Small Engines (Lawn Mowers, etc.): Tecumseh running only on quasi full choke, mtd snowblower, snowflite

Question
Hi Eric,

It worked!!! I guess the carb was pretty dirty. Thank you very much by the way!

Now I think that the blower's transmission wants to leave me. For a reason I don't know I was opening the driveway with the snowblower and the thing didn't want to move forward or back. If I was lifting the wheels off the ground I could see they were spinning. It seemed that they had no power enough to move the blower. So I pushed it around! :-) About two hours after, I started it back and the wheels were spinning with enough power this time... I seemed that the problem was gone just like that...

Could this be a sign of a worn transmission?

neilsanner

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Followup To
Question -
Hi Eric,

Yesterday I dis-asembled the carb. I removed all the o-rings and gaskets that I could find. In the tech guide they also recommend to remove welch plugs when cleaning the carburator. It's just that it seems that I can't find it. All I see is a soft baffle plug, but they don't specifically ask to remove this one. On the diagram of that carb they specify a welch plug, but it's not very clear where it is exactly. It seems to be behind the throttle shutter...?

This is a float style, Series 3 carburetor.

I've already drown the carb overnight in a Gunk engine flush liquid but it seems that this stuff isn't strong enough. It's all I've found at the walmart last night. I'll go check somewhere else today for a cleaner specific to carbs.

Regards,
NeilSanner

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Followup To
Question -
Hi Eric,

Thank you very much for your answer. As soon as I have a chance I'll try your suggestions. I'll let you know how it goes.

Have a nice day!
NeilSanner

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Followup To
Question -
Hi Eric,

I have a SnowFlite (by MTD) Snowblower. The engine in it is a 10.5HP Tecumseh Snow King LH358SA (same as HMSK110 I think). To get it started the primer needs to be pushed several times (10+; about tree push per trial). Once started and warmed up, it only runs at full choke or at a notch before full choke. If I try to turn the choke button towards the no choke position, the engine will stall. So I let it quasi full choke all the time I'm working with. It does the job, but it seems to lack some power. After 15-20 minutes it seems to make more and more backfire sounds.

I did an oil change recently but the engine was having this behavior before it.

Is there an an air or gas filter on that engine that can be changed? I've looked in the Operator manual and in the technician handbook (692509) but it doesn't specify the exact location of those filters (if they ever exist).

Do you have an idea of what could be the problem with this engine?

Best regards,
Neil
Answer -
Snowblowers rarely have air filters or fuel filter.  If you have a fuel filter it may be a small screen molded in the bottom of the fuel tank.

We see this problem quite often.  The repair usually consits of removing, dis-asembling and cleaning the carburetor with compressed air and carb cleaner.  On really tough/dirty carbs we will remove all carb parts and soak the carb in some strong cleaner and repeat the process as necessary until the carb runs properly.  We have had to soak and clean(blow out) some carbs several times before they ran correctly.

I would also recommend checking the carb to manifold gaskets and make sure the headbolts are torqued to 200 inch pounds.

The carb sounds like it is running lean, not providing enough fuel to the engine.  Most likely a small passage/orfice or two contain some debris preventing the carb from working.

Does this help?
Eric
Answer -
No problem.  There are some carb diagrams on the net if you need a picture.

Let  me know how it goes.

Eric
Answer -
The welch plug is located on the bottom of the carb.  It is the only disc/round part on the bottom.

I would not remove it unless the second or third carb cleaning does not fix the problem.  

Find some stronger cleaner, reassemble and see how if runs.
Let me know if the first cleaning helps.
Eric

Answer
Many times the slipping is caused by the drive disc or belt.  You can tilt the blower forward to see which system you have.

Also, on some MTD models there is a bushing in the side for the axle that tends to come out.  You can remove the wheels to check but normally you can look around the tire to inspect the bushing.

Let me know if you have a belt or drive disc.
Eric