QuestionQUESTION: I replaced my carburetor with a used/allegedly rebuilt carb on an 8 hp (model # 195437) generator. After it warms up, the engine runs OK and then it dies all the way down, revs up runs OK for a few seconds before dying down again. If I spray carb cleaner down the throat of the carb it won't die all the way down. I checked for intake manifold leaks by spraying carb cleaner at the intake gaskets, it did not seem to make a difference. I've tried adjusting the needle valve and idle mixture screw, the result is the same. It would seem obvious that the problem is in the carburetor. Is there anything specific I should look for?
Thanks.
ANSWER: Hello Elizabeth:
Is the Gas Free Flowing to the Carburetor Inlet Port? If Yes, then Remove, Disassemble and Soak the Carburetor Overnight in Carburetor Cleaner (I Use Gunk). 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, Float Pin, Float and Needle Valve and Any Adjustment Screws that Go Into the Carburetor Body. The Welch Plugs Do Not have to be Removed. 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. Install New Parts if Required. There is Trash Restricting the Main Jet or the Inlet Port and Causing the Engine to "Hunt" for the Correct RPMs. You can View a Breakdown/IPL of this Engine at this Site Addy, http://www.smallenginepartswarehouse.com/parts.asp and Select the Shop Online Parts Look Up. Then Select the Model Tab. Then Select the OEM and Enter the Model and Type Numbers. Then Double Click on the Model in the Results Area. Now you can Select the Section of the Engine you Wish to View. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. 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 9pm EST (US). My New Day Starts then. Thanks.
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: Hello John, thanks for the advice. Gas was freely flowing to the inlet port, so I went looking for some carb cleaner. The both local parts stores were out and they were having a hard time finding any to sell me, apparently they were having trouble with the stuff eating through the containers and and leaking. I'm not sure if that is something I want to have around, although it sounds quite effective.
Back to the carburetor. I took the carb apart as much as you advised and blew it out with compressed air and a can of carb cleaner. I focused on the long jet (I think that is the main jet?). I have three, since I have the old carb, this carb and a rebuild kit. I tried using the jet from the old carb, since it had the most holes (smaller) with them spaced at different heights on the tube. It looked like that would be most effective at vaporizing the fuel, although the threads were significantly worn. When I started the generator, it ran fine for a few minutes and then started misfiring and I could see flames popping out the muffler. Out of curiousity, I replaced that long jet with the one from the rebuild kit, and the generator now runs more smoothly. I was surprised, since I would have associated the flames with timing, not fuel. Perhaps you can shed some light on that. Now the generator runs acceptably, but the idle still fluctuates somewhat (regardless of electrical load). Not enough for someone not listening to it to notice, and I am also used to cars idling. Does that sound right? I intend to use this generator for emergencies, and we do lose power often in the winter, so if it's not right I definately want to get it the best shape I possibly can.
I also have another question: in adjusting the carb, I was following the owner's manual and it says to hold the throttle against the throttle stop and adjust the idle screw to obtain 1750 rpm. Does that mean the lowest idle is 1750? When I put my tachometer on the plug wire it reads ~700 although it is definately running what sounds like closer to 1800. Again, I am used to cars and tested my tachometer out on a car and it was working fine. Why won't it work on the generator/ is that common?
Thanks for all your help.
ANSWER: Hello Again Elizabeth:
The Carburetor Cleaner is Effective, but I have Never had the Problem of it Leaking from the Gallon Container it was Packaged it in. However, I Use the Cleaner Often and a Gallon Only Lasts About a Month if I am Lucky. On a Single Cylinder Engine if the Gas is Too Lean it can and Most Times Does, Misfire like the Coil or Point Set is Breaking Down. I Just Looked at the Breakdown for this Engine and was Wondering if you had the Idle Air and Main Air Mixture Screws Set Properly? Here is the Instructions for Setting the Mixture Screws. ****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 the Farthest from 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.**** Depending on the Model, An Automotive Tach is Designed to Operate with 3, 4, 6 or 8 Cylinders and Does Not Operate Properly on a Single or Twin Cylinder Engine. If the Tach Read 700 RPMs, then Usually the Engine is Actually Running Closer to 1400 RPMs or 2100 RPMs. Most Generators are Set to Idle and Operate at One Speed (1800 RPMs - 2000 RPMs) Anymore. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.
Good Luck
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: Hi John,
Thanks for your answer. I’ve adjusted the carburetor based on the instructions in the owner’s manual, which are very similar to yours. It appears to be running well—I ‘test drove’ it for over 15 minutes and it ran fine until it ran out of gas. So for now, I will call that good.
The next step is to get the generator running on propane (it is a tri-fuel model Winco TF4500 E/M generator). I had the gas valve off (and am also out of gas), re-adjusted the spark gap to .025” (though I had also tried with it at .030”), opened the gas valve on the propane tank—it goes through a regulator that is mounted on the generator frame, made sure the ignition switch was ‘ON’, and turned over the engine. But it will not start. I have no experience running engines on propane. Is there anything you could recommend?
AnswerHello Elizabeth:
When Switching from Gas to Propane on My Generator, I Usually Vent the Air from the Propane Line at the Carburetor Inlet. This Makes the Starting Easier and Quicker. Send me the Model Numbers Off the Generator, Please. With these I can Locate the Proper Manual and Better Assist you. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.
Good Luck
Respectfully
John
