Small Engines (Lawn Mowers, etc.): air compressor backpressure?!?!?, flapper valve, exhaust stroke

Question
QUESTION: Hello,
this is an old post getting back to you.  I thought I had a wiring issue with a Sears Air compressor Model 919.176830 and have today discovered something totally different.  Here's what happened:
I started it by turning the switch on and it fed the tank to 35 psi where it started laboring the motor (I turn it off b/c it will eventually trip breaker)
I purposely didn't;t bleed off the the head and tried to turn it by hand at the exact moments the motor starts struggling and there is definitely a breathing problem there at that moment.
I remove discharge pipe (3/4") and no pressure.
I remove check valve and reconnect discharge to it and run motor and everything works fine (of course it is not filling tank it is just blowing off to the side through check valve.
So I am left with my only guess going to the intake. This thing seems to exhale fine and the switches seem to operate, but the wheel does not want to turn after 35 psi...

Question...what should I do now?

Thank you so much for helping us DIY out..I live on an extremely small budget and your professional advice can make or break that budget and my day!


ANSWER: Hello Ryan:

The Back Pressure is Usually caused by a Bad Check Valve (not the Relief Valve) or a Bad One Way Valve (Flapper). When the Piston takes an Intake Stroke it Pulls Fresh Air in and then Pushes this Air Out into the Tank (past the Flapper) During the Exhaust Stroke. If the One Way Valve (Flapper) is Bad, then All the Tank Pressure is Allowed to Constantly be on the Compressor Head and Each Intake Stroke has Pressure Due to the Tank Pressure Not being Held Off the Piston by the One Way Valve (Flapper). In the Breakdown of the Compressor the One Way Valve (Flapper)is Called a Exhaust Flapper Valve (#68). Remove the Compressor Head and Check the Flappers. If they are Not Seating Properly, then you will have the Problem you Described. To View a Breakdown of this Unit Go to this Site Addy, http://www.searspartsdirect.com/partsdirect/index.action and Enter the Model Numbers and Click Search. From this Page you can View Diagrams and Parts Lists for you Equipment Using the "View Sub Components" Section Near the Bottom Left. If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Ratings and Comments are Greatly Appreciated. Thanks.

Respectfully

John

---------- FOLLOW-UP ----------

QUESTION: thanks so much John and believe me- not a day goes by where the almighty hasn't blessed me in a hundred ways.  We are very thankful to be living such extravagant lifestyles here in the USA and are doing everything we can to reach out and spread the word and help to those in my community far from god.  I belong to www.moviechurch.com and we are doing great things here locally.

I took the head off and everything mechanical seems in great working order here on this machine.  I even replaced the check valve this week and still the same problem persists.  I have a struggling motor after 35 psi.  What do you think i can do next, short of bringing the motor to a shop for testing.  Remember I am trying to be as cheap as possible so there is money to actually purchase the parts I need.

Can't thank you enough for the help,
Ryan

Answer
Hello Again Ryan:

Thanks for the Site Addy. I will Visit it and See what it is All About. Since you are Sure the Everything is Good with the Compressor, then the Starter Capacitor in the Electric Motor is the Cause for this Problem. If the Electric Motors Starter Compositor is Bad, then this Problem will Occur. It is Rare for this to Happen, but it does on Occasion. If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. Once Again May the All Mighty Bless You and Yours. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John