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Engine won't stay running without choke


Rlw1406's Avatar
Member

Join Date: Jun 2008
Posts: 1
TX

06-20-08, 06:25 AM   #1  
Engine won't stay running without choke

Hello,
I Have a MTD 18 H.P. 42 in. cut mower that won't stay running unless I keep the choke fully closed. I have cleaned the carb and replaces the fuel line and filter but to no avail. Please let me know what to do next as I am getting heat from the wife to mow the back lawn.

Rick W


Last edited by Rlw1406; 06-20-08 at 06:26 AM. Reason: missed spelled
 
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Airman's Avatar
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Join Date: Feb 2008
Posts: 755
TN

06-20-08, 07:38 AM   #2  
You have a carburetor problem that requires thorough cleaning. Without engine model number, etc. I cannot give specific tips. Surging is an indication of a blocked idle or intermediate passage. This could be caused by stale gasoline or foreign object is blocking or restricting a passage. If your carburetor has a Welch plug I suggest you remove it and clean the passages behind it.

Here is a link to help you:
http://faqs.custhelp.com/cgi-bin/faq...i=&p_topview=1

If you have an Auto Zone parts store in your town, purchase a can “Valucraft Carb Cleaner” Part Number: AZ-4, 13 ounces in a yellow and black aerosol can with a red plastic cap. It for around $2.50 per can. I have been very successful in cleaning carburetors often without removing them from the engine. I have not had many carburetors I could not clean. Sometimes I use the entire can. At the price it sells for, so what.

WARNING - Do not get “Valucraft Carb Cleaner” in your eyes or on your skin. Use a full-face shield for eye and face protection. Wear protective gloves. The cleaner will damage rubber so remove rubber carburetor parts to prevent damage.

 
redfury's Avatar
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Join Date: Mar 2006
Posts: 33
MN

06-20-08, 06:00 PM   #3  
If that doesn't do it, I'd be willing to bet that you have the same problem I just got done fixing on my 1985 Huskee 18/42. Look for the thread called " the Surge". I beat my head up against the wall trying to figure out what I had already assumed. the main jet is clogged. If you pull it out, you'll find it has 4 holes on the sides and should have a hole going from the top to the bottom. The bottom hole ( in the taper ) is the one that will most likely be clogged. You can drill it out if you have a small enough drill bit and a safe way to clamp it without crushing it ( brass ).

Otherwise, buy a new main jet or a complete rebuild kit and be done with it. Dollars to donuts that's what is causing your problem.

 
Clamdigger's Avatar
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Join Date: Jul 2008
Posts: 1
KS

07-14-08, 04:06 PM   #4  
Posted By: Rlw1406 Hello,
I Have a MTD 18 H.P. 42 in. cut mower that won't stay running unless I keep the choke fully closed. I have cleaned the carb and replaces the fuel line and filter but to no avail. Please let me know what to do next as I am getting heat from the wife to mow the back lawn.

Rick W
I have an old Huskee 18/42, and I carry flathead screwdriver on so I can adjust the mixture screw on the fly when needed. Its on the front side of the engine on my Huskee 18/42, and can really help smooth it out depending on how hot of a day it is and or if its humid or not. Try adjusting it while its running and warmed up to find the sweet spot, should help it run a little smoother for you I hope. Good luck.

 
tybjepp's Avatar
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Join Date: Jul 2008
Posts: 3
MN

07-16-08, 04:58 AM   #5  
carb cleaning

They are not always easy to clean, you may need a jet cleaner , you say what its for cutting thorches cleaner. or a long small wire brush wire . just one wire be careful of size of the jet you are cleaning dont use anything to big, but find every jet you can and clean through it . they are small so look close in the throut and center behind the throtal plate or butter fly . and you can soak the carb in lacquer thinner, again no rubber parts in cleaners. And soak it over night if its really gunky, then air pressure to blow everything out good . good luck

 
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