Mikuni Carb Install Question

Johnp · 05-26-2016, 02:01 PM

After reading through all the Carb threads from everyone, I bought the carb recommended by newrider and I think a few others on ebay:
http://www.ebay.com/itm/360100626734

I've also seen everyone talking about the jets, so I ordered this 25 pilot jet (which I now suspect is the wrong one):
http://amzn.to/1TGWYMu

And this set of main jets:
http://amzn.to/249ycr2

There's just one problem. Has ANYONE done any sort of guide to swapping in a Mikuni? And Motocheez's vid about tuning his carb ain't going to cut it. So does anyone have any suggestions?

So many questions...

I opened the bowl on the carb and do I have these labeled correctly?

Does it appear that it comes stock with a 100 main and 20 pilot?

Am I supposed to just use a flat head screwdriver to unscrew the existing jets and then screw in the new 25/110 jets? How much/tight should they be screwed in?

The 25 Pilot jet I bought doesn't look anything like the one in the photo. It's smaller with holes on the side and has no slot for screwing it in. Is that the wrong one? Can anyone give me a link on Amazon to the right one?

I was going to order an idle adjuster screw from eBay or Amazon, but I don't know which would work. Any suggestions?

I keep seeing Mikuni carbs with numbers like VM22, VM24, VM32, VM34, HSR45, etc. I assume those are model numbers? What model number is ours?!? It wasn't on the eBay listing and I can't find it anywhere.

That should be enough to get started... Anxiously awaiting you guys to rescue me from my idiocracy (which was a great movie BTW).

ughmas · 05-26-2016, 02:21 PM

this tutorial on the Keima carb for the TT250 should answer the questions about removing and tightening the jets, I believe it is similar to the mikuni.

https://www.cscmotorcycles.com/Articles.asp?ID=294

As far as your other questions, someone with a mikuni will probably have to field

Bruce's · 05-26-2016, 02:52 PM

Most of the cheap mikuni carbs on ebay are fakes ,so no surprise the jets do not look the same ,but they should work .You can use a screwdriver ,but I tend to use a wrench or socket on the main .When you loosen them off ,you will see how tight they need to be ,snug is fine .The model number is vm30 ,if your new carb is in fact a 30 mm carb ,but honestly chances are it's a knock off .

Sport Rider · 05-26-2016, 03:13 PM

to my knowledge, you'll want a VM26 model that is 30mm. while it doesn't specify the one you have is a VM26, from the ebay site, it looks right. you have the pilot and main labeled correctly. I used screwdriver on mine. just snug it down but don't try to over torque it. You may still be running a bit lean with the 25/110 you are thinking about. most of us start with a 30/115.

also note the pilot screw which is at the bottom of your first picture. you should start with that at 1.5 turns out and adjust from there as needed.

lastly, remove the top and adjust your needle to the second clip. you might even try 3rd clip since you're running a bit smaller jets than I have.

after you get it running, post more info about how it's performing for you and perhaps we can assist you with a bit of finer tuning.

if you have not done too much work on carbs before (like me), you will find this site helpful.
http://www.iwt.com.au/mikunicarb.htm

Azhule · 05-26-2016, 05:30 PM

http://www.jetsrus.com/a_jets_by_car...-486_pilot.htm

??

Those are what fit in my VM26 "30mm Mikuni Carb", check the size of your pilot jet to make sure its the right size before ordering any more jets

If that slow jet is what you need they can be had for about 90 cents when bought in a 12 pack on eBay or Aliexpress (I'm not good with those other sites just yet

)

http://www.aliexpress.com/item/Modif...243554212.html

Bruce's · 05-26-2016, 06:27 PM

Where are you guys getting this vm26 -30 mm carb stuff ?a true vm26 is a 26 mm carb ,the vm30 is a 30 mm carb .

Johnp · 05-26-2016, 07:26 PM

Quote:

Originally Posted by Azhule

http://www.jetsrus.com/a_jets_by_car...-486_pilot.htm

??

Those are what fit in my VM26 "30mm Mikuni Carb", check the size of your pilot jet to make sure its the right size before ordering any more jets

Thanks for the link. I believe I found them on Amazon!

And thanks for the size correction SportRider. I'll start with the 30/115. And I'll brush up on the link you posted.

Azhule · 05-26-2016, 08:24 PM

Quote:

Originally Posted by Bruce's

Where are you guys getting this vm26 -30 mm carb stuff ?

I got those names/numbers from the place I bought it from ("Generic Mikuni 30mm VM26 Carburetor" was on my invoice) and I also got it off the carburetor by looking at it and by doing some measurements with a digital caliper

Bruce's · 05-26-2016, 09:12 PM

Ok ,the 29.90 measurement is not the carb size ,the carb is measured in the Venturi ,if you removed the slide it's the area at the bottom .From the Venturi ,the carb body tapers outward to get your 30 mm measurement .We are just splitting hairs here ,your carbs are 26 mm according to the sellers info ,there is no reason they list and show the 29.9 measurement because all vm26 carbs have the same taper .

hertz9753 · 05-26-2016, 10:05 PM

Like that?

Azhule · 05-26-2016, 10:32 PM

Again

I just list what the seller I bought mine from said in the description, everyone on this forum is calling them the same thing "30mm or VM26 Mukini Clones"

I have always had it listed as a VM26 in my sig... Like I said... from MY measurements I listed it as what I thought I received (a "26mm Venturi")

Sport Rider · 05-28-2016, 09:42 AM

Quote:

Originally Posted by Bruce's

Ok ,the 29.90 measurement is not the carb size ,the carb is measured in the Venturi ,if you removed the slide it's the area at the bottom .From the Venturi ,the carb body tapers outward to get your 30 mm measurement .We are just splitting hairs here ,your carbs are 26 mm according to the sellers info ,there is no reason they list and show the 29.9 measurement because all vm26 carbs have the same taper .

good to know as I'm not an expert with carbs. I always referenced the 30mm because it's what the opening on the motor is. I didn't realize all VM26s have a 30 mm opening.

Weldangrind · 05-29-2016, 09:47 PM

Whatever they should be called, I've installed several of the "30mm Mikuni" carbs from eBay and had excellent results from them all. The castings have been flawless, and the jets have been very easy to find. That said, I don't buy jets very often anymore, I just drill 'em out. Once I find a size that works, I write it on the bowl with a Sharpie.

dpl096 · 05-30-2016, 12:31 AM

Quote:

Originally Posted by Weldangrind

Whatever they should be called, I've installed several of the "30mm Mikuni" carbs from eBay and had excellent results from them all. The castings have been flawless, and the jets have been very easy to find. That said, I don't buy jets very often anymore, I just drill 'em out. Once I find a size that works, I write it on the bowl with a Sharpie.

Great tip. . thanx!

05-26-2016, 02:01 PM	#1
Johnp Join Date: Apr 2016 Location: Dallas, TX Posts: 65	Mikuni Carb Install Question After reading through all the Carb threads from everyone, I bought the carb recommended by newrider and I think a few others on ebay: http://www.ebay.com/itm/360100626734 I've also seen everyone talking about the jets, so I ordered this 25 pilot jet (which I now suspect is the wrong one): http://amzn.to/1TGWYMu And this set of main jets: http://amzn.to/249ycr2 There's just one problem. Has ANYONE done any sort of guide to swapping in a Mikuni? And Motocheez's vid about tuning his carb ain't going to cut it. So does anyone have any suggestions? So many questions... I opened the bowl on the carb and do I have these labeled correctly? Does it appear that it comes stock with a 100 main and 20 pilot? Am I supposed to just use a flat head screwdriver to unscrew the existing jets and then screw in the new 25/110 jets? How much/tight should they be screwed in? The 25 Pilot jet I bought doesn't look anything like the one in the photo. It's smaller with holes on the side and has no slot for screwing it in. Is that the wrong one? Can anyone give me a link on Amazon to the right one? I was going to order an idle adjuster screw from eBay or Amazon, but I don't know which would work. Any suggestions? I keep seeing Mikuni carbs with numbers like VM22, VM24, VM32, VM34, HSR45, etc. I assume those are model numbers? What model number is ours?!? It wasn't on the eBay listing and I can't find it anywhere. That should be enough to get started... Anxiously awaiting you guys to rescue me from my idiocracy (which was a great movie BTW). __________________ John P. 2016 Hawk 250 - Black All my mods are documented on my Blog! My Blog \| Google+ \| Twitter \| Facebook
	0

05-26-2016, 02:21 PM	#2
ughmas Join Date: Feb 2016 Location: NY Posts: 172	this tutorial on the Keima carb for the TT250 should answer the questions about removing and tightening the jets, I believe it is similar to the mikuni. https://www.cscmotorcycles.com/Articles.asp?ID=294 As far as your other questions, someone with a mikuni will probably have to field __________________ 2005 CBR600RR 2016 CSC TT250 Coming Soon
	1

05-26-2016, 05:30 PM	#5
Azhule Join Date: Dec 2015 Location: CO Posts: 1,525	http://www.jetsrus.com/a_jets_by_car...-486_pilot.htm ?? Those are what fit in my VM26 "30mm Mikuni Carb", check the size of your pilot jet to make sure its the right size before ordering any more jets If that slow jet is what you need they can be had for about 90 cents when bought in a 12 pack on eBay or Aliexpress (I'm not good with those other sites just yet ) http://www.aliexpress.com/item/Modif...243554212.html __________________ "Think as you like... but this self proclaimed Professor is always right" - Buckshot "You never know what someone is hiding beneath their smile..." - NinjaTom - R.I.P.
	1

05-26-2016, 10:32 PM	#11
Azhule Join Date: Dec 2015 Location: CO Posts: 1,525	Again I just list what the seller I bought mine from said in the description, everyone on this forum is calling them the same thing "30mm or VM26 Mukini Clones" I have always had it listed as a VM26 in my sig... Like I said... from MY measurements I listed it as what I thought I received (a "26mm Venturi") __________________ "Think as you like... but this self proclaimed Professor is always right" - Buckshot "You never know what someone is hiding beneath their smile..." - NinjaTom - R.I.P.
	0

05-29-2016, 09:47 PM	#13
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	Whatever they should be called, I've installed several of the "30mm Mikuni" carbs from eBay and had excellent results from them all. The castings have been flawless, and the jets have been very easy to find. That said, I don't buy jets very often anymore, I just drill 'em out. Once I find a size that works, I write it on the bowl with a Sharpie. __________________ 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
	1

05-26-2016, 02:52 PM	#3
Bruce's Join Date: Apr 2015 Location: Sudbury ,Ontario Posts: 855	Most of the cheap mikuni carbs on ebay are fakes ,so no surprise the jets do not look the same ,but they should work .You can use a screwdriver ,but I tend to use a wrench or socket on the main .When you loosen them off ,you will see how tight they need to be ,snug is fine .The model number is vm30 ,if your new carb is in fact a 30 mm carb ,but honestly chances are it's a knock off .
	0

05-26-2016, 03:13 PM	#4
Sport Rider Join Date: Jan 2016 Location: Mooresville NC Posts: 2,051	to my knowledge, you'll want a VM26 model that is 30mm. while it doesn't specify the one you have is a VM26, from the ebay site, it looks right. you have the pilot and main labeled correctly. I used screwdriver on mine. just snug it down but don't try to over torque it. You may still be running a bit lean with the 25/110 you are thinking about. most of us start with a 30/115. also note the pilot screw which is at the bottom of your first picture. you should start with that at 1.5 turns out and adjust from there as needed. lastly, remove the top and adjust your needle to the second clip. you might even try 3rd clip since you're running a bit smaller jets than I have. after you get it running, post more info about how it's performing for you and perhaps we can assist you with a bit of finer tuning. if you have not done too much work on carbs before (like me), you will find this site helpful. http://www.iwt.com.au/mikunicarb.htm
	2

05-26-2016, 06:27 PM	#6
Bruce's Join Date: Apr 2015 Location: Sudbury ,Ontario Posts: 855	Where are you guys getting this vm26 -30 mm carb stuff ?a true vm26 is a 26 mm carb ,the vm30 is a 30 mm carb .
	0

05-26-2016, 09:12 PM	#9
Bruce's Join Date: Apr 2015 Location: Sudbury ,Ontario Posts: 855	Ok ,the 29.90 measurement is not the carb size ,the carb is measured in the Venturi ,if you removed the slide it's the area at the bottom .From the Venturi ,the carb body tapers outward to get your 30 mm measurement .We are just splitting hairs here ,your carbs are 26 mm according to the sellers info ,there is no reason they list and show the 29.9 measurement because all vm26 carbs have the same taper .
	0