QuestionQUESTION: I have a John Deere 445 that was running fine all winter long. It is I believe a 1995 with 596 hours on it. I checked the plugs and am getting spark from both of them. All sensors are working fine and the fuses are fine. It turns over fine but will not fire up. Having browsed some articles, I am wondering if I have the dreaded nylon cam problem. The reason I am thinking it is a possibility is the fuel pump is working fine, however, gasoline in filing up in the carburetor and overflowing. Could this mean that the valves are not opening? Or maybe some older gasoline has gummed something up in the carb? If that was the case I do not understand the wet plugs. I also tried spraying a little starter fluid in the cylinders and still no indication of trying to fire. Should my next step be to take off the rocker covers and see if the rods are moving? Thank you for any suggestions? Gary
ANSWER: Hello Gary:
>>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.
>>From your Description it Sounds like the Carburetor Float Needle Valve is Not Closing Correctly and is Flooding the Engine. **The Wet Plugs are Due to Too Much Gas Entering the Cylinders and Flooding the Spark Plugs so they cannot Ignite the Gas.** Too much Gas will Not Ignite inside the Cylinders.
>>Soak and Clean the Carburetor.
>>You can View a Breakdown/IPL of the Engine and Mower at this Site Addy, http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.H and Enter the Model Numbers 445 and Click Find. Then Select your Model from the Search Results Area. Then Select the Sectional File. Then Select the Section of the Mower you Wish to View Online. *You can Drag the View Windows for Better Viewing.*
>>The Following is a Basic File I Made for Cleaning Carburetors. Any Input is Appreciated. Even though the Carburetor Looks Clean, the Internal Passages May be Restricted with Varnish that Gas Causes to Build Up over Time.
>>Spray Cleaners Remove this Varnish in Layers, so Soaking is the Only Sure Way to Remove ALL this Varnish.
>>I have Found that Most People can Use a Breakdown/IPL and Disassemble the Carburetor Enough for Proper Cleaning.
>>You Only have to Remove the Bowl (if Applicable), Float Pin (if Applicable), Float (if Applicable), Needle Valve.
Remove Any Adjustment Screws that Go Into the Carburetor Body. The Welch Plugs Do Not have to be Removed.
>>If you are Able to Remove and Disassemble the Carburetor and Keep the Gaskets Intact, then Usually these Gaskets can be Reused. The Only Parts you May Need to Replace is the Needle Valve.
>>The Float Needle Usually is Not Replaced Unless it is Not Operating Properly (the gas flow not shutting off and the carburetor is Flooding). Do Not Remove the Main Nozzle. This is a Pressed Fit and Removal is Not Required for Cleaning. Soaking and Blowing the Carburetor Out After Soaking will Clean the Nozzle.
>>Once Disassembled, then Soak the Carburetor Body and Parts in a 1 Gallon Can of Gunk Carburetor Cleaner Overnight. The Can has a Parts Tray Inside it for the Small Parts.
>>Once the Carburetor and Parts are in the Cleaner, you can Replace the Lid for Safety and to Prevent Accidental Spillage. Then Blow Out the Passages with Compressed Air.
>>***(Do Not Use High Pressure Air for the Zama Carburetors, they have Check Valves for the Primer and these are Usually Blown Out of the Carburetor if Not Careful. Allow the Zama Carburetor to Set on a Drip Pan and Dry)***.
>>****All the Carburetor Adjustments are the Same for Lawn Mower and Trimmers. There are Several Location for the Air Mixture Screws. The Idle Air Mixture Screws are Usually Located at the Top of the Carburetor Bowl and the Top of the Carburetor Body.****
>>If the Main Air and Idle Air Mixture Screws are Side by Side on the Side of the Carburetor, then the Idle Air is Nearest the Engine. The Main Jet Air Mixture Screw is Located in the Bottom of the Carburetor Bowl or Beside the Idle Air Screw on the Side of the Carburetor Body.
>>Some of the Older Model Carburetors have the Main Jet Mixture Screw Straight in from the Top of the Carburetor Body (this is Rare anymore). If you have Cleaned the Carburetor (Disassembled and Soaked Overnight in Carburetor Cleaner (I Use Gunk). Then Blow Out the Passages with Compressed Air and Install a New Kit if Required. Now Setting the Air Mixture Screws:
>>****Turn the Idle Air and Main Air Mixture Screws In Until SNUG **Do Not Jam** Then Reverse Both Screws 1 1/2 Turns. Holding the Throttle Full Open, Start the Engine. Turn the Main Air Mixture Screw Clockwise Until Proper Revs are Obtained. Occasionally you May have to Turn this Counter Clockwise to Achieve the Proper Revs. Now Allow the Engine to Idle. Set the Engine Idle Screw (Not Idle Air) so the Engine will Stay Running if Required. Now Set the Idle Air Mixture Screw so there is No Hesitation when Throttling from Idle to Full Throttle. Reset the Engine Idle if Required.****
>>If This Carburetor has a Single Air Adjustment (Except Tank Mounted 9200 and 100900 Engine Model Carburetors), Use the Section Above that Pertains to Full Throttle RPM Air Mixture Screw and then Adjust the Screw if Required to Eliminate Any Hesitation when Throttling from Idle to Full Throttle.
>>For the 9200 Model Tank Mounted Carburetor Adjust the Air Mixture Screw Full In, then Reverse 1 1/2 Turns. Set the Throttle Lever to Full Throttle and Start the Engine.
>>Now Carefully Use 1 Finger and Open the Throttle Plate and Over Rev the Engine Slightly. If the Engine Over Revs and Does Not Struggle to Over Rev, then the Carburetor is Set. If the Engine Struggles to Over Rev, then Turn the Adjustment Screw In 1/4 Turn and Repeat the Over Rev Test.
>>If you Adjust to 1/2 Turns In and the Engine Still Struggles to Over Rev, then Return the Adjustment Screw to 1 1/2 Turns Out from Snug and Turn the Screw Out 1/4 Turn. Do the Over Rev Test. Continue this Process Until you have the Engine Over Revving without Struggle.
>>By Adjusting the Carburetor on this Style Carburetor Until the Engine Over Revs without Struggle, you have Adjusted the Air Mixture to the Best Possible Setting.
>>This file was Intended to Give you the Basic Carburetor Cleaning Instructions and May Not Reflect Your Carburetor Components.
>>If you have Questions, Please Ask. The links above Provide Good Directions on Cleaning the Carburetor. Make sure you use an Compressed Air to Blow through all the Carburetor Passages to make sure they are Clear.
>>1- http://www.repairfaq.org/samnew/lmfaq/lmclctc.htm
>>2- http://www.cpdonline.com/692509.pdf .
>>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. Be Safe and Happy. Thanks.
Good Luck
Respectfully
John
PS: I am Allowed to Answer 5 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
---------- FOLLOW-UP ----------
QUESTION: John, I have been waiting for you to be freed up so that I could follow up. I appreciate all your help which led me to find an unusual solution to my problem. Again, I was getting gas and spark but the carb was filing up with gas. I took the carb to my local Deere dealer to check out the fuel return etc. They tested it and said it was working and the problem was likely an electronic part (board that controls the fuel injection system) on the tractor. The bad news was, according to them, was that that part cost about $1100. I didn't buy that and decided I would still try and do it myself. With a friend, I again took off the valve cover gaskets and found the problem. Both intact push rods were off of the rockers. They were not bent and in fine shape and we had no idea how that happened. The problem all started when I turned off my tractor after moving some snow and a week later it would not start. No backfire that I remember or anything that would have given me a clue to this weird scenario. We put the rods back in place and set the the proper gaps. They really were not off that much. None of my buddies can figure out how that happened. Put everything back together, changed oil and it is running like a charm. Hopefully this may help someone in the future, however, I do not think crazy stuff like this happens that much. Thanks again for all your help. You guys are the best for giving the time to help us. Gary
AnswerHello Again Gary:
>>Wow, that is Really Unusual and Rare.
>>Thanks for the Feedback.
>>I will add this as a Check to Preform when a Questioner has this Type of Problem.
>>I am Glad you were able to Locate and Correct the Problem.
>>Thanks for the Ratings and Comments. They are Greatly Appreciated as that is the Only Pay we at All Experts Receive.
>>Till Next Time. May All Your Mechanical Problems be SMALL ONES and as Always, May the All Mighty Bless You and Yours. Be Safe and Happy.
Best Wishes and Good Luck
Respectfully
jbridger (John)
>>PS: I am Allowed to Answer 5 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
