# Snowblower Dies after 8 to 10 minutes, 2004 MTD Yard Machine, 8 HP, Tecumseh Engine



## Audubon (Jan 5, 2018)

I am a rookie, trying to get my hands dirty on a hammydown snow blower, i used it 2 seasons ago (2015-16 winter), then in 2016-17 winter it would not start. This year (2017-18) i was committed to try and get it back up and running. 

Snowblower: 2004 MTD Yard Machine, 8 HP, Tecumseh Engine

1. i cleaned the carb bowl, unclogged the mixture screw

result: snowblower started and would run, but leaked like a siv when i shut if off. After messing around in the carb i messed up the seat and needle.

2. replaced float, needle ... did not replace seat.

result: snowblower would start, would not leak (on or off), would run for about 5 to 10 minutes then die. It felt like not enough fuel was getting to the carb or engine. while repairing the carb the i had pulled on the fuel line which as a result felt like it was pulled tight and remained that way. 

3. I replaced the fuel line (as well as put in a shut off from the fuel tank).

result: snowblower would start... then die after approx 10 minutes, sometimes would run longer felt like i got 20 minutes out of it but that could simply be revisionist history. Muffler glows red at times, evens sparks. I read somewhere it could be "running lean". 

Any ideas on what to try next based on some of these symptoms, im all ears.


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## jtclays (Sep 24, 2010)

Audubon;1409298
result: snowblower would start... then die after approx 10 minutes said:


> Sounds like


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## orangputeh (Nov 24, 2016)

maybe gas cap is not venting?

longshot.


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## Sblg43 (Jan 18, 2014)

My first thought - did you let it warm up and then adjust the "adjustment screw" accordingly? It may indeed be running lean.

My second thought - could the ignition coil be going bad? As the engine runs and the coil "warms" up, it may stop sending spark. If you can get it running for several minutes, and it dies again - check for spark immediately while it's still "warm or hot".

Another alternative - get on Ebay and buy an aftermarket carburetor for less than $20. I have replaced two or three with good results (all on 8HP Tecumsehs).


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## drmerdp (Feb 9, 2014)

Glowing muffler is certainly a leancondition. You may need to try another thorough* cleaning or simply by a new carb off eBay.

If you go that route buy an adjustable carb, that way you can really fine tune the machine for power, not emissions.

If you try cleaning your old one again, I’d replace the seat as well and set the float high per spec. If you google tecumseh float height, you’ll find what size drill bit to use as a spacer.

I’ve also seen so many tecumsehs stall or run terrible due to insufficient valve lash. Usually the exhaust, the valve cannot close properly, dumps compression and dies.

Usually you’ll catch flames from the exhaust accompanied by loud pops.


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## Sblg43 (Jan 18, 2014)

drmerdp said:


> I’ve also seen so many tecumsehs stall or run terrible due to insufficient valve lash. Usually the exhaust, the valve cannot close properly, dumps compression and dies.
> 
> Usually you’ll catch flames from the exhaust accompanied by loud pops.


Ditto.

I recently fixed a machine that was running rough and had a glowing red muffler. I removed the head and valves, cleaned everything, lapped the valves, cleaned and rebuilt the carb (new needle and seat) and now it runs great.

Although the valves didn't look bad, and I can't be sure that was causing the trouble, after all that work, I was pleased with the results.:smile2:


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## JLawrence08648 (Jan 15, 2017)

I agree with jtclays and orangeputeh, change the gas cap or remove it and see if it stops, use a rag if necessary, get a rubber plug from the hardware store and drill a hole in it.


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## vinnycom (Nov 6, 2017)

float bowl set too low
or fuel cap not venting , test- remove cap just b4 it wants to die and see if it runs longer


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## classiccat (Mar 1, 2014)

drmerdp said:


> I’d replace the seat as well and set the float high per spec. If you google tecumseh float height, you’ll find what size drill bit to use as a spacer..


11/64" (4.36mm)


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## CarlB (Jan 2, 2011)

i vote for no lash on the exhaust valve holding it open and causing the muffler to glow red and engine to loose power. I seen the many times before. File/grind the valve stem to get proper lash.


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## Snowbelt_subie (Dec 20, 2016)

I would go about it like this.

1. when it dies check for spark at that time to rule out a bad coil.

2. get a cheap adjustable carb of ebay it will serve you well in the future in being able to tune and rule out any carb problems with the existing. they are 10-15$

3. last i would do the exhaust valve lash its the most work and time i wouldnt touch it unless i tried 1 and 2.


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## jtclays (Sep 24, 2010)

Ano


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