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calvynandhobbs

110cc moped not sucking fuel

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I know there’s someone on here that messes with the Honda 110 bikes. I started working on my yumbo 110cc Honda knock off. I can get it to start on starting fluid. I replaced fuel lines and filter. Inside the tank looks good. I read on a moped forum about a tappet or something like that for the vacuum to such gas. Or am I looking at a carb issue? 

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Edited by calvynandhobbs

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Pull fuel line, verify gravity flow.  

 

Pull carb, pull float bowl and float, look at needle and seat. You probably lost a wire clip that pulls the needle open when float bowl is low. SS Guitar string works great.  

 

Does this thing have a little box in the fuel line thats got 3 hoses attached?  

 

2 stroke or 4?

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4 stroke and fuel runs through to the carb free flowing. I’ve been googling pictures of 110cc carbs and I think I spotted a vacuum line to the intake manifold that may be missing. When it quit it was all of a sudden. I down shifted going down a hill and it died. I wonder if I blew that vacuum line off.

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  If it is a "CV" carb it will need vacuum signal.  

 

That is not.  Theres no reason for a vacuum line, any port nipple on that will be a vent or overflow afaik. 

Edited by mike_belben

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Does the fuel petcock have a vacuum diaphragm to operate the fuel on/off?  That could be what the vacuum line operates.  I also had a chicom 110 kids wheeler that had some kind of evap system on the fuel tank and breather.  Had some kind of pcv set up that pulled fumes from the tank vent.  It was troublesome and eventually was removed...ports plugged.  Went up on the jets sizing in the carb and the thing ran better than ever.  Also check compression the valve lash on these is minimal and when they get some wear the valves hang open a bit and cause low compression, hard starting etc.

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37 minutes ago, POS_YJ said:

Does the fuel petcock have a vacuum diaphragm to operate the fuel on/off?  That could ne what the vacuum line operates.

That's what I'm thinking. I know there is a fuel tank vent line, there's another vent line hanging off the side of the carb and there's another line that's hanging currently. I need to pull the carb and see if there's a nipple somewhere on it or the intake that is open. I may get a chance to get back out there tonight after I drop off bricks.

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The diaphragm operated petcocks don't have an off position.  They usually have an on, prime and reserve with a vacuum nipple off the back.

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18 minutes ago, heavysquad said:

Is the carb supposed to point forward like that?

Yes, the little black plastic piece laying between where I was standing and the bike is the air cleaner assembly that mounts to the front of the carb and onto the frame of the bike as it goes toward the handle bars.

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I'm with the Belbenator. Floats always seem to be an issue with small engines.

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it's weird that it stopped dead, and will now only run on starting fluid. Usually carb issues develop from sitting. I guess, clean the carb and and make sure you're giving it fresh clean fuel.

 

I don't know about "modern" engines, but, the honda 110 I have and the 90cc and 140cc knock offs do not have vacuum actuated petcocks. 

Edited by heavysquad

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28 minutes ago, heavysquad said:

it's weird that it stopped dead, and will now only run on starting fluid. Usually carb issues develop from sitting. I guess, clean the carb and and make sure you're giving it fresh clean fuel.

 

I don't know about "modern" engines, but, the honda 110 I have and the 90cc and 140cc knock offs do not have vacuum actuated petcocks. 

The stopping dead while driving 20mph is what throws me off. Maybe it is still something electrical that went, but it's not getting fuel except for the starter fluid and cranks right over on it. Hopefully I can pull the carb off tonight and go through it.

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Step1.. Manually fill the float bowl through fill port hose with a syringe or whatever.. See if it runs.  We need to determine if the issue is in the carb or before it.  

 

Vacuum petcawks are terrible.  So are dirt daubers in your vent lines. Punch em out with some fence wire.

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