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8HP B&S Engine issues on TB Tiller


boxtwo's Avatar
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08-16-17, 04:14 AM   #1  
8HP B&S Engine issues on TB Tiller

Hi all! I have been searching for a resolution for several days and have not had success resolving my issue.

The details
New to me Troy Built Horse Tiller (Likely a Horse 3, SN 573211)
Briggs 8HP engine Model: 195432, Type: 0149 01, Code: 8108111

The issue:
--It started and ran (no-load) post carb rebuild. (All cleaned, float level)
--It leaked gas from the weep hole and 7/16 nut at bottom of intake elbow.
--Removed carb again, replaced jet, checked and cleaned needle and seat, checked float, and adjusted float to non-hinge side slightly elevated.
--Installed everything again, leaked fuel again as before, it never started or even sputtered. Plug dry.
--Pulled carb again, adjusted bowl towards level a bit and tried again. No fuel after a dozen pulls.
--Removed jet valve screw, no fuel leaking. Pulled fuel line, lowered, fuel flowed, reattached to carb.
--Tested spark= OK (new JC8 plug at .030)
--More pulls, leaking fuel from weep hole again, not as badly. Removed jet valve screw, fuel leaked. Tried starting, wouldn't.

I have done nothing other than remove and rebuild the carb after it started an ran. I am at a loss as to what this could be other than a fuel issue. Spark OK, air filter OK.

Thoughts on what else to try? Thank you!!!

 
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08-16-17, 07:36 AM   #2  
Set the carb float at level when up. Hold light pressure up on the float with gas on. About what you could push at the end of a pencil held horizontal. The pressure should shut off the flow of gas. If it does the gas at the weep hole is likely from choking when trying to start.

That being the case, shut off the gas to the carb or disconnect the gas line. Take out the plug and with no choke, full throttle spin it over a few times to purge the engine of gas fumes. Check for gas in the oil, but the weep hole should have prevented that.

Then stick the plug back in and with half choke, full throttle see if it will fire. It may take a few pulls. When it does (hopefully), turn the gas back on and see if it will take off for you.

 
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08-16-17, 07:49 AM   #3  
Thanks marbobj. So I understand correctly, with the carb in half, attach fuel line, hold below level of fuel tank and turn on fuel to check float. That will determine whether the float and needle is functioning properly, correct?

Then turn off gas, pull plug, turn over via pull cord. Reinstall plug, 1/2 choke, full throttle, try again.

With a dry plug after all this, it seems as if no fuel is even making it to the motor, despite it free-flowing from the bottom of the emulsion tub when I remove the needle adjuster.

 
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08-16-17, 11:03 AM   #4  
I would guess, with gas coming out of the weep hole you may have it flooded. A good start is to check the float/float valve. Then purge the engine combustion chamber.

First make sure the float is working the way you just described.

 
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08-16-17, 11:10 AM   #5  
Thanks! In doing a bit more research, it sounds as if fuel level may come into play. As fuel tank level, filter placement, line angle/length, etc. I know the fuel tank has less than 1/2 in it. With a dry plug that makes some sense.

OK on instructions above. What's the purpose of "purging" though?

 
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08-16-17, 11:51 AM   #6  
Don't get too concerned about a dry plug. Fuel ignites off the vapors, not the liquid. Purging is to get the vapors out and back to a start condition, if there is a flooded condition. It's like starting over.

All you need is a float bowl full of fuel to start the engine.

 
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08-16-17, 01:42 PM   #7  
Fires with fuel in plug hole then dies. I can pull the needle at the base of the emulsion tube and there is no fuel coming out.

 
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08-16-17, 02:16 PM   #8  
You checked for fuel flow/shut off at the float valve and the float at lowered got a good fuel flow, then shut off with light pressure up on the float? With that did the float bowl go on without any problems. Sounds like you aren't getting any fuel in the bowl. Was it full when you removed it?

It all acts like your float isn't working to allow and shutoff the fuel when the bowl is in place. Double check the pin that mounts the float and the travel in the float up and down.

 
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08-17-17, 01:22 AM   #9  
I pulled the carb AGAIN with the fuel line still attached. Rattled, no noise inside. Tapped carb, no change and no fuel. Pulled apart with fuel line still attached and found that the float is binding inside the carb AND that I can no longer adjust it towards level any more (NO idea why, as nothing inside has changed.)

This explains: why no fuel and why flooding. Something is borked with the float and needle valve.

I also broke the aluminum packing nut for the emulsion tube...a little too much wrench. Easy fix and the broken stem came right out. Sifting through the trash can to find the old one was a bear...but I found it! I'll take another stab at it later today.

Thank you for your help so far!!!

 
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08-21-17, 08:45 AM   #10  
FIXED!!!

The float needed to be adjusted. That was it. Once done correctly, it fired on the second pull.

Thanks for the help!

 
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