4.5hp won't run


Old 12-12-00, 10:31 AM
Visiting Guest
Posts: n/a
I have an MTD snow blower with a 4.5hp Techumseh motor. Once it warms up if I open the choke it won't run. At half choke the motor will hunt. I was going to adjust the carburator, but it's sealed. I have plenty of gas (fresh) at the carb inlet and the gas cap is new. Any suggestions??
Sponsored Links
Old 12-12-00, 07:30 PM
Join Date: Nov 2000
Location: Austin, TX
Posts: 5,074

Trash in the carb or fuel lines.
Bad gas, low octane.
Or the motor has an air leak from a seal or gasket.
either way, the engine is running lean. Too lean to open the choke and allow even morew air. Your blowing the flame out.
Old 12-12-00, 08:02 PM
Sharp Advice's Avatar
Admin Emeritus
Join Date: Feb 1998
Location: The Shake and Bake State USA
Posts: 10,440


The low and mid speed ports in the carb are gummed up.
Most likely the engine sat for months with fuel in the carb, which has turned to gum, sludge and vanish.

The ports are very tiny holes in the venturi of the carb. The sludge and gum has closed them off <plugged'em up> and fuel will not flow thru them.

The only permantent solution to correct this problem is to soak the carb in carb cleaner and install a rebuild kit.

If you have never done this type of job, need the blower back in service quickly, you may want to have it done at a local small engine repair shop.

If not, attempt to doityourself. Just remember how the carb came off the engine and came apart and put it back as found. <Hint: Take notes> Besure to allow plenty of room, on a cleared off well lighted work bench.
Old 12-20-00, 02:45 PM
Visiting Guest
Posts: n/a
What about using some carb cleaner in the gas like in a car?
Old 12-20-00, 06:32 PM
Sharp Advice's Avatar
Admin Emeritus
Join Date: Feb 1998
Location: The Shake and Bake State USA
Posts: 10,440
Thumbs down It Doesn't Work


Adding carb cleaner to the fuel fails to do the job more times then it works. If you want to give it a try, then attempt it but don't be surprised if it fails.

As I outlined in my prior post, you'll either have to remove and disassemble the carb or have it done at the local small engine <lawn mower> repair shop.

If you care to attempt it yourself, take the carb apart and use the aerosoled can carb spray cleaner. The plastic extention tube that comes with the can of cleaner will force out the gum/sludge from the ports, if injected into the larger holes in the fuel bowl body.

If this method is done correctly, it will do the same as soaking a carb in a can of carb cleaner. Done incorrectly, it will not work well. It's a chance you may not want to take.

Be sure to wear eye protection doing the above. That spray cleaned will come out of several places you'd least expect and get into the eyes!
Old 12-26-00, 04:49 PM
Visiting Guest
Posts: n/a
Thanks guys
A very inexpensive rebuild kit did the job. Found a lot of corrosion around the float bowl sealing surface.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes