Black Ox carb problems

J

Jim C

Member
My Black Ox is a 29 inch cruiser with a HS 49 cc motor in it. The continuing problem is the bike will start on full choke but will not run otherwise. I have removed the carb and found no dirt or plugged up jets, float is ok and it all looks good. My instinct tells me this is a problem with the carb but I can't find anything wrong there. This build has less that 50 miles on it. Looking at the spark plug tells me very little. It is sooty but running full choke it would be. I can't be the only one with this problem. How did you remedy it?
 
Jim C said:
My Black Ox is a 29 inch cruiser with a HS 49 cc motor in it. The continuing problem is the bike will start on full choke but will not run otherwise. I have removed the carb and found no dirt or plugged up jets, float is ok and it all looks good. My instinct tells me this is a problem with the carb but I can't find anything wrong there. This build has less that 50 miles on it. Looking at the spark plug tells me very little. It is sooty but running full choke it would be. I can't be the only one with this problem. How did you remedy it?
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Only 50 miles? If you let gas sit in those carbs they plug up really easy.

Changing the carb out to an easily maintained 2 stroke type is one solution.
This needs a new intake manifold.
I can help you out if you want to do this locally.
 
-what is your ground level altitude? (these engines are set up to run near to sea level if your altitude it much higher than that you will need to re-jet the carb)

-what is your areas average temperature? (if you happen to live in Alaska or on a mountain your engine probably just needs re-jetting like i said above, but also will need a good warm up before it can run properly)

you also may want to give a visual inspection on your choke by removing the air filter, there may be some damage to the choke itself causing this (i.e. a misaligned choke plate could cause 'full choke' to not actually be full choke, and 'choke off' to be more choked or something to that effect, easy to fix if that's the problem.)
and finally have you tried fiddling with the fuel adjustment screw? this thread is discussing how to gain access to the fuel adjustment screw

edit: oh also if you have less than fifty miles on it it may just need breaking in, i have about the same run time on mine and I have already noticed that it is starting easier. what I'm saying is that small motors really pick up after they finish breaking in. you issue may just be tight tolerances and being set too lean combined, so a little fiddle with the fuel screw, and some more miles on it may solve your problem. I say for step one look at your choke plate to make sure it's good. if that's not the problem then try the fuel adjustment screw, if that doesn't help you may need to look into a new jet or even new carb.
 
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GoreWound said:
-what is your ground level altitude? (these engines are set up to run near to sea level if your altitude it much higher than that you will need to re-jet the carb)

-what is your areas average temperature? (if you happen to live in Alaska or on a mountain your engine probably just needs re-jetting like i said above, but also will need a good warm up before it can run properly)
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It says where he lives on everyone of his posts.
Long Beach Calif
Posts: 169
That would be sea level and warm..........
 
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