Bike will run, but won't idle

B

BLKGLD

New Member
Hey everyone. first build here. it will run when i pedal and bump jump it but when I go to stop and pull in the clutch, it revs high, but want to keep moving?
please tell me what I'm doing wrong!!! Thanks!!!! Also, it wont climb slight inclines. I bought this to learn more about engines, so I dont know much and am unsure how to search this & I've come up empty handed :(
 
I assume that you already have tried adjusting the idle speed screw.
First guess in an air leak between the carb and manifold or manifold to cylinder.
This would affect the air to fuel ratio greatly and explain why the engine does not have enough power to climb slight inclines.
Second guess is the carburetor's slide is installed backwards.
Third guess is the throttle cable is adjusted too tight or binding inside the cable housing.

How much pre-mix oil are you adding to the gasoline to create the fuel?
 
Thanks for the response! I tried the idle speed screw. I will check to make sure the carb and manifold are fixed properly. I will take apart te carb again and check that too. An te throttle. The ratio I am using, for break in, is 20:1. Should I change it? I know it needs to run a while for break in but I can't seem to do that until it will idle. Thanks man!
 
Assuming that you are using regular petroleum pre-mix and not synthetic, 24:1 would be better for break in. Switch to 32:1 after the first 4 tank fulls or 2 gallons, whichever comes later.

Don't forget to check every single fastener on the whole bike for proper tightness, especially the cylinder head bolts for proper torque as the engine breaks in.
This does not mean tighten them every check. If they are loose then tighten them to 120 to 140 INCH pounds for 8mm studs/ 60 to 80 INCH pounds for 6mm studs. (An inch pound torque wrench is a very good tool to own.)
Determining which cylinder studs your engine has is critical here. For a size reference, the engine mount studs are 6mm.
This will help prevent blown cylinder head and base gaskets, engine mounts that mysteriously dissapear and a bicycle that rattles apart.

Over time everything will settle in and only a few nuts and bolts will require tending to regularly. The machine will let you know which ones they are.
 
Carb to manifold was a little loose. But the real culprit was the throttle cable. Thanks! She screams now!
 
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