What are your jet specs?

12incher · 03-21-2018, 09:00 PM

I'm curious to see what everyone is running on these 125cc engine. I see everything from 110 to 195 main jet online. I've got a Vm26 carb with a 110 main and 22.5 pilot. Pod filter and stock exhaust. It runs out alright but definitely feels like it needs more fuel. I'll have a jet kit and new exhaust here in the next few days to experiment further.

EastCoastOctane · 03-22-2018, 01:09 PM

I have the same carb on my Razkull, with stock exhaust, If I remember right I'm running a 120 main. still tweaking on mine as well. I had a 125 jet in it, and it would bog in the mid rang when warmed up, it runs better on the 120, but I think I might be a little lean at wot.

Megadan · 03-22-2018, 03:33 PM

Quote:

Originally Posted by EastCoastOctane

I have the same carb on my Razkull, with stock exhaust, If I remember right I'm running a 120 main. still tweaking on mine as well. I had a 125 jet in it, and it would bog in the mid rang when warmed up, it runs better on the 120, but I think I might be a little lean at wot.

If the 125 is better at WOT, try leaning out the needle jet 1 notch (assuming your needle has more than 1 clip position).

wlfpck · 03-26-2018, 09:29 AM

I'm running 130 main and 25 pilot I think. Where are you at? I think altitude will affect it a bit as well.

12incher · 03-31-2018, 10:01 PM

I'm currently running a 22 pilot and 149.5 main on a Vm26 with stock exhaust with pretty good results. Will be throwing in a 155 main when my exhaust gets here

Arcstriker29 · 04-22-2018, 03:51 PM

my 26mm carb came with a 95 main jet, I swapped it out with a 110 and it ran better, however it began acting up once it was warmed up, if I stopped at a light or stop sign, it would want to stall out, it did not like to idle at all. I swapped it out with a 105 and it got a little better, but not as smooth as it was. When it would stall out, it would crank over and over, but wouldn't want to start back up unless I 1/2 choked it, then started up... any advice? I have a 27mm carb coming tuesday and that one looks easier to get to the air/fuel mixture screw, so I'm just waiting on that. But would love to jet this out to a 150 or bigger jet. I'm not too knowledgeable about carbs for say, just been a clean 'em and install them kinda a guy. now that I have a 125cc bike... its everything I can do to get more power lol

Weldangrind · 04-30-2018, 10:42 AM

The general idea is that as the temperature drops, air becomes more dense, therefore requiring more fuel. As the temperature increases and air becomes "thinner", you'll need less fuel. Let's say you're using a 25 slow jet during temperatures above 70F; you might increase to a 27.5 or 30 if it drops to around 32F. Similar logic applies to the main jet.

Arcstriker29 · 04-30-2018, 11:04 AM

Quote:

Originally Posted by Weldangrind

The general idea is that as the temperature drops, air becomes more dense, therefore requiring more fuel. As the temperature increases and air becomes "thinner", you'll need less fuel. Let's say you're using a 25 slow jet during temperatures above 70F; you might increase to a 27.5 or 30 if it drops to around 32F. Similar logic applies to the main jet.

Thank you, I have a better understanding of it now.

wheelbender6 · 05-01-2018, 09:15 PM

My 125cc has a Keihin clone carb. It came with a #90 jet. I jetted up to a #95 when I mounted an aftermarket exhaust.

03-21-2018, 09:00 PM	#1
12incher Join Date: Mar 2018 Posts: 4	What are your jet specs? I'm curious to see what everyone is running on these 125cc engine. I see everything from 110 to 195 main jet online. I've got a Vm26 carb with a 110 main and 22.5 pilot. Pod filter and stock exhaust. It runs out alright but definitely feels like it needs more fuel. I'll have a jet kit and new exhaust here in the next few days to experiment further.
	0

04-30-2018, 10:42 AM	#7
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	The general idea is that as the temperature drops, air becomes more dense, therefore requiring more fuel. As the temperature increases and air becomes "thinner", you'll need less fuel. Let's say you're using a 25 slow jet during temperatures above 70F; you might increase to a 27.5 or 30 if it drops to around 32F. Similar logic applies to the main jet. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
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03-22-2018, 01:09 PM	#2
EastCoastOctane Join Date: Feb 2018 Posts: 5	I have the same carb on my Razkull, with stock exhaust, If I remember right I'm running a 120 main. still tweaking on mine as well. I had a 125 jet in it, and it would bog in the mid rang when warmed up, it runs better on the 120, but I think I might be a little lean at wot.
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03-26-2018, 09:29 AM	#4
wlfpck Join Date: Mar 2018 Posts: 249	I'm running 130 main and 25 pilot I think. Where are you at? I think altitude will affect it a bit as well.
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03-31-2018, 10:01 PM	#5
12incher Join Date: Mar 2018 Posts: 4	I'm currently running a 22 pilot and 149.5 main on a Vm26 with stock exhaust with pretty good results. Will be throwing in a 155 main when my exhaust gets here
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04-22-2018, 03:51 PM	#6
Arcstriker29 Join Date: Mar 2018 Location: New Hampshire Posts: 34	my 26mm carb came with a 95 main jet, I swapped it out with a 110 and it ran better, however it began acting up once it was warmed up, if I stopped at a light or stop sign, it would want to stall out, it did not like to idle at all. I swapped it out with a 105 and it got a little better, but not as smooth as it was. When it would stall out, it would crank over and over, but wouldn't want to start back up unless I 1/2 choked it, then started up... any advice? I have a 27mm carb coming tuesday and that one looks easier to get to the air/fuel mixture screw, so I'm just waiting on that. But would love to jet this out to a 150 or bigger jet. I'm not too knowledgeable about carbs for say, just been a clean 'em and install them kinda a guy. now that I have a 125cc bike... its everything I can do to get more power lol
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05-01-2018, 09:15 PM	#9
wheelbender6 Join Date: May 2015 Location: Houston area Posts: 1,902	My 125cc has a Keihin clone carb. It came with a #90 jet. I jetted up to a #95 when I mounted an aftermarket exhaust. __________________ "Its not WHAT you ride; its THAT you ride"
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