# Craftsman 24hp bent pushrod & stuck valve



## 84HyperZ (Jul 28, 2010)

model# 445677-0827E1 w/ 45.8hrs --- little brother was given the mower with complaints of intermittent starting issues that i have yet to experience. Cleaned the carb and ran fine till a backfire and the first bent pushrod. Right bank lower side. Replaced the pushrod with new and bent that one by turning flywheel by hand when i realized the valve was stuck. My two questions are 1) what could have caused this issue & 2) how difficult of a job to replace being that i am somewhat mechanically inclined, or would i be better off taking out for repairs?


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## 30yearTech (Sep 14, 2006)

Usual cause of a stuck valve is overheating from plugged cooling system, low oil or contaminated / dirty oil.

You need to determine if the valve guide came loose in the head, or if the valve is just seized in the valve guide. If the valve guide is loose, then you will need to replace the cylinder head. In either case you will need to pull the head and either free up the valve or replace it.


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## light mechanic (Jul 18, 2008)

30yearTech, that is one of those with the plastic intake manifold I think, they love to suck dust into the engine and die an early life.
84HyperZ, might be better to look for another engine, good luck


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## justin3 (Apr 10, 2007)

More then likely the valve guide came out, very common on these V-twin engines. I really don't think you need a new motor like Light mechanic said, a new cylinder head assembily is only around $90 and thats alot cheaper then a replacement engine.


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## 84HyperZ (Jul 28, 2010)

i started disassembly this evening (er yesterday). Light mechanic you are correct in that it does have the plastic intake. Not sure if it's helpful or not but when i first discovered the stuck valve, i managed to forcefully by hand compress the valve open. Been about a month now and valve is closed again. I may just look into replacing the head. But until that time would you guys be able to tell me the size of the exhaust screws? Torx larger than t45 smaller than t47.


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## light mechanic (Jul 18, 2008)

84HyperZ, I am not sure on the size of that bolt but will check and get back with you, if that valve will move with a light tap I would not remove the head, put it back together bet it will work fine, just move it a few times, if it is just for you, you can always take it apart again, if is for a customer you would not want a come back, Light Mechanic


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## 440s-4ever (Feb 23, 2010)

First figure out if the guide is stuck to the valve or not. 

If the guide is still firm in the head and it's just a sticky valve, then remove the valve and chuck it in a drill. Spin it to see if it's bent or not. If it's bent, replace it. 

If it's not bent look really close at the guide. You need to figure out what's resisting movement. 

If you're on the cheap and the valve to guide surfaces need dressed you can either use fine emory cloth on the valve while it's mounted in the drill. Or you can coat the stem with lapping compound and spin it in the guide, but be one thousand percent sure you remove all the lapping compound afterward. A thou makes all the difference in the world so don't go crazy removing material. Probably more like 20 turns than 200. 

Sometimes while they're unseating guides can get cocked or ovaled a little and grab the valve. As this head is prone to losing the guide, be certain that you're not on the edge of guide failure. If you can tap the guide out and it's still got decent fit, just reinstall with permanent loctite and be sure the valve slides freely. Should be good to go. 

The downside to loose guide fit is oil consumption, especially on startup. If you can live with that then you can probably live with loose guide-to-valve clearances. There is very little risk to the valve. Tight fit is when it gets risky. 

Good luck


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## 84HyperZ (Jul 28, 2010)

Started tinkering first thing this morning and first off allow me to correct myself on which valve was stuck.... intake not exhaust... sorry. Secondly i don't know why it's the simple things that are always overlooked first. Shined a light down the intake port and to my surprise... carbon... loads of it, both banks. Little bit of penetrating lube and few light taps of a hammer against a screw driver handle so as not to scar the valve rod and got it worked loose. I still will be removing both heads for further cleaning. Thanks guys! Also what are the torque specs for the head bolts?


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## 30yearTech (Sep 14, 2006)

84HyperZ said:


> Also what are the torque specs for the head bolts?


Here is a link to a service manual. All the torque and sequence info will be available in the manual.

http://www.mymowerparts.com/pdf/Bri...73521 Twin Cylinder OHV BRIGGS & STRATTON.pdf

Best of Luck... :thumbsup:


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## 30yearTech (Sep 14, 2006)

light mechanic said:


> 30yearTech, that is one of those with the plastic intake manifold I think, they love to suck dust into the engine and die an early life.
> 84HyperZ, might be better to look for another engine, good luck


I don't see this situation in the field as much as it is reported, and the plastic intake has nothing to do with it. This is more a result of a bad seal on the air filter element, regardless if there was dirt ingestion this generally will not cause a valve to seize in the guide, but rather cause wear and increase oil consumption. I think it's a little premature to determine that engine replacement is needed based on the information that has been presented so far.


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## 84HyperZ (Jul 28, 2010)

got all re-assembled and buttoned up. valve is no longer sticking but won't start. getting fuel and spark. compression is 120 and 145. guess i will pull the carb and rebuild. oh and btw my eyes lied to me... exhaust screws were hex heads


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## light mechanic (Jul 18, 2008)

check to make sure that the fuel valve is working at the bottom of the carb, it should click when you turn on the switch, might remove it and make sure that it is moving, drop a little fuel down the intake to see if it will fire up, if it has been setting bet it is the fuel shut off valve, good luck, Light Mechanic


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