QuestionQUESTION: Hi John,
Your responces have been very helpful in troubleshooting my surging problem - Thank you for your help!
As I mentioned earlier, I want to focus on the fuel filter visual that I am getting:
I have several similar tractors and 1 exact same tractor that I have compared the view thru the fuel filter with. With my other tractors, the fuel barely appears to be moving thru the transparent fuel filter. With this tractor that has the surging problem, I can actually see a powerful, steady stream of gas going through it. I took the fuel pump return line loose from the fuel tank and there is a garden-hose-like stream coming back into the tank. As you have proven to me in your earlier responces, my surging problem could be many issues. I am hoping that you or someone can save me a huge amount of time troubleshooting with this visual that I am seeing in the fuel filter and possibly the return fuel line back to the tank. Thanks Again!!!
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The text above is a follow-up to ...
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Hi John, thanks for your reply. I didn't soak the carb overnight but will try that if I end up taking it off again. The spring on the governor is inplace and seems to be strong, I have had to remove the spring and arm each time I remove the carb. Is there any adjustment to the governor? The way the spring arm attaches to the governor shaft it could be adjusted easily. The vacuum leak could be tough to find but I agree it is quite likely to be the problem. What do you think about the visual in the fuel filter I described? I am hoping that the fuel filter could help me narrow down my problem. Thanks for your assistance.
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Hello, I'm hoping you can lend me some advice. I have a 2000 John Deere 345 with 650 hours. It has a 20hp Kawasaki liquid cooled engine. I just bought this tractor and it had an engine surging problem when I bought it. I don't have history on the tractor. Here is what I have done so far to try and correct the surging: I drained the tank and put in fresh gas. I changed the fuel filter. I cleaned the air filter. I replaced an air breather line. I tightened (slightly) the intake bolts. I replaced the gaskets on both sides of the carb. I cleaned the carburetor 3 times. The final time I removed all the jets, float (everything that was removable). I ran a small wire through all openings. It still surges - at all throttle levels - this has not changed one bit after the above mentioned efforts. The surging will stop when I do 2 things - 1) apply partial choke 2) cover the air intake opening to the air filter (80% - 95% depending on throttle position). One thing that I noticed and hoping will help my diagnosis is that the see-thru fuel filter is acting very strange compared to 3 other similar JD lawn tractors I have. On the all 3 of the other tractors - while running the fuel in the fuel filter doesn't even appear to be moving through them. But, on the surging 345 tractor the fuel appears to be aerated (gurgled, spurting) and this is when I am covering the air intake and the tractor is running smoothly. Do you have any advise on where to turn next. Thanks in advance!
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Hello Jarrett:
1- Did you Soak the Carburetor Overnight in Cleaning Solution(I use Gunk Carburetor Cleaner) and then Blow Out the Passages with Compressed Air? Even though you used a Wire to Clean the Passages; there are Passages Inside the Casting that you cant get to to Clean. 2- This Engine uses a Vacuum Operated Fuel Pump. Any Leak in the Vacuum will cause this Also. Examples: Bad Diaphram in the Fuel Pump, Blown Head Gasket, Burnt Valve, Valve Stem Clearance Out of Adjustment or the Intake Manifold May have a Crack in it. Spray Some WD40 or Liquid Wrench Around ALL the Places a Vacuum Leak can Occur. If the Surging Stops; that is the Gasket or Part Causing the Problem. 3- Is the Spring on the Connector Rod from the Governor Control Arm to the Carburetor Throttle Thru Shaft? You can See this Spring at this Addy http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.H and Enter the Model Numbers 345. Then Select the Lawn and Garden Tractor File. Then Select Sectional View. Then Select Governor Linkage. This Spring is #26 on the Diagram. If this Spring is Missing you will NEVER get the Surging Out. Hope this Helps. I am here if you Require more Assistance. Thanks.
Good Luck
Respectfully
John
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Hello Jarrett:
Loosen the Governor Arm from the Shaft. Hold the Throttle Full Open and Turn the Shaft Clockwise. Start the Engine. If it Revs to Full Power and Doesnt Throttle Back, then Shut Of the Engine. In the Above Procedure, Reverse the Rotation of the Shaft(Counter Clockwise). This could Very well be the Cause of the Surge. The Governor will cause a Surge if it Slips on the Governor Shaft of if the Shaft Slipped when you Replaced the Shaft During the Carburetor Clean and Rebuild. Hope this Helps. I am Here if you Require more Assistance. Thanks.
Good Luck
Respectfully
John
ANSWER: Hello Jarrett:
I Think I Understand. Because the Engine is Surging the Fuel through the Filter will Also Surge/Pulse. I have Reviewed the Breakdown/IPL and have Also Spoken with the Shop Personnel. Your Problem is the Carburetor, Low Cylinder Compression on One Cylinder(blown head gasket usually), a Vacuum Leak or the Fuel Shutoff Solenoid. I Suggest; 1- Check the Compression on Both Cylinders. Is there a Big Difference in the Compression Readings? If Yes, then the Cylinder with the Low Compression May need a Valve Adjustment, a Burnt Valve or a Blown Head Gasket. If Compression is Good; 2- then You Spray WD40, Using the Extension Tube and Spray the Base of the Carburetor and the Gasket Points and the Intake Manifold Itself(it may have a hairline crack). If the Engine Smoothes Out, then the Place you are Spraying at the Time is the Cause. If No Change is Recognized; 3- then Remove the Fuel Shut Off Solenoid and Replace it with a Bolt of the Same Diameter and Threads. It should be 1/2 to 3/4 inches Long and a Flat Washer. Start the Engine. Did the Surging Stop? If No, 4- then Remove, Disassemble and Soak the Carburetor Overnight in Carburetor Cleaner(i use Gunk). Then Blow Out the Passages with Compressed Air. I'm Sorry the Fuel Surge Wouldn't Help with the Diagnostics. The Design of the Pump Allows this to Occur. Hope this Helps. I am here if you Require more Assistance. Thanks.
Good Luck
Respectfully
John
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QUESTION: John, Thank you for your continued responses. I am getting closer to a diagnosis because of your help.
Just to clarify, the fuel appears aerated in the transparent filter also when the motor is running smoothly, not just when surging. (Remember I can make the motor run smoothly by covering the air intake into the air filter).
I checked the compression on both cylinders. One is at 90psi and the other is at 75psi. They both seem to hold that pressure for a minute (thats all the longer I checked). As per your last responce, do you think I have a problem with one cyclinder?
Jarrett
Answer Hello Again Jarrett:
I am here to Help you Complete your Repairs. Check the Valves on the Low Cylinder(75psi). The Valves May Require Reseating, Re-adjusting or the Head Gasket May be Blown. The Cylinder Compression Should be within 5 psi of each Other. The More the Difference in Compression the More the Surge will be. I'd Look Really Close at the Head Gasket. Hope this Helps. I am here if you Require more Assistance. Thanks.
Good Luck
Respectfully
John
