Craftsman 4 stroke 316.711700

[VoiceofDoom]

I've seen this discussed before but no fixes. There's oil leaking from the breather tube into the air intake housing. There's a little flap valve that the hose hooks to. Oil leaks out anytime it's upright to start (not running). In all the engine diagrams I've seen the oil breather tube shown and the air cleaner assembly also. But, you can see the little X on the back of the cleaner assembly but not the flap valve. Does anyone know what the problem is or the fix. Any help would be appreciated.

 

[sgkent]

are you talking about the fuel pump diaphragm in the carb? If so that is a carb part. Some carbs have rebuild kits, some do not. Some of the ones that do they cost as much as a new carb, and they do go bad every few years.

 

[StarTech]

Every one of these AC3/AC4 engines does this when the engine is worn out. Just replace the whole. Btw the breather is considered part of the air cleaner so a new air cleaner might work but I doubt it.

 

[sgkent]

so there is too much blowby? Do these engines carry crankcase oil? if so is it clean and fresh? Another reason for excessive blowby on these small outdoor engines can be the exhaust screen (spark arrester) gets carboned up and that creates excessive back pressure which ends up being blown past the rings and out the breather.

 

[VoiceofDoom]

This was used one time so I don't think it's used up. The oil leaks out without the engine even running. It's not part of the carburetor. The breather tube is connected to the backside of the air cleaner next to the carb with what looks a rubber valve to regulate back pressure the tube is listed in the engine diagram but not the valve. I can understand if the engine is running there might be blow back but it's just leaking out when the Wacker is placed on its side as if to start it.

 

[StarTech]

First it has been only used once it should be under warranty and you should be letting the store that sold it and the OEM handle the problem.

Those PCV valves (usually mounted in the air cleaner) that I seen used on these usually have a spring with a disk to prevents this unless the engine is running so it is mostly defective and the air cleaner assy has to be replaced. The 753-06796 is dirt cheap at $5-$6. But if they changed the design and tried to go with a rubber duck bill valve that could be the problem as they apparently didn't update the IPL. Besides a rubber duck bill valve would be an extremely poor choice in this area.

BTW these MTD 4 cycle trimmer engines are not meant to started, ran, or storage in position than upright. Most of my customer are losing their trimmer of this design doing edging with the engine of its side. It is, in my opinion, one of the worst designs out there. Shindaiwa make a much better version and Stihl 4mix has the best design. The Stihl 4mix is well worth the premium price tag.

 

[VoiceofDoom]

Thank you, that's the most pertinent information so far. This was given to me by my brother. It's several years old and I'm going by his word. It does look brand new though. Just as a micky mouse fix I was wondering if I block the breather tube and drilled a small hole in the oil filter plug. Now as soon as you pick yourself up off the floor and didn't hurt yourself from laughing. This wouldn't be what a professional would do but a half ass attempt to get it working for me.

 

[VoiceofDoom]

Thank you, that's the most pertinent information so far. This was given to me by my brother. It's several years old and I'm going by his word. It does look brand new though. Just as a micky mouse fix I was wondering if I block the breather tube and drilled a small hole in the oil filter plug. Now as soon as you pick yourself up off the floor and didn't hurt yourself from laughing. This wouldn't be what a professional would do but a half ass attempt to get it working for me.

And I'm always looking for ways to be half assed instead of a full ass.

 

[sgkent]

I'd hang it upside down like a stuck pig and let the oil drain out. Find something that needs oil and use it. Then add oil anytime you need to weed wack.

 

[VoiceofDoom]

Well guys, I really appreciate all your help. However, no one mentioned operator error. I read the manual and saw fill to the 1st thread. Bring a male and figuring I knew what I was doing I did. The only problem was I failed to notice it was while the Wacker was horizontal while I filled it vertical. That's why all the oil was draining out. I'm not sure but I'm guessing the other people who were having the same problem did the same thing. I apologize for waisting your time. Though a good laugh at my expense may have been worth it.