Go With A 24mm Or Even A 26mm With A 131cc Engine. The 24mm Will Give You Good Top End Performance Without Hurting Bottom End To Much. The 26mm Will Give You Great Top End Performance But Will Lug A Little On The Bottom.
24mm or 26mm for ported head?
I just learned over that I'll be getting a port and polish on my pitster.
My plan was
-cam (probably G2)
-131 kit
-24mm carb
Now with the head work will I really be able to get more benefit from a 26er?
I'm looking at setting the thing up for decent race use, supermoto mainly. Top end appreciated.
My plan was
-cam (probably G2)
-131 kit
-24mm carb
Now with the head work will I really be able to get more benefit from a 26er?
I'm looking at setting the thing up for decent race use, supermoto mainly. Top end appreciated.
1 - 20 of 24 Posts
Get the 26. It will be perfect
i just bought a 26 mm mikuni for my lifan 138 and im having a little trouble jetting it. anyone know about what size pilot and main i should use???
Okay, now I just read a thread on a pitbike class being introduced for 07 in my area. Max 125cc!
26mm ok for 125 HC piston, cam, port?
Which 26mm by the way? I'm seeing a few around.
26mm ok for 125 HC piston, cam, port?
Which 26mm by the way? I'm seeing a few around.
It'll probably be a couple months before I really start messing with anything, I just want to get a strong versitile setup. This state is just starting to mainstream pitbikes so the regs are all over the place.
This is what I get for leaving Cali.
This is what I get for leaving Cali.
Vm26 the oko is much lower quality and harder to get dialed in
The Mikuni Vm Series Carbs Are Very Good. I Have 2 Different Ones, A Methanol 22mm And A 26mm For Gas. Didn't Have To Change Much Out Of The Box On The Gas Setups.
How about 125HC pistons? What's the better brand?
Thanks
Thanks
26mm carb will be prefect, NEVER EVER Run a 28mm carb never!!!!!!!!!!!!!!
ibmike13 said:26mm carb will be prefect, NEVER EVER Run a 28mm carb never!!!!!!!!!!!!!!
I really don't understand how 28mm worth of carb would even flow through stock GPX valves. I'm suprised the 26 gets such good reviews.
ibmike13 said:26mm carb will be prefect, NEVER EVER Run a 28mm carb never!!!!!!!!!!!!!!
Why do you say NEVER run a 28mm carb?
anybody trying to make a gpx go fast with the stock head is wasting their time,and putting a 26mm carb on a head that has a 23mm intake valve is a joke.
Seems like it would be, but I keep hearing good reviews on it. Do you have backup besides "My cousin-in-law who's a genius said..."dragndave said:anybody trying to make a gpx go fast with the stock head is wasting their time,and putting a 26mm carb on a head that has a 23mm intake valve is a joke.
Trying to put the big block through a small hole, yes, we're not talking about blocks though either, air compresses, I don't know how much. I'm trying to figure it out.
i have over 6 hours into my vm 26mm. trying to get it jetted right for my lifan 138 =( !!! a pro, mech and i tried every combo of jets made for it and still no dice. wish i would have bought the 24 mill.....its just to big for my motor,and they advertise it to work w/110cc motors ????????
Wheelspeed831 said:i have over 6 hours into my vm 26mm. trying to get it jetted right for my lifan 138 =( !!! a pro, mech and i tried every combo of jets made for it and still no dice. wish i would have bought the 24 mill.....its just to big for my motor,and they advertise it to work w/110cc motors ????????
So, by 138 is that one of the misstamped 128s? Still, I'd think that's enough to use a 26er, the valves should be way bigger than my GPX.
G
With the pressure differential that engines create, air acts like an incompressible fluid for most of its journey through the intake tract.sibo said:air compresses, I don't know how much. I'm trying to figure it out.
Don't run a carb a lot bigger than your valve. It's a matter of velocity. That's why carbs have ventures. They decrease the area to increase the velocity. An increase in velocity across the jets increases the pressure differential and pulls in more fuel. For effective, consistent, powerful jetting... don't go bigger than your valve head.
cyclerider57 said:don't go bigger than your valve head.[/FONT][/FONT]
Well damneet, I've got a 23mm!
I guess I might have to reconsider the BVH.
it is one of the geuine 138ccs w,the bvh.it hauls a$$ with a junk 22mm carb so i figured it would really scream with a nice 26mm. turns out...not so muchsibo said:So, by 138 is that one of the misstamped 128s? Still, I'd think that's enough to use a 26er, the valves should be way bigger than my GPX.
Well, WTFWheelspeed831 said:it is one of the geuine 138ccs w,the bvh.it hauls a$$ with a junk 22mm carb so i figured it would really scream with a nice 26mm. turns out...not so much
Is it crap all over or just the low end pilot range?
1 - 20 of 24 Posts
- This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
PlanetMinis Forums
PlanetMinis forum is the internet's largest mini bike community. View thousands of photos, event coverage, tips, tricks and performance mods.
Full Forum Listing
Top Contributors this Month
View All
Dr. Frankenstein
24 Replies
davmo
10 Replies
Carlo C.
9 Replies
