10Hp Snow Blower troubles

giuseppe105

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I have a 10HP HM100 15xxxxxxxxxx snow blower, that has been giving me trouble for a while now. (if you want all the extra numbers I will need to remove the electric start button)

What I did to prepare for the winter.
Before I put gas in it I took the main jet out, cleaned all the holes with a fine wire. Even the super tiny one on the main jet. I'm talking about the one that you can barley see.

I have an adjustable main jet so I took that apart and cleaned it as well. I pulled the bowl off and clean it out, there was barely any varnish everything was really clean.

I made sure my pin and seat were working good, It felt like it was stuck shut and made a click when the float pulled it down. I assume that is good. It appeared to be working correctly.

With reassembly I made sure that the lower part of the bowl would allow the float to drop down low. and made sure the adjustable jet was 3 ~3.5 turns out

I cleaned the spark plug with a wire brush and some soft sanding, it was very black and sooty.

I put some fresh gas in it, primed it till I saw gas come out the air intake. And started it up.

Additional Info
plastic tank, with new gas lines, new gas filter.

Problems
1. The throttle gets pulled in a bit despite me setting it to max. When I use the machine I need to hold the throttle out all the way to throw snow further, the machine wont stall while under load in half throttle.
2. The machine will just shut off after its been running great for a minute or two. (I can use the auger and 3,2,1 + reverse without it stalling with no choke)
3. The tank mysteriously empties, I thought I left gas in the tank when I put it away last winter. But I found it bone dry. I can't see any leak.

I read around on the internet that the gas cap might be broken, so I removed the gas cap and ran it, it still shut off.

If I give it 3/4 choke it seems to stay running. Could this have anything to do with the weather/carb tune? Its 8C outside today(I have been turning in the main jet slowly and checking the spark plug to see if I have a good mix).

After it turns off I can immediately start it again with one pull, no prime, full choke, once it starts I can quickly remove the choke and it will run.

Any help would greatly be appreciated, I don't wanna be shoveling this winter.
 
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Rivets

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I figured I would see this problem soon, as folks try to get their blowers ready. Common problem and I've done about 3-4 dozen repairs like this already. You need to clean and rebuilt your carb. Yes, I see that you say you have cleaned it, but just cleaning won't help. This is the procedure I use almost every day in the shop and if followed, I'll bet you will solve your problem. You will need to buy Tecumseh carb kit #631021B. Read the procedure throu a couple of times before starting and don't skip any steps. After following the procedure your initial adjustment for the high speed needle will be 1 1/2 turns out from lightly seated and the idle needle will be 1 1/4 turns out from lightly seated. This will get you started and you can make your final adjustments with the engine running.

Needle and seat replacement

Remove the carb, and then remove the float bowl. Check the float bowl jet (which is the bowl screw) and make sure the jets both horizontal and vertical are clean and open. Tip the carb upside down and remove the float pin and float with needle attached. Look in the float needle passage and you should see the red float seat at the bottom of the passage. This is where a #5 crotchet hook would come in handy as you need to remove this seat. If you have no hook, but compressed air, you can blow through the fuel inlet and try to pop the seat out. Put your thumb over the passage to prevent the seat from flying who knows where. No air or hook try bending a stiff paper clip to dig the seat out.

I would either give the carb a good 24 hour soaking or have it ultrasonically cleaned at this time.

With the seat out clean the passage way with carb cleaner. Now you must find a drill bit slightly smaller than the passage way, to be used to press in the new seat. Apply a very, very small amount of a very light lube to the new seat. 3-1 oil or lighter, to help seat it better. Carefully insert the new seat in the passage way with the rings on the seat down toward the carb body. Slowly and carefully force the seat down with the back end of the drill bit. Once it is seated, check to see that it did not flip and the rings are up. *Next check to make sure that the float does not have any liquid in it. *If it does, replace. *If everything looks correct, attach the new needle to the float and install with the float pin centered. It everything is correct, the float should seat level to the carb body, when looking at it upside down. If everything looks good reattach the float bowl, making sure that both the bowl gasket and the nut gasket seal properly. Reinstall on the engine and test unit. Remember to have patience and take your time. Good luck, but I don't think you'll need it.

PS: *On the side of some Tecumseh carbs you will find a plastic cover. *Under this cover will be an idle jet. *Remove it and check to see that the jet is open both horizontally and vertically. *You should be able to push the old float needle wire through the vertical opening.
 

giuseppe105

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Jun 4, 2012
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Thank you for your reply Rivets.

I have not purchased the kit yet. I got the snowblower from a repair shop, i'm not sure if they already went through the carb, before I got it. Ill know for sure when I inspect the seat to do the work.

I was curious what in my original post leads you to believe that the seat is the problem? If it was not sealing would I not have gas pouring out the intake?

Also I read somewhere on the internet that when messing with the carburetor I need to leave pressure on the governor otherwise something will fall into the engine. Do I need to worry about this on my engine?

On a side note. I don't want to derail my thread, but forgive me.
I am also helping a family member with their snowblower, it also has a bad seat. Gas was pouring out the intake and the spark plug is very sooty and black. While working with the engine its a 5 3/4 HP, when I turn it over it is making a sound almost as if its knocking. The oil is jet black and Iv never heard it running. I am concerned if that governor piece fell into the engine and that's whats clunking sound is or if its rod knock. I am leaning toward rod knock because it only does it at the top or bottom of the stroke not while its going up or down.

Thank you again for your time and wisdom.

Edit: I may sound like I know what I'm doing but I have no experience.
 

Rivets

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As someone who has been working on small engines for over forty years I have seen your problem more times than I would like. Only good thing is that it keeps paying the bills. Today float needles or seats (depending on the make and style of carb) are made of a product called viton. This material will swell and/or distort when left in bad fuel over a long period of time. When this happens one of two things will occur. Either the n馥 de will close too soon causing a lean starting and running condition or it will not close at all causing a rich condition. Even though there are many on this forum who disagree with me, in my opinion and findings ethanol in today's fuel will also cause the same problem. I rebuild carbs just about every day I am at work and I always replace the float needle and seat. In your case I would be rebuilding both carbs using the procedure I posted.

PS: Don't worry about the governor, as on 99.99% of today's engines the governor shaft can not move far enough for something to fall into the engine.
 
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