Mikuni Carb/fuel delivery issue

Mini Bike & Go-Kart Parts

#41
Oh wait
This is a 22mm?
Do you really need a fuel pump for that?
I have several engines with 22mm and use gravity feed and no issues.
 
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#47
I ran into the same issue using Chinese carbs….float needle sticks…no rhyme or reason….just tapped on the bowl before start up and seems fine….
 
#49
dumb question; isnt the tube coming out of the valve cover a breather???

wouldn't plugging the breather up with a fuel pump defeat the pressure
control for the crankcase???
 
#51
dumb question; isnt the tube coming out of the valve cover a breather???

wouldn't plugging the breather up with a fuel pump defeat the pressure
control for the crankcase???
I plan on buying a billet side cover down the road later this month or next month. That will provide the breathing that I need.
 
#54
i have to wonder if using the breather pressure blew out his fuel pump diaphram! the vacuum signal from the
manifold is pretty mild compared to the air pressure and volume displaced by the piston.
 
#55
i have to wonder if using the breather pressure blew out his fuel pump diaphram! the vacuum signal from the
manifold is pretty mild compared to the air pressure and volume displaced by the piston.
the pump is working now... I just have a tuning problem. I runs hard on choke and cuts out off choke.
 
#57
Ok what jets are you running? Do you have extras? You’ll need to change out the jets, adjust the air and fuel etc….do a search there’s a guide out there that explains it perfectly…ian Williams is the gentleman’s name
 
#58
dumb question; isnt the tube coming out of the valve cover a breather???

wouldn't plugging the breather up with a fuel pump defeat the pressure
control for the crankcase???
Thank you.
All internal combustion engines build pressure in the crankcase. I have suggested this before, but always get the same response: other people are running it off the crankcase or valve cover and they are fine.
No one will just try the intake and see if it works better.
 
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#59
Ok what jets are you running? Do you have extras? You’ll need to change out the jets, adjust the air and fuel etc….do a search there’s a guide out there that explains it perfectly…ian Williams is the gentleman’s name
I'm running a 130 main and a 16 pilot. I just bought the mikuni kit off of gps and alot of people I talked too recommended it.
 
#60
Thank you.
All internal combustion engines build pressure in the crankcase. I have suggested this before, but always get the same response: other people are running it off the crankcase or valve cover and they are fine.
No one will just try the intake and see if it works better.
Honestly Im happy with the way it running now. Fuel is pumping finally working and im not trying to re-arrange anything right now. Also I don't want to try and drill out my manifold just to try something that may be a little bit better.
 

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