Small Engines (Lawn Mowers, etc.): MURRY lawn mower, riding lawn mower, question pool

Question
QUESTION: I have  a 16.5 hp murry riding lawn mower with a B/S engine model 31c707 type 0175E1 code 031008ZE. The mower is about 4 years old. the carburetor is a Nikki. The problem is the motor tends to miss once the engine has ran for about 10 minutes. The miss is believed to be a function of mower motion and turning hard to the left aggravate the miss. The engine does not die and will recover in time. It is not associated with load but more motion included roughness of the ground. The carb. has a fuel solenoid and when the motor is pulling down pecking on the carb. or solenoid causes the motor to pick up in rpm. I have removed the carb. bowl and dumped the fuel. the carb was clean. I have changed the fuel filter,spark plug and air cleaner with no change. I have removed the solenoid and with it plugged in it is solid until it gets hot and the the plunger goes in and out with motion of the solenoid or tapping on it lightly. I suspect the solenoid but dealers say if it clicks and the engine runs it not the solenoid. I am reluctant to spend $50 on anew solenoid based on their input. My questions are (1} what are you thoughts (2) do you Know of similar problems with this solenoid (3) can you tell me where I might get a solenoid at a more reasonable price that would make it more desirable to take a shot at replacing.          Thank You Glen

ANSWER: Hello Glen:

Sorry for the Delay. This Question was Located in the Question Pool and I can Only Answer Questions from the Question Pool when I am Not Answering Questions here or at the Other Site I Answer Questions at. To Check the Carburetor Solenoid: The Following is a Basic Instruction File I made for Checking the Carburetor Solenoid. Any Input is Appreciated. **Check for Current/Voltage (10.5 VDC Minimum) to the Carburetor Shut Off Solenoid. If the Carburetor Shut Off Solenoid has Current, then On Some Solenoids you can Remove the Needle and Replace the Solenoid to Test them. ****PLEASE DO NOT OPERATE THE MOWER WITH THE SOLENOID BYPASSED IN THIS MANNER. THIS IS "ONLY" FOR TESTING.**** For Others, Remove the Carburetor Solenoid and Go to the Hardware Store. Purchase a Bolt of the Same Diameter and Threads.It Needs to be 1/2" to 3/4" Long for the Horizontal Mount Solenoids and 1/4" Long for the Vertical Mount Solenoids. Put this Bolt in Place of the Solenoid. If this Corrects the Engine Problem, then Replace the Solenoid. ***NOTE: THIS IS FOR CHECKING THE SOLENOID ONLY I NEVER SUGGEST YOU OPERATE THE ENGINE WITH THE SOLENOID OUT OF THE CARBURETOR EXCEPT FOR TESTING PURPOSES*** Sometimes the Plunger is Moving, Just Not Far Enough to Allow the Gas to Enter the Jet.**  I Also Suggest you Remove the Blower Housing and Check the Condition of the Shut Off Wire for the Coil and the Coil Lead to the Plug. Make Sure they are in Good Condition  and are Not Grounding when Moved Around. 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. Thanks.

Respectfully

John

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

QUESTION: Dear John
Thank You for your valuable input. I am a mechinical engineer and I should have thought of this myself knowing how the selnoid works. I did the screw in the carb and everything now works fine. I am considering putting a manual inline gas cutoff valve in the inlet line and turning it off and letting the engine run untill the gas is depleted. Whats your thoughts? Should I decide to just eliminate the inline valve what are the ramications?
         I truly appreciate your response. It really helped me. Thanks again. Peace be with you and yours    
         Glen

Answer
Hello Glen:

The Carburetor Solenoids Purpose is to Prevent Engine Backfire and  Run On by Shutting Off the Gas Flow at the Carburetor Jet. This Prevents Any Gas from Entering the Engine During the Shut Down Process. I Cannot Suggest you Leave the Solenoid Out of the Carburetor; However, I have Several Engines that are Now Missing said Solenoid and All my Equipment have Manual Cutoff Valves. Till Next Time. May All Your Mechanical Problems be SMALL ONES and May the All Mighty Bless You and Yours. Thanks Again.

Best Wishes and Good Luck

Respectfully

John