Craftsman Snowblower w/ Tecumseh Engine Problem

[FortyCaliber]

Hi all. New here. Thanks for starting this forum after Perr closed up.

I can't get my snowblower to idle. It's a Craftsman 31A-3BDE799. It's powered by a Tecumseh 5.5 HP engine, Model # LH195SP, Spec 67517D. I live in Toledo, Ohio.

Last year it died on me after the first snow. It got really cold outside, and started snowing almost non-stop, and with all of the other things I have to do, I didn't have time to mess with it last year. So, I shoveled a LOT of snow the rest of the Winter. I swore I'd get it running this year, hopefully before it snows, and that's what I'm trying to do now.

It "had" the (OEM) non-adjustable, EPA carburetor on it (640084B). I cleaned and rebuilt (with kit) the carburetor. I could not get it to start. It puttered once or twice, but would not start. I had the carb off probably 10 times. I ran wires through all the holes and blew out with air. I could not get it to start. I gave up on it.

I bought a new carburetor. The carburetor I bought is a 632107A. This is supposed to be the equivalent carburetor to the 640084B, only with the adjustable main and mixture screw. I installed it, cleaned out the tank, filled with new fresh gas, and I got it to run. I had to mess with the adjustments some, but it started without a lot of hassle. To me that seems to indicate that there was indeed something wrong with the old OEM carburetor.

The thing is now I cannot get it to idle. I ran it for at least 20 minutes at higher RPMs. There was a little popping. As soon as I move the throttle lever down, the RPMs drop and it eventually dies, even if I try and keep it running before it dies by applying a little choke. Because it ran for at least 20 minutes, that seems to indicate, at least to me, that the gas cap vent is good and the ignition is good, which, at least, eliminates those potential causes. Is that correct?

One of my concerns is I messed with the governor when I was trying to get it running with the old carburetor. I don't know why. My bad. I've tried to adjust it, but nothing I do seems to help any. When I had the linkage and spring unhooked, I rotated the governor shaft. It barely moves. "Maybe" 5 degrees of total movement. I was on YouTube watching a video where a guy with another Tecumseh was showing how to adjust the governor, and when he rotated his governor shaft, it moved a LOT more than mine, like 20 or 25 degrees, I estimate. I have no idea if this has anything to do with my non-idle issue. Also, I sprayed some Ether, carefully, at the carb/intake flange while it was running and didn't notice any RPM change or otherwise, so it seems like I have no air leaks. I'm using E10 gas. E0 is not available in my area.

Could the idle circuit of the new carburetor be not working properly? Other causes? I haven't checked the valves or anything else. I've never done that before. Compression seems good to me (not checked with gauge), but it did run fair at full throttle. I don't know what actual (fast) RPMs are since I don't have a tach. I can get one if need be, but someone will have to tell me how to use one on a small engine. Oh yeah, the spring and throttle linkage are in the exact place from where they were removed before I replaced the carburetor (I marked their locations).

If any other info is needed, just ask. I can take pictures if needed, also. Thanks for any advice or input.

[frankp]

I just wanted to thank you for the great job on this post. Unfortunally I can't offer any help, But I will monitor this thread carefully. thanks

[38racing]

check the idle speed screw. Maybe you are just letting the throttle close too far to maintain enough fuel/air flow to keep it running. On saturday I helped a friend with his and the carb seemed all clean and it also died when throttle reduced. I did not have time to investigate further but as long as it runs at high speed it's not a big issue.

[wristpin]

I'm not familiar with your engine by model but two things occur to me. I am assuming that in the snow blower application the engine will not have run enough hours to be worn out and past redemption!
Valves. Because it's a bit of a faff doing a valve reseat and re-gap a lot of people spend a lot of time trying to avoid doing a valve job and fiddling about with carburettion and ignition. Bite the bullet and have the valves out, inspect, reseat them and check and set the gaps. Pay particular attention to not over gapping them as it will affect the Automatic Compression Release feature found on most small engines. In the absence of any specific instructions, check the valve gaps with the piston about quarter of an inch down the bore on the power stroke (quarter of an inch past top dead centre). That should ensure that the ACR is not interfering with the correct gapping.
Governor. Again, I'm not familiar with your particular engine but bear in mind that 5 degrees of shaft movement can relate to quite a lot of linear movement at the end of the arm connected to the rod to the carburettor so you may not have upset anything there - (unless,and I don't know whether it is possible on your engine) you have rotated it through 180 degrees. If the gov' arm is free to rotate on the shaft, as opposed to be located on flats, the general rule of thumb is to turn the shaft in the direction that would move the throttle to the full open position - so open the throttle wide, turn the shaft in that direction and clamp it up.

[FortyCaliber]

check the idle speed screw. Maybe you are just letting the throttle close too far to maintain enough fuel/air flow to keep it running. On saturday I helped a friend with his and the carb seemed all clean and it also died when throttle reduced. I did not have time to investigate further but as long as it runs at high speed it's not a big issue.

Hey 38racing. I don't think the throttle plate is getting anywhere near the screw, even when I move the lever down to idle position. I went out again today and messed with it and can't even get it to start. The instructions I found on the net for setting the static governor say to rotate the governor arm all the way clockwise, while holding the throttle plate completely open, and then tighten the screw. I moved the shaft all over the place. I finally got it to run with the shaft turned all the way COUNTER-CLOCKWISE. But, it only ran for about 20 seconds or so.When it dies I immediately checked the bowl for gas and there IS gas in the bowl. I also took the flywheel off to check the key for shearing. The key looked good but there was evidence on the flywheel edge of a prior key shearing. Before I removed the flywheel, I checked the air gap between the CDI and the magnets and a .002 feeler gauge was TIGHT. My service manual says the gap should be .0125. I'm not sure which numbers are correct. I'm not sure where to go from here. Thanks for the input, though.

[FortyCaliber]

Hey wristpin. I agree that there is small amount of hours on this snowblower. But, you know how they make things today.

As far as the valves, I doubt I'm comfortable enough to do that myself. I really don't have the right "special" tools to do that, anyway. I'd have to take it somewhere probably. It might even be cheaper to buy a new motor. It may be the valves. I did have it running, though, for nearly a half hour. See my above post for what I did today.

I definitely did not rotate the governor shaft 180 degrees. If it did rotate that much, it would have had to have been done on its own and I can't see how that could happen. Like I said, when I rotate it with a pair of pliers it only moves a very little back and forth.

Thanks for the advice.

[Merkava_4]

Is this your carburetor in the link below?

http://outdoorpowerinfo.com/repairs/tec ... 632107.asp

[KE4AVB]

Maybe this will help.

I am surprised that the flywheel isn't hitting the coil laminates @.002" open it up to .010 -.0125".

To adjust the governor pay attention as you open up the throttle as to which direction it turns the shaft. With the throttle held at full speed position continue rotating the governor in the same direction until it stops. Be carefully as not push in the governor cross shaft. Tighten the locking assembly. What this does is to take the play in the governor setup.

Now let's start over over on the carburetor mixture setup. Lightly seat both mixture screws. Now turn the high speed out 1-1/2 turns and the idle mixture 1 turn. This will place the carburetor in a preset condition. Try starting the engine if it now starts and runs set the high mixture first and the idle mixture and speed. You want these mixture screws to be half between too lean and too rich. Sometime the high speed may need a little tweaking under load to get it the engine to run smooth.

[FortyCaliber]

I have another question that I hope someone won't mind indulging.

I was looking at the flywheel key. It has a "notch" at one end. For the life of me I can't figure out what this notch is for. I remember when I worked on older motors that there was points cover and a notched key would slide under the points cover. But, my motor has a CDI ignition and therefore no points. There is a nylon bushing on the shaft, but it has it's own integral key that sits on the crankshaft groove and keeps it from spinning. There is no need for this notch in this key, as far as I can tell.

I, also, read on another forum where Sears/Craftsman would use an "offset" key. The information I gathered is that the width of the groove in the crankshaft is different slightly from that in the flywheel. From what I understand this "offset" key somehow alters the timing for some reason.

I guess what I'm getting at is if I have the right key for my engine? It was apparent to me that someone has worked on this before because of the indentations on the edge of the flywheel from a previous key shearing. I just wonder if the right replacement key was installed?

[FortyCaliber]

Is this your carburetor in the link below?

http://outdoorpowerinfo.com/repairs/tec ... 632107.asp

Yes, that looks pretty darn similar. The number is also the same as the one I just bought.