QuestionQUESTION: MTD snowblower 8/26 2-stage. Two things> Engine will only run when in full choke, turn choke off, engine quits. And press right lever down on handle to engage wheels, but will not go forward, or backwards when in gear.
ANSWER: Hello Larry:
1- >>From your Description of the Engine Operation it Sounds like the Carburetor Jet is Restricted and the Carburetor Requires Soaking and Cleaning.
>>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 Suggest you Make Sure the Gas is Free Flowing to the Carburetor Inlet Port (if the Model does Not have a Fuel Pump). If the Gas is Free Flowing to the Inlet Port, then
>>**Remove, Disassemble and Soak the Carburetor Overnight in Carburetor Cleaner (I Use Gunk).
>>The Primer Bulb is Held in Place with a Locking Collar at the Base of the Primer Bulb. Use a Small Flat Screw Driver and Carefully Pry the Lock Ring Up in Small Amounts All Around the Lock Ring until the Lock Ring and Primer Bulb can be Removed from the Carburetor Body. Usually a New Primer Bulb is Required when you have to Soak the Carburetor. The Rubber is Usually Rotted to Much for the Primer to be Reused.
>>Your Primer Bulb May Differ Slightly, but Removal is Usually Almost the Same Except for the Primer Bulbs that are Bolted to the Carburetor. These are Simply Unbolted and Changed with the new Primer Bulb.
>>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 and Needle Valve Seat if Applicable. This is a Flat O-Ring Located in the Inlet Port the Float Needle Rests in. Use a Strong Wire with a Slight Bend to Remove the Old Seat. Sometimes a Small Pocket Screw Driver can be Use Also.
>>The New Seat will have a Slightly Beveled Side and a Flat Side. The Flat Side goes Towards the Carburetor Body when Inserted into the Inlet Port. Spray the Seat with Spray Lubricant to make Installation Easier. The End of a Drill Bit that is Slightly Small than the Seat can be Use as an Insertion Tool.
>>Wear Gloves or Use a Rag when Handling the Sharpened End of the Drill Bit. 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. Even the O-Ring Around the Bowl can be Reused if it is Not Broken. The Only Parts you May Need to Replace is the Float Needle Valve (and Seat if Applicable).
>>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 .
2- >>From your Description of the Unit Not Operating it Sounds like the Belt May have Broken or has Jumped Off the Pulley.
>>The Numbers you Sent me are the Series Model Numbers. I Require the Units Model Numbers.
>>Generally the identification tag is on a part of the unit that, even after years of use, rarely needs replacement. For most of MTD power equipment, these tags are approximately 2" by 3" in size. They also have the MTD Products name, address and customer service phone number listed across the bottom. For hand held product, the tag is normally white and approximately 1" by 1/2" in size. Hand held i.d. tags are normally on an aluminum portion of the engine, somewhat set into the unit to protect the label from wear. (A bar code will also be on this tag.) Riding mower tags are located on the underside of the seat. For walk behind mowers this tag is found either on the deck or on the rear door of rear discharge units. Tiller model and serial tags are generally on the tine housing. **The model and serial tags for two-stage snow throwers are located on the bottom of the main gear housing which is often called the belly pan, while single stage snow thrower tags are next to the key and primer. For other products like log splitters, chipper shredders and edgers, tags can be found on the frame or main housing.**
>>Send me the Model Numbers Off the Unit, Please. With these I can Locate the Proper Manual and Better Assist you.
>>You can View a Breakdown/IPL of this Unit 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 (MTD) and Enter the Model Numbers (). Then Double Click on the Model in the Results Area. Now you can Select the Section of the Unit you Wish to View.
>>Please, Do Not Hesitate, If you Hit a Snag, if I Missed Something 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. Comments and Ratings are Greatly Appreciated. Thanks.
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: Hi John,
Thank you greatly for a very informative answer.
Now, I did get the wheel problem fixed, as the key was out of the keyway under the sprocket gear, and that prevented the wheels from being engaged. My question is now with the carb. It is a Tecumseh engine HMSK 80 1555450 (H) I believe the idle air mixture screw is on top of the carb bowel, and the screw on top of the carb body that requires a "star" screw driver to turn. Is this an idler air screw also ? And do I turn both in snug, then turn both out one and one/half turns. And do I do the same with the screw on the bottom of the carb bowel. The "star screw" is the one that is really confusing me?
The MTD snow blower is Model # 317E640F088 TMO-3525401 Serial # 11206B50179.
Again, thanks so much for your help.
Larry
ANSWER: Hello Again Larry:
>>Sorry, I Clicked the Send a Thank you Note by Accident.
>>Thanks for the Model Numbers.
>>>>You can View a Breakdown/IPL of this Unit 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 (MTD) and Enter the Model Numbers (317E640F088). Then Double Click on the Model in the Results Area. Now you can Select the Section of the Unit you Wish to View.
>>If this is a Tillotson Carburetor, you can View a Breakdown of the Carburetor at this Site Addy http://www.tillotson.ie/ and Download the Flash Player. Then Enter the Site. Now Select Tech Info. Now Select Service Manuals from the Drop Down List Under the Tech Info Tab. Your Carburetor should be in the HU or the HS Series Manual.
>>It has been a While since they Manufactured a Carburetor with the Idle Air Mixture Screw Straight Down on Top of the Carburetor as you Described. However, it is Possible your Carburetor Does have this Design.
>>For this Unit I will Require the Carburetor OEM and Model Numbers. The Model Numbers will Usually Start with an HU or HS.
>>The Site Addy I Listed Above is for Tillotson Carburetors because Tecumseh Engines Usually have these Carburetors on them.
>>The Star Screw should Actually be a Torx Screw.
>>Once I Receive the Carburetor Numbers I can Assist you Better.
>>Thanks.
Respectfully
John
>>Please, Do Not Hesitate, If you Hit a Snag, if I Missed Something 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. Comments and Ratings are Greatly Appreciated. Thanks.
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: Hi John,
I stated poorly the screw position. The Idle Air Mixture Screw is not straight down on top of the carb. It is near the top straight in from the side, and, indeed, it is a Torx screw.
On top of the carb is the number 143216 H. I tried the Tillotson site; but was unable to open the service manual site.
I'm trying to get the carb set right. Do I turn out the two screws on the side one and one/half turns, then try to start engine, or do I also turn the bottom screw(under carb bowl) out the same and then start engine ? How do all three screws function together ?
Thank you again for very informative information.
Larry
AnswerHi Larry:
>>No Worries. It Happens to me All the Time and I even Accidentally Do it to Questioners Also.
>>The Following is an Instruction File I made for Correcting this Problem. Any Input is Appreciated.
>>****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 Horizontally 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 Nearest to 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 Rapidly Throttling from Idle to Full Throttle. Reset the Engine Idle if Required.**** If This Carburetor has a Single Air Adjustment. 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.**
>>You can Tell the Engine Idle Screw because it Doesn't Enter the Carburetor Housing like the Idle Air Screw Does.
>>Please, Do Not Hesitate, If you Hit a Snag, if I Missed Something or this Does Not Correct the Problem, I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please and as Always, May the All Mighty Bless You and Yours. Be Safe and Happy. 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
