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Tecumseh MH80 - cleaned bowl and jets but have a little problem


Jack Flash's Avatar
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12-17-07, 04:07 PM   #1  
Tecumseh MH80 - cleaned bowl and jets but have a little problem

When I lowered the bowl to clean it a small metal piece dropped out. It is only the size of the tip of a pencil and is 1/8 inch long with a point. It also has a small hinge like rod attached to it. I can see where the pin goes - up into the carb when the bowl trap is closed. My question - where does this piece attach to? How?

I have cleaned the bowl and jets out before and this piece was never an issue.

 
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12-17-07, 06:45 PM   #2  
Sounds like the tip of the needle broke off, or the needle itself fell out. The needle is attached to the float with a small metal clip and the needle slides into a small orifice in the carb body and the whole lot is held in with that small metal rod. Generally it (IMO) is not a good idea to remove the float bowl with the carb on the engine because this sort of thing can happen. If my assumption is right, It is probably the part #525402 at this link:
http://www.jackssmallengines.com/carb_parts_t.cfm
Let me know if this is it.

 
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12-18-07, 03:52 AM   #3  
Yes Sir, That's the part. The needle did not break. It fell out of the orifice. And see the part just below it with the rod (631021B)? I have the that rod (hinge) attached to the needle. I see the orifice the needle goes into but how/what/where do I attach the rod (hinge) to that holds the needle in place?

I see the small O-rings or gaskets with the parts. They are either still in place or they are lost on the garage floor.

 
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12-18-07, 03:54 PM   #4  
I am guessing you're calling the wire retainer clip the hinge/rod? If so, that piece clips onto the needle, and clips onto the tab on the float. It pulls the needle down when the float drops.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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12-18-07, 05:28 PM   #5  
Oh, I see. I'll try to find where it clips on to in the morning light.

Thank you, Cheese

 
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12-19-07, 03:42 PM   #6  
Thank you again. I found where it clips on the tab and it is working fairly well. Poor design though if you ask me. My machine is 20 years old. I hope some engineer has designed a better way to hold that needle in place.

I think I got the main mixture screw set correctly but the other two screws have me stumped. I got it working but it is not quite right. The RPM is too high and overall it just doesn't sound right. Does anyone have a 1-2-3 (or more) system for adjusting these screws so it runs smoother?

 
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12-19-07, 10:40 PM   #7  
Get it to idle speed, then set the air-fuel mixture screw (the one on the side of the carb). It is usually best at around 1 1/2 turns out from lightly seated. Then set the idle screw (top of the carb) to set the rpm desired. Mixture screw may need tweaking after this. Then set the high speed mixture screw at the bottom of the carb. Run the engine at full throttle, and back the screw out until the engine begins to stumble, then turn it back in while counting the turns until the engine begins to die and surge, then divide the number of those turns by 2 and back it out that much. This should get it set right.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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12-20-07, 05:05 PM   #8  
Cheese, you're good.

It now runs better than ever.

Thank you, and Legal v8 too.

 
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12-21-07, 12:39 AM   #9  
Glad we could help!!


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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