take the battery to have it load tested but it’s only about a year old, could still be an issue!

I just popped off the valve cover and one of the rockers was loose and I could spin it around. Here are a few pictures, I wonder how much deeper I need to dig into this
 

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slomo

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I did forget to mention I tested for spark and can confirm it’s getting it via plug tester
I tried gas in the air intake as well as starter fluid with no luck
So you have spark and she won't fire off with starting fluid? A-maz-in. Flywheel key is good. 150psi means you need to pull the valve cover. Beat me to it LOL. Nice pic. Yeah you have issues. Now investigate WHY the rocker came off. Never ran valve lash? Bent push rods?
 

slomo

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Does your engine have a valve stem cap? If so find it and put it back on. Then set the lash.
 

slomo

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Will take the battery to have it load tested but it’s only about a year old, could still be an issue!
Fix the valve issue. If you still have issues have the battery tested.
 

Matnetik

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Does your engine have a valve stem cap? If so find it and put it back on. Then set the lash.
And we have success! Cranked right over after fixing the rocker, running a bit sloppy but I’m sure it’s from all the fuel in the cylinder, tomorrow I’ll run some seafoam through it and let it run for a while and see where we’re at- thanks for all the help and will report back, learned a ton about the mower from this process
 
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