Nibbi Racing PE30.

[Megadan]

The 120 is lean on mine as well, but it is on the safe side of lean and pulls very strong. As long as the temps stay on the hot side, over 80, it should be just fine. I have a 122 on the way though. The trickier challenge is going to be the slide spring. I am thinking I might try the pwk spring inside the PE30 spring to see how it feels. If that is too stiff I may just try and stretch the PE spring a little bit.

[JerryHawk250]

Are you having any problems with the cable binding?

[Megadan]

Originally Posted by JerryHawk250

Are you having any problems with the cable binding?

Nah, cable is fine. The spring on this carb is very light, almost half the rate of the pz30. Feels like almost no resistance at the throttle tube.

[JerryHawk250]

Originally Posted by Megadan

Nah, cable is fine. The spring on this carb is very light, almost half the rate of the pz30. Feels like almost no resistance at the throttle tube.

Will the one off your PZ30 fit?

[Megadan]

Originally Posted by JerryHawk250

Will the one off your PZ30 fit?

Nope, too short lol Just experimenting with ideas. I have some mikuni VM parts laying around, so I might see if a VM30/32 spring is similar in size. If not, like I said, I can always give the spring a bit of a stretch.

[Wild Dog]

Why not a spring from a genuine Kehin PE30???
http://www.keihincarbs.com/carbs/pe/gate.html

[Megadan]

Originally Posted by Wild Dog

Why not a spring from a genuine Kehin PE30???
http://www.keihincarbs.com/carbs/pe/gate.html

Thats my last resort lol. I have boxes of carburetors and parts, so if I have something on hand that will work, why spend more money?

[G2ic22]

So i finally got nibbi installed tonight and I can tell once I dial it in it's going to be one raped ape!!! Wants to bog out though from anywhere after about quarter throttle. Needle on notch 4 and have 38 pilot with 118 main. Seems really strong right off idle but soon bogs thereafter. Does ok when ease throttle but still no go. Think need to drop needle to 5 and go bigger main. Plug looked brown and dry so not rich I don't think. Plug could been that way from previous carb but didnt turn black from my short spin and to dark to see any black smoke but first thing in the AM I'm going to try dial it in didnt want to piss off the neighbors haha but she sure has a even meaner grunt with the nibbi sounds like a I remember a yz450 just plain mean and I absolutely gone ape shit!!!!

[G2ic22]

Well the nibbi sure is a finicky carb to tune I'll say that. I had a few issues today spent most of the day on it. One thing the throttle spring as you stated Megadan is way to soft and had me chasing the wrong jets most the day. The slide as you said sticks open and didnt close all the time causing idle to be high when stuck from vacum not letting it seat. After switching spring from the vm26 which actually fit in the cup of the cap and perfectly to the black spring seat in the carb. After having the stiffer spring then I could finally make so leeway. The carb is extra sensitive as stated to even the slightest adjustments to the air screw and idle screw. So the weird thing is the power is inconsistent and what I mean is when take off from idle full throttle giving her all shes got through few gears it screams and gas great power but slow down and try again within a few second go bang through the fears again it doesnt have same power it comes out flat. It's like it takes all the fuel the first go around and half to slow down and putt for a second then hit it and it screams through gears but if you bang through the gears at WOT slow down and hit WOT again to quick it just doesnt have the same pull as the first time unless let off. It's almost like you half to wait for the fuel to load back up like it drains the carb and needs to fill back up to hit it again and get same power. I checked the float and even made it to get more before float closes the valve but same thing. It doesnt really bog out or miss it just needs like time to re fuel or recharge for a minute to get the same power response otherwise it's just wont pull hard if you continuously try to let her RIPP. Plug is good and brown with little black it's not Rich. I have 128 main anything lower makes it worse and the 130 Boggs out. Needle has to be on 1st notch anything after will make it cut out from quarter throttle. Its dialed in pritty good but csnt for the life of me see why it will pull real hard for one pull but dont let off the gas and try keep giving it hell it starts to lose power but let it load back up and take off it pulls really hard.

[Megadan]

I would wager a guess that you are still too rich on the pilot circuit. I could never get a 38 to idle correctly and it still had issues with fuel surging and pooling at idle, which would then cause a bog once it transitioned to the needle jet. Your scenario with the blast through gears, let off, then blast again sounds to me like the vacuum draw when you let off the throttle combined with the very rich pilot jet is causing a buildup of fuel in the intake that then becomes a big rich wave of fuel when you try to open the throttle again. This would also explain why your needle is maxed out in the leanest position. I have been able to run the needle in the 4th notch even on 122 main jet, but it starts to get a bit too rich on a 125 or larger.

Setup is a 35 pilot, 135 main, 1 7/8 turns out on the mixture screw. needle in center slot.

[Douglass]

As I sit right now I have a 35 pilot, 1 7/8 turns on the mixture screw, needle in the center slot, and currently I am back on a 125 main, which while a touch rich when the temps climb past 90, works better once it cools down a bit into the 70-80's temp range.

Dan, could you provide the jet types for this carb?

Will any of these work?

https://www.rockymountainatvmc.com/search/go?w=jets

I would also like to clarify the air/fuel adjustment. My understanding is on the four stroke carbs when I am turning the screw counter clock wise I am creating a more rich A/F ratio, or allowing more fuel at idle. Is this correct?

[Megadan]

Originally Posted by Douglass

Dan, could you provide the jet types for this carb?

Will any of these work?

https://www.rockymountainatvmc.com/search/go?w=jets

I would also like to clarify the air/fuel adjustment. My understanding is on the four stroke carbs when I am turning the screw counter clock wise I am creating a more rich A/F ratio, or allowing more fuel at idle. Is this correct?

Pilot is an N424-21. Main is a 99101-393

The idle mixture adjustment on these carbs is an air screw. The more you open it (counter clockwise) the more air you let through and the leaner the mixture. On the stock carbs it is a fuel screw, and thus opposite.

[Douglass]

The idle mixture adjustment on these carbs is an air screw. The more you open it (counter clockwise) the more air you let through and the leaner the mixture. On the stock carbs it is a fuel screw, and thus opposite.

Dan, thank you for confirming. One more question, is there a way to tell if a carburetor has an air or fuel screw?

Also, do you know if the stock air box intake boot would fit on the PE30, or is a new air filter required? The Apollo uses the same size stock carb as the Hawk, and I would like to retain the stock air box if possible.

Douglass

[Megadan]

Originally Posted by Douglass

Dan, thank you for confirming. One more question, is there a way to tell if a carburetor has an air or fuel screw?

Also, do you know if the stock air box intake boot would fit on the PE30, or is a new air filter required? The Apollo uses the same size stock carb as the Hawk, and I would like to retain the stock air box if possible.

Douglass

Way to tell is usually simple. if it is before the throttle slide it is an air screw. After the slide, fuel.

The stock boot would not work without adapting it somehow. you would have to make your own intake tube or run a pod