# Craftsman GT 5000 Engine Problem & Puzzle



## Urick (Mar 26, 2009)

This is a year 2004 Craftsman GT 5000 and it has a 446777, type 0244-E1 engine; I previously posted a problem with this tractor having a starting problem where the starter would not turn engine without help from a boost. Regardless, this problem was helped by going to synthetic oil and I have used the 48" grass mower since without too much trouble starting. It is/was used to more a flat 1 acre lot once a week during the mowing months here in Kentucky. It has about 3 hours on the most recent oil change, 5-30W Pennzoil synthetic oil, new air filter etc.

Now to the current problem: This weekend I was mowing my acre flat yard on a bright 85*F day when about half way through, the motor suddenly quit without warning. No rattles, no bangs or other audible indications of a problem. I tried restarting and it would turn easily but would not start. I dismounted and examined the engine oil, fuel and plug wires etc.; nothing of note was discovered so I tried starting a few more times and it did start although running rough and without the mower engaged. I tried engaging mower and it stalled. I got it started again and managed to limp into the garage when it died at the door. Again motor would turn with ease but would not start. Oil was clean, connections tight but would not start. I pushed into the garage and checked the mower deck clutch and belts. All was well. I had just serviced the deck and installed a new drive belt two sessions previously. Both spark plugs showed fire outside the engine. Gas was entering the carburetor at the fuel line orifice.

I decided to remove the valve covers and examine the valves. I started with the #1 cylinder (the one with the fuel pump hose connection on the cover). I turned the engine by hand using the fan atop the engine and the valves operated in a normal fashion (I have not and did not measure the clearance on the valves). I moved to the opposite side #2 cylinder and removed the valve cover.

What I saw dumbfounded me! The exhaust valve's steel push rod was absent! The rocker arm assembly, valve spring and valve were there but no push rod. The intake valve and aluminum push rod were in place. There were no indications of trauma around the interior of the cavity; no metallic shavings, no dings or gouges. I continued by removing the cylinder head and examining the cylinder wall was slick with no roughness, valves were seated and by compressing the springs they moved freely. The piston top and surrounding head environment showed blackened soot/ash but not in excess. I am not sure from here how to proceed.

Question 1

Where did the push rod go? Is it possible it never was present? Could this engine run 5 1/2 years without the push rod on the exhaust valve? If so why did it suddenly quit working? Did the valve clearances wear to the point the push rod was dislodged from its socket?

Question 2

Would installing a push rod, assembling and setting the valve clearances 
allow the engine to start and solve problem? I really don't want to remove the engine from the tractor frame. What dangers lurk if the push rod actually made it to the sump below?

Question 3

What do you think? Ideas are welcome. Are there other courses of actions besides a new engine, total overhaul or new tractor? 

Thanks for any help,

Urick


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## Wrench97 (May 10, 2008)

1st> there's flat ground in Kentucky?:grin:

2nd > if the push rod is not up in the head it has to be in the crankcase, your going to have to dig in deeper and check the cam and lifter/cam follower for damage as well as locate the push rod whole or in pieces, there's no way you've been running it for 5+ years with one missing.


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## Urick (Mar 26, 2009)

Yep, along the rivers in the East Ky. and in West it's all flat.

There seems to a dearth of ideas so I suppose I have to bite the bullet and tear the beast down. I have some mechanical abilities but I would like to have a removal and tear down procedure for the 446777 Briggs engine. Are there such animals available on the net?


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## Wrench97 (May 10, 2008)

Yep there sure is> http://www.briggsandstratton.com/maint_repair/manual_and_more/


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## Urick (Mar 26, 2009)

EPILOG

Well, I decided to try another push rod in for the one missing. As I suspected after turning engine by hand, #1 cylinder valves worked and #2 didn't after a half rotation. The locknuts and push rod seat was tight and had not loosened. And I didn't change when I replaced the missing exhaust rod. The gap measured .125" with the intake totally valve open, which suppose is why the rod went missing. Regardless, this set the stage for exploratory surgery which proceeded normally and when the sump half of the engine was removed it revealed 90* of the camshaft gear was broken and nearby was the pushrod bent in the shape of a horseshoe. I ordered the camshaft which includes the gear and a gasket kit for the engine. I figured it was cheap insurance to replace the effected seals. Cam was replaced and seals were installed quickly. Engine was duely mounted to chassis and I adjusted the valves to .05". After setting the governor I was ready to give it a start. After several years of expletive filled starting sessions, I full well expected problematic starting which had plagued this motor since it came from the local Sears store. I had thought that the Twin V was a poor design, because as a user, it failed a major criteria of a good machine, easy to start. Regardless the engine whizzed and sputtered and blasted off on the first attempt!!!! I was dumbfounded. I reattached the mower deck, which is a major pain but that's another story, and decided to take the GT5000 out for a spin. And what a spin it was!!! At half gas feed lever position I cut 4-5" grass to 3" with great ease, power flowed through the machine that I had never seen before. After all the badmouthing on my part of how sorry the engine was it was incredible the change. Smooth running and easily started. I admit it I was wrong about the engine being a bad design. It actually is an elegant design. Upon examining the internals of this V twin I developed and appreciation of its elements and upon using a properly adjusted and tuned engine it has great power to accomplish its tasks.

The moral to this story is simple: If you depend on a machine being in tune and correctly configured from the factory/store, you most likely will be disappointed. If your Twin V engine is hard to start either adjust the valves yourself or have someone do it!


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## Wrench97 (May 10, 2008)

Should I take back the "there's no way you've been running it for 5+ years with one missing." Statement?:1angel:

Good job I've seen a lot guys tear them down, few get them back together and running on the first attempt:4-clap::4-clap:


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