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Discussion Starter #1
Ok I got the new starter yesterday and tried to start the horse but now no spark. Not sure how to test the individual components to figure out which is the culprit. I have a '71 work horse 800 with an 8 hp tecumseh with solid state ignition. Any ideas?
 

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I'm not overly familiar with Tecumseh engines, but on a Briggs (I'm assuming they are relatively similar) the first thing I would check would be if the flywheel magnet has rust on it, and probably clean it anyway. Then I'd clean the contacts on the magneto (armature) and check the gapping. Third, spark plugs are cheap, just go and replace it.

Hope this helps!
 

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Discussion Starter #3
Do you know how much gap btween the mag p/u and the fly wheel?
 

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A Google search led me to believe that the proper air gap between the armature and flywheel should be .008". I have a Tecumseh book somewhere and if I can get my hands on it I'll double check for the proper gap specs.

I usually cheat with Briggs engines and use a business card or a cutout from a flash card. Does the same and never has failed me. Just make sure it isn't too tight. If you tear the card or struggle to remove it, then it's too tight.

Good luck!
 

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Discussion Starter #5
Thanks ge-off. I'm gonna go out and check that now and see where it's at. I don't understand what happened. I got the tractor 2 weeks ago and it ran fine and now this, just my luck I guess lol
 

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Before purchasing anything, you should also try removing the spark plug from the cylinder head, leave it plugged in, and make sure the tip is touching something metal. Carefully spin the flywheel, either by hand, with the pull start or electric start, and see if you're receiving any kind of spark. If there is no spark, the spark is intermittent, or is orange, first thing I would try is replacing that spark plug. There should be a nice crisp blue spark coming from the spark plug. Also, check the connection in the spark wire to make sure it is not rusted up or corroded (clean if necessary with a file). Then I would disassemble and clean the armature and/or flywheel with a wire brush and check the air gap.

You might also want to check to see if the engine has been running too rich. If there is excess carbon on the spark plug (black color, caked -- the spark plug has fouled), I'd replace the spark plug and think about removing the head to clean the inside of the chamber. When you remove the head, take a razor blade and gently scrape the top of the head free from any carbon build up (trying not to leave any gouges or deep scratches). If there is a build up on top of the piston, valves, and firing chamber, do the same -- make sure the piston is at the top of the firing chamber and the valves are shut before cleaning. Do not scratch the cylinder walls! It might not hurt to check this anyway, especially with the age of the engine and how it was treated before you. Of course, adjust the carburetor to resolve this issue, if necessary.

If that does not resolve the issue, you may have a more costly repair, such as a faulty armature or coil.

Good luck -- I hope I'm not preaching to the choir.
 

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Discussion Starter #7
You've been a big help! I checked the gap for the mag p/u and cleaned the plug. It is firing outside the cylinder now, nice hot spark. I can't get it to fire up the engine though. I think it is running rich, I will get a new head gasket and de-carbon the combustion chamber put in a new plug (BTW: is an R8C plug correct?) I also need to fine out how to go about adjusting the carb. I'm not used to small engines but trying to learn fast. lol. I also have to send the new starter back, it's been on for 24 hours and already giving me problems. GRRR
 

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If you have ever worked on larger engines, single and dual cylinder engines are simple in design. However, they have their own quirks. Pardon if I write as if you don't know what you're doing -- I like to be as thorough as possible to help you understand my point(s).

You only need three things to run:
1. You've got spark (blue and true).
2. You've got fuel (possible flooding/rich).
3. You've got air (I'm assuming its not restricted).

Since you think it is running too rich to ignite the air/fuel mixture, I'd recommend proceeding with the following:
1. Take the air cleaner assembly off of the carburetor so you can see into air intake of the carburetor assembly. When you try starting with choke, can you see gasoline spewing out? If so, it's flooding. Does this occur without choke? If so, then it is receiving too much fuel. If not, there could be a clog in the fuel line (filter), or worse the carburetor -- you may wish to take it apart and give it a thorough cleaning/possible rebuild.

2. If you're receiving too much fuel without choke, I recommend taking note of how far the main fuel jet on the carburetor is turned out. You can achieve this by taking a flat screw driver and turning the jet clock-wise (in). Keep track of how many turns by counting half turns. Screw it in as far as it will go, but do not snug it down/turn too tight -- this could cause damage to the seat and needle. Once you have your marking (let's assume it is 2.75 turns), turn it back out to it's original setting. This will give you a point of reference so if the following does not work, you can put it back into the setting you started with -- one you know has worked in the past.

Now, turn it clock-wise, a quarter turn at a time, and try starting. Eventually, it should begin to flutter and fire right up (assuming you haven't fouled out the spark plug from flooding -- you may need to wait after each attempt for the flood to dissipate).

3. Once you have it running, there is a method of finding the carburetor's "happy place" (as I like to call it). In it's running state, let it warm up without stalling and run at full throttle. Then, take the main fuel jet and screw it in until it starts to flutter as if it wants to stall. Now, back the jet screw out until it does the same. Note how many turns there are between these two points. Smack in the middle should work fine (it did on my Wheel Horse).

4. Now, turn back the throttle to an idle position and set your idle. This screw should be on a piece that pivots on top of the carburetor. It has been my experience with Tecumseh engines that you may want to keep this turned up higher than normal, especially for cold and/or damp weather (they are temperamental, like Holley Carburetors for cars).

I hope this helps. If i have made an error, please someone else provide some input. This is my method and it "usually" works -- although I've got a stubborn Snapper that has carburetor issues.

Good luck!
 

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That 0.008 sounds too close for the gap.
I thought it would be around 0.025....but that
is just a thought and not a fact.
I can't locate my Tecumseh book, but depending on the series engine for Briggs, the gap can be anywhere from 0.006" to 0.014". I would guess there could be a similarity? A thick business card or a flash card should still do the trick.
 

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I can't locate my Tecumseh book, but depending on the series engine for Briggs, the gap can be anywhere from 0.006" to 0.014". I would guess there could be a similarity? A thick business card or a flash card should still do the trick.
This should help significantly: http://mytractorforum.com/showthread.php?t=15309

I've got this book "somewhere" and I can't put my fingers on it.
 

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Discussion Starter #12
I tried to set the main mixture screw, a freind said to try it at 1 1/2 turns from the seat (this is the screw at the bottom of the carb bowl right?). It seems to be flooding but I have to get the starter issue sorted so I can proceed. There is another adjuster screw I beleive for the idle air mixture? Where should this be set? BTW: Don't feel bad about being thorough, I don't know much when it comes to small engines. I know the basic concept but not much experience hands on. Thanks again for the help.
 

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There is a good manual in the MTF's Reference Library

8 to 18 tecumseh cast iron engines It has all the info you need.

Both screws are about 1 1/4 to 1 1/2 from seat. Don't over tighen the screws just lighty seat them.
 

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I tried to set the main mixture screw, a freind said to try it at 1 1/2 turns from the seat (this is the screw at the bottom of the carb bowl right?). It seems to be flooding but I have to get the starter issue sorted so I can proceed. There is another adjuster screw I beleive for the idle air mixture? Where should this be set? BTW: Don't feel bad about being thorough, I don't know much when it comes to small engines. I know the basic concept but not much experience hands on. Thanks again for the help.
What is the starter issue you're having?

Does the tractor have an alternative pull start? Pain in the rear, but it's a great backup measure -- Always came in handy on my go-kart while growing up when the battery went bad.

As for the idle mixture setting...I can't help. I'd probably do that by ear until it sounded right for me. I can't really explain it. Refer to the link I gave you before for further details in that regard. :fing32:
 

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Discussion Starter #15
The starter issue I was having was the original starter went out.I ordered a new one from the web, It is junk, I was cranking the motor and the shaft inside the gear on the starter was smoking so it's getting sent back. I found a place in FT. Wayne, In. that is rebuiding the original for me. Once I get it back and if I am satisfied with it I will post there name and contact info. for anyone who may want there original starter rebuilt rather than these cheap after market peices.
Now I am back to having touble getting consistant spark. With the pug out and grounded on the block when I crank the motor it will spark 2 maybe 3 times then nothing more. I don't understand why it would do this. Any ideas anyone?
 

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Now I am back to having touble getting consistant spark. With the pug out and grounded on the block when I crank the motor it will spark 2 maybe 3 times then nothing more. I don't understand why it would do this. Any ideas anyone?
Does it have a solid state ingnition ?
 

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Ok, I see you say it is on your first post.

They can act like this when going bad. Work not work. One thing you can try is unhook the kill wire to see if that gets better spark. You could have a short, bad key switch, solid state going bad.

I have no horse, but lots of old Tecumseh's, so I been there.
 

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Discussion Starter #18
Yes it's solid state ignition. The kill wire, is that the black one hooked to the coil? If not which is it. I'm new to small engines but trying to learn fast.
 

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Yes it's solid state ignition. The kill wire, is that the black one hooked to the coil? If not which is it. I'm new to small engines but trying to learn fast.
There's only two wires from the coil - the big spark plug wire and a smaller black kill wire. When the smaller black wire is connected to ground it prevents any spark from going up the plug wire.
 

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Discussion Starter #20
Ok, I did try disconnecting that small black wire and no spark at all then.
 
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