LCT 179cc Engine - Stalls after running for a long time - fuel starvation.

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Sep 10, 2005
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Erie, PA
I am utterly tearing my hair out of my scalp. This is a craftsman snowblower with this engine and it is very low hours and use, most likely because of this issue.

It will run for quite a while 15-20 minutes then pops, spits like it is fouling out a plug or loosing spark It is NOT!!!!!!! The moment it dies I can test and it has a nice bright purple spark.

Its almost like it cant draw in fuel properly or heat locking the fuel system. If you blow into the gas tank it will start back up run for a short while then die back out.

I cleaned the tank, removed the filter screen and cleaned it, and also cleaned the carb and emultion tube. I also enlarged the main jet to stop the hunting, and it actually helped prolong how long it runs. Leaving the gas cap off makes no difference, and the cap vents just fine.

What is causing it to not meter fuel correctly only when hot?
 
Will it stay running if you put the choke on when it starts to sputter?

Will it stay running with the gas cap off? (plugged gas cap vent)

Other than those, all I can think of is something is changing due to expansion/contraction when it gets hot. The OEM fuel line is garbage on these. All the soft bits are.

If for sure it's not a spark plug or coil issue, maybe a fuel circuit in the carb is choking off when the carb gets hot?

I've got the 208cc version of the LCT engine on my ~2015 model year Ariens SnoTek. I've had to replace the fuel shut off, all the fuel and primer bulb lines and the gas cap. One auger shaft bearing and the friction disk also.
 
Have you try another spark plug? They can seem good, but not work anyway. Especially if it is the original. I have had new plugs be bad.
 
Will it stay running if you put the choke on when it starts to sputter?

Will it stay running with the gas cap off? (plugged gas cap vent)

Other than those, all I can think of is something is changing due to expansion/contraction when it gets hot. The OEM fuel line is garbage on these. All the soft bits are.

If for sure it's not a spark plug or coil issue, maybe a fuel circuit in the carb is choking off when the carb gets hot?

I've got the 208cc version of the LCT engine on my ~2015 model year Ariens SnoTek. I've had to replace the fuel shut off, all the fuel and primer bulb lines and the gas cap. One auger shaft bearing and the friction disk also.

-The choke will help but not solve.

-Yes as stated earlier I left the gas cap off and it does vent fine anyways. No change at all.

-Fuel line was great, flexible, and no cracks, but I guess I could change it.

-I tried a used plug out of an engine not experianceing this issue and the plug I transfered has no issue in the other engine. The fuel circuit choking off when warm makes sense but why, I have never experianced this on a non diaphragm carb before.

-Id be glad to replace the carb if I could pinpoint that as being the problem. Again never experianced it before and honda and predator use a very similar carb.
 
-The choke will help but not solve.

-Yes as stated earlier I left the gas cap off and it does vent fine anyways. No change at all.

-Fuel line was great, flexible, and no cracks, but I guess I could change it.

-I tried a used plug out of an engine not experianceing this issue and the plug I transfered has no issue in the other engine. The fuel circuit choking off when warm makes sense but why, I have never experianced this on a non diaphragm carb before.

-Id be glad to replace the carb if I could pinpoint that as being the problem. Again never experianced it before and honda and predator use a very similar carb.
The Chinese clones can have questionable carbs (especially jets). I'd put an NGK spark plug in and replace the carb and you'll prob solve all issues for under $30
 
New NGK spark plug. Try that. Chinese plugs do weird things.

If it still occurs, gap the plug at .020. If it gets better, the coil is shot.
 
New NGK plug = no change. Suspect plug transfered to another engine and it ran fine.
It is not loosing spark at all.
 
The Chinese clones can have questionable carbs (especially jets). I'd put an NGK spark plug in and replace the carb and you'll prob solve all issues for under $30
I had one with a similar issue. Cleaned the carb probably 3x in the ultrasonic cleaner, kept dying out when hot. I ended up just swapping the carb in an effort to troubleshoot, and no more issues. Good ole' China carburetors. :rolleyes:
 
If you blow into the gas tank it will start back up run for a short while then die back out.
This doesn't make sense to me since taking the cap off made no diference so I'm thinking it's a coincidence. I wonder if keeping the gas tank full would help.
 
Pressurized the tank (blowing in it) makes it start sooner every time?

When it dies out, if there is a bowl drain, immediately remove it and see what fuel flow is like
 
Pressurized the tank (blowing in it) makes it start sooner every time?

When it dies out, if there is a bowl drain, immediately remove it and see what fuel flow is like
This.

My bet is there is an issue with the needle/seat. Some of these Chinese carbs have a ton of issues with that because the seats aren't machined correctly.
 
Aren't you just replacing a cheap chinese carb with another cheap chinese carb ?
Yup, and sometimes it takes a few tries. I've gone through 4 replacement carbs before on a snowblower for a customer before I got one that the needle valve worked correctly. Sometimes on Kohlers/Briggs I'll try to sway people towards OEM if it isn't too much more expensive just because of the labor/wait time involved with replacing 4 carbs in a row before finding a good one. Sometimes it isn't a good option though when an Amazon carb is $15 and the OEM is something ridiculous like $200.
 
Yup, and sometimes it takes a few tries. I've gone through 4 replacement carbs before on a snowblower for a customer before I got one that the needle valve worked correctly. Sometimes on Kohlers/Briggs I'll try to sway people towards OEM if it isn't too much more expensive just because of the labor/wait time involved with replacing 4 carbs in a row before finding a good one. Sometimes it isn't a good option though when an Amazon carb is $15 and the OEM is something ridiculous like $200.
Had to replace the carb on my '95 MTD Tecumseh blower. Found a OEM carb for $100 3 yrs ago, yeah pricey but no issues since then and the blower is working fine at my other place in the lake effect snow zone. It needs to start and run right there as it gets serious usage.
Price of a OEM carb is still less than a new blower or motor not to mention lessening the aggravation factor.
 
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