Nibbi 26mm on Venom x20

mjmi11er · 04-19-2021, 08:14 PM

So I've replaced the stock carb and intake with Nibbi parts. I started with the air fuel screw 1 turn out and the fuel screw knob 2 turns out per the video on YouTube of the a guy tuning this carb on his mini dirt bike. With the 40 pilot the bike will immediately start without the choke and run without issue and has a crisp throttle. Everything else seems to be an issue though. Way to rich under throttle. With a 100 main jet it was bogging almost immediately. I've worked my way down to a 75 main with the needle all the way down. It still requires a smooth throttle and it starts bogging around 8k. The plug is also way too dark with a chop test. I ordered some 60-70 main jets to try to go leaner... or am I missing something?

Should I start over adjusting the screws with a smaller pilot in place first?

I just haven't heard anyone running a 40 pilot and 65 main.

What am I missing or doing wrong?

RustyJames · 05-09-2021, 05:11 PM

I'm in near the same place after trouble get home few days ago switched carburetors couldn't passed 6000 rpms and after throttle cable adjustment got to 8000 rpm and climbed the hill to my driveway
But it's still not rite Think my trouble started with h a bit of rain water in the gas tank making it bog and difficult to start
(Gas cap can look closed but not sealed )
It's raining today so tomorrow morning I adjust throttle cable again then set the air fuel mix I'm still using the slide carburetor
And switching to a performance carburetor
I have noted some dust around one of hoses Which could have made this a 2 trouble issue I'm about to clean up this back up carburetor Seems a contingency
A good idea to have ready to go
I'm sorry I can't be of more help
But very interested how this turns out

mjmi11er · 05-11-2021, 07:12 PM

As of now I have the Nibbi 26mm and a Nibbi intake. The pilot is a 40 and the main is a 90. The needle is all the way down.

It runs strong up to 65mph with more pull at redline then before.

The filter right now is just a cotton cloth with a zip tie until i can find a filter small enough to fit on the front of the carb that won't be hit by the forks when turning. So I have to continue monitoring that and make sure it doesn't rip or it runs terrible.

I'm also going up a tooth on the front sprocket. Will report back after some more trials.

mjmi11er · 05-22-2021, 03:19 PM

I finally found a 26mm K&N that is short enough to mount directly to the Nibbi.

After a couple hours messing around with the jets I settled on a 110 main and a 40 pilot, needle is all the way down.

04-19-2021, 08:14 PM	#1
mjmi11er Join Date: Dec 2020 Posts: 9	Nibbi 26mm on Venom x20 So I've replaced the stock carb and intake with Nibbi parts. I started with the air fuel screw 1 turn out and the fuel screw knob 2 turns out per the video on YouTube of the a guy tuning this carb on his mini dirt bike. With the 40 pilot the bike will immediately start without the choke and run without issue and has a crisp throttle. Everything else seems to be an issue though. Way to rich under throttle. With a 100 main jet it was bogging almost immediately. I've worked my way down to a 75 main with the needle all the way down. It still requires a smooth throttle and it starts bogging around 8k. The plug is also way too dark with a chop test. I ordered some 60-70 main jets to try to go leaner... or am I missing something? Should I start over adjusting the screws with a smaller pilot in place first? I just haven't heard anyone running a 40 pilot and 65 main. What am I missing or doing wrong?
	0

05-09-2021, 05:11 PM	#2
RustyJames Join Date: Apr 2021 Location: Kentucky Posts: 12	I'm in near the same place after trouble get home few days ago switched carburetors couldn't passed 6000 rpms and after throttle cable adjustment got to 8000 rpm and climbed the hill to my driveway But it's still not rite Think my trouble started with h a bit of rain water in the gas tank making it bog and difficult to start (Gas cap can look closed but not sealed ) It's raining today so tomorrow morning I adjust throttle cable again then set the air fuel mix I'm still using the slide carburetor And switching to a performance carburetor I have noted some dust around one of hoses Which could have made this a 2 trouble issue I'm about to clean up this back up carburetor Seems a contingency A good idea to have ready to go I'm sorry I can't be of more help But very interested how this turns out __________________ 2021 Jiangsu Baodiao BD12511GTX18 In a car you're always in a compartment, and because you're used to it you don't realize that through that car window everything you see is just more TV. You're a passive observer and it is all moving by you boringly in a frame. On a cycle the frame is gone. You're completely in contact with it all. You're in the scene, not just watching it anymore, and the sense of presence is overwhelming
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05-11-2021, 07:12 PM	#3
mjmi11er Join Date: Dec 2020 Posts: 9	As of now I have the Nibbi 26mm and a Nibbi intake. The pilot is a 40 and the main is a 90. The needle is all the way down. It runs strong up to 65mph with more pull at redline then before. The filter right now is just a cotton cloth with a zip tie until i can find a filter small enough to fit on the front of the carb that won't be hit by the forks when turning. So I have to continue monitoring that and make sure it doesn't rip or it runs terrible. I'm also going up a tooth on the front sprocket. Will report back after some more trials.
	0

05-22-2021, 03:19 PM	#4
mjmi11er Join Date: Dec 2020 Posts: 9	I finally found a 26mm K&N that is short enough to mount directly to the Nibbi. After a couple hours messing around with the jets I settled on a 110 main and a 40 pilot, needle is all the way down.
	0