Which carby for my Lifan 150cc

[crazzy #1]

NEW OKO 26mm FLATSLIDE RACE CARBY KIT 140CC 150CC 160CC - eBay Other Makes, Bike Parts, Motorcycle Parts, Accessories, Cars, Bikes, Boats. (end time 17-Oct-08 20:00:00 AEST)

this is like your oko correct pb?

ive got a vm24 but want to go to a 26, seeing dhz is not too far from work ill be droping in to get one, but he has 4 26mm carbs

the one above and these three
NEW OKO VM26MM PERFORMANCE CARBY KIT 140CC 150CC - eBay Other Makes, Bike Parts, Motorcycle Parts, Accessories, Cars, Bikes, Boats. (end time 11-Nov-08 00:59:24 AEDST)

NEW MOLKT 26mm RACING CARBURETOR KIT 140CC 125CC LIFAN - eBay Other Makes, Bike Parts, Motorcycle Parts, Accessories, Cars, Bikes, Boats. (end time 09-Nov-08 19:10:43 AEDST)

GENUINE HONDA KEIHIN PE26 PERFORMANCE JAPAN CARBY - eBay Other Makes, Bike Parts, Motorcycle Parts, Accessories, Cars, Bikes, Boats. (end time 07-Nov-08 15:53:13 AEDST)

which would be the go?

 

[Cactus Jack]

The Kehin PE-26 should be the best quality carb as long as they have been set up at the factory for 4 strokes and have a perforated needle jet and not a non perforated two stroke needle jet ...

Take a set of verniers with you and measure the diameter of the venturi in FRONT of the slide as you can see in this pic ... http://i23.ebayimg.com/05/i/001/12/77/4809_10.JPG ... if it DOESN'T measure 26 mm in diameter all around then the carb is NOT a 26 mm carb ... (how big does a 55 mm bore measure all the way from top to bottom ?? ... how big should a 12 inch Johnson measure when compared to a 12 inch ruler ?? ) ... and don't listen to any arguments otherwise ...

In the US they say that the OKO round slide 26's are really easy to tune ...

Flat slide carbs are supposed to give better bottom end and midrange response ... that's why CRF/YZF/KXF/RMZ etc run them ... only they run the accelerator pump models ...

 

[I_THUMP]

Flat slide carbs are supposed to give better bottom end and midrange response ... that's why CRF/YZF/KXF/RMZ etc run them ... only they run the accelerator pump models ...

You said ''supposed to'' so does that mean that you dont think flat slides would give any better bottom end or mid range response?

 

[themountain]

They are a major headache to tune...thats for sure!!

Hey Jack...since when got keihin a PE26...??? I can´t find it in their catalog....must been one for 4cyl. engines...??

 

[Cactus Jack]

Who knows ?? A lot of places reckon they have them ... and they're supposed to come stock on a 2000 model KX100 ...

KX lOO FEATURES - - Dirtbike at Off-Road.com

::KAWA+H!GASH!YAMA::å°å·ãƒ’ガシヤマã®ãƒ–ãƒ*ã‚° - KEIHIN PE26化油器

I bought what was supposed to be a PE-26 off ebay and when it got here the venturi measured 28 mm ... It's the model that has a stupid cable operated choke ... but you can buy the hand operated pull choke to suit ...

I-Thump ... I'd assume the flat slide carbs would have to have the bottom end advantages they're claimed to have (but mainly when used on a 2 stroke) , otherwise it'd be a waste of time manufacturing them ... The fact that MX 4 strokes have flat slide carbs with accelerator pumps and most people talk about a bog or stumble with non pumper OKO's and other carbs puts doubt into my head since I haven't gotten around to experimenting with the various carbs I've got on horizontal motors ...

'Nowhere near where we live to do testing and tuning without being charged exorbitant fees by blokes in light blue shirts and dark blue pants driving fancy looking cars with red and blue lights on top ...

 

[crazzy #1]

i ended up getting a VM26 OKO with the clear bowl

NEW OKO VM26MM PERFORMANCE CARBY KIT 140CC 150CC - eBay Other Makes, Bike Parts, Motorcycle Parts, Accessories, Cars, Bikes, Boats. (end time 11-Nov-08 00:59:24 AEDST)

seems okay, but needs sorting! depends on where the air mixture screw is but no matter what i cant get it to run hesitant free! and at $4 a pop i wasnt going to buy a whole heap off jets not knowing what the carb actually went like!

 

[pb performance]

@ Crazzy #1

Yeah thats the same as the one I got !! I got mine from MSO, It included 10 pilot and 10 main jets for $108 delivered... It then cost me $28 for the adapter from DHZ... and $62 for a 50mm Uni filter and 1lt of Motul filter oil...

All in all it's runnin sweet now so all good....

 

[jakey]

I just put a 150 Lifan in a mates bike and I took your advice and told him to get a VM26 Mikuni which he did and bolted it straight on. It runs great straight out of the box with no hassle so he is as happy as a priest in a room full of alter boys (sorry to all the catholics, no offence intended).

lmao haha funnyest thing all day bit harsh tho

 

[Mack]

For the 26 oko heres what I do.

Pull the entire carb apart. Very simple. Including the jet housing. Just two screws and it lifts out to reveal the drillings underneath. Basically I ensure the drillings are accurate and clear of castings, sharp internal bends are cleaned up. Also the exit points into the carby throat is cleaned up. Imagine this area as like the nozzle on a spray bottle or can. If it is not perfectly round or has castings sticking out it will not spray evenly. This I find is the first step to stabilise the idle and snap off the bottom. I am running the biggest cams I can and in theory the engine should stumble at idle and quarter throttle a bit because of the disturbed intake flow and reduced vaccuum, but it don't. By sticking with the 26mm over a 28mm carb, you are helping this also.
BUT we want a BIG top end aswell don't we? Really a 28mm is better at this
end of things on a worked 150.
So we whack the carb upside down in a soft jaw vice and procede to open the top 2/3 of the carb throat out to 28+mm. I actually taper from the back of the carb being about 30-32 to about 28mm going past the slide and nicely blended at the manifold flange into the original 26mm and stay 26 all the way to the valve. I do not touch the bottom 1/3 of the carb except to put a 80 grit surface from the slide on. Prior to the slide I polish.

Have had great success with this carb. Can slam that throttle from any position anywhere, at any rev, it does not miss a beat. many instances the stock jetting on a DHZ carb is just right once cleaned up this way. I run a slightly fatter taper on the needle to rich the mid a tad and thats it. There is no limit to the top end, it will overrev in an instant and just keep on going till destruction. You must control the throttle.The only comment I get is about the top end wanting to keep pulling really hard and without warning. It feels like it wants to run on into corners a bit and is scary for some. It does this if you let the throttle cable get a little slack and unresponsive. This should be your very next mod. Fix the china throttle so its light and totally responsive. Most I have to redrill the cable hole back a bit to take up the slack. Use a hack saw to recut cable groove.

 

[crazzy #1]

i paid $100 for carb, cable, adapter and uni-filter i guess thats what happens when you buy 3 bikes + parts from the bloke and tend to pay in cash

 

[numroe]

Can slam that throttle from any position anywhere, at any rev, it does not miss a beat. many instances the stock jetting on a DHZ carb is just right once cleaned up this way.

That sounds familiar. The usage and the jetting. Nice post. Thanks Mack.

If my OKO26 flat died, I'd get another, and probably have to do what your wrote. Maybe got lucky with my current one. Interesting you mentioned the throttle. About 6 months ago I put on a domino throttle for better feel and I love it.

 

[Cactus Jack]

Yes ... a great informative post from Mack ... ... It's good to hear from ya' ... I'll save the info for when I go over my 26 and 28 OKO flatslides ...

 

[themountain]

For the 26 oko heres what I do.

.....

Wow...the MAN is alive!!
Nice writeup, hope you be around now more often!!

 

[crazzy #1]

okay, so i had a closer look at the carb i bought... okay pulled it apart and examined the carb! the castings are considerably good and there is no roughness as far as the eye could see im not going to touch as i do not want to turn a considerably good carb into something that dosnt work! seeing my bike is a bit boggy bottom end and could do with a bit more fuel flow top end i thought id have a look at the jets! there clean so no issue there! its running a k36, k97 combo which points out my issues! unfortunately i dont have any jets on had so ill have to pick some up during the week

what im thinking is picking up a k40, k100 and k105 and hopefully make a good combo! ive heard of people using k40 and k105 (as i can remember) on a 140cc donk

what are your thoughts for more people that have tried various jets

 

[pb performance]

Excellent Info MACK... Thank you for passing it on !!

 

[crazzy #1]

got myself k40, k102.5 and k105... still boggy bottom end but is much better up in the revs!

 

[Cactus Jack]

Here's some info on various different carbs ... Some people might want to add to it ... feel free to do so ... IF a rider is a quick throttle twister , then they might be better off with a 24 or 26 mm round bore carb that is modified (oval ported) as explained by Mack ... OR , getting a cammed throttle tube ... The absolute BEST solution would be to dial out for an accelerator pump carb ... There's a VERY good reason why they make 'em ...

MOLKT "26" round bore ..... measures 24 mm in diameter thru the venturi (24 mm either side of the slide) and tapers out to 26 mm out the rear of the carb ..... some sellers over here pass them off as "26" or "28" mm carbs ....

Mikuni VM-24 round bore (as shown in the new Dirtmax catalogue) ... measures 24 mm in diameter on the entry side and exit sides of the slide and tapers out to 28 mm out of the rear .....

The Molkt appears to be an almost identical copy of the Mikuni 24 except that it's made of lighter metal , has a 46 mm air filter flange and a bolt type manifold mount .... the Mikuni has a 43 mm air filter mount and a 35 mm round spigot for a rubber boot manifold adaptor .....

Mikuni 22 aka "25" oval bore .... measures 18 mm wide x 25 mm high thru the venturi which = about the area of a 22 mm round bore .... then it tapers out to 25 mm round out of the rear ....

OKO D-slide 26 round bore ..... measures 26 mm thru the venturi and is 26.5 mm in diameter out of the rear ....

OKO D-slide 28 round bore .... measures 28 mm thru the venturi but tapers to near 29 mm out of the rear ....

The MOLKT ..... has a tiny 3 mm I/D fuel inlet nozzle !!!!!!!! The 24 mm Mikuni has a 4.2 mm inlet nozzle .... OKO's are 4 mm .... Mikuni 22 is 3.8 mm ....

I also have a Miconi "26" which is near identical to the MOLKTS except that it has a 4 mm I/D fuel inlet nozzle .....

I have a Keihin PE-28 ? (TB-28) which was sold to me as a PE-26 ..... It's 28 mm thru the venturi and 29 mm out of the rear ...

And also a genuine VM-28 oval bore carb off a 1987 KX80 ..... the venturi is 32 mm high x 24 mm wide which = about 28 mm round in area .... the throat tapers out to 33 mm in diameter out of the rear .... it makes the MOLKT look tiny in comparison for a supposedly 2 mm smaller carb ....

Maybe someone can actually measure the venturi (I/D thru the slide) of their genuine Mikuni VM-26 round bore carb with proper inside calipers or inside mic to verify that they're a genuine 26 mm ???? ... Mountain ????? ... I'm curious to know if they're really a 26 mm throated carb or simply a 24 mm throated carb with a 26 mm butt hole ... I'd be really pissed off if I bought one and discovered they're not a true 26 ... and that would also explain why people say they are more responsive than a 26 mm throated carb ... I've hit the Yanks with that question and the silence is DEAFENING ...

 

[125riderz]

26mm mukini all my 125 lifan has and a new race cdi beats any factory 125 thumpsta

 

[Cactus Jack]

It appears that there's TWO different types of Mikuni VM-26 carbs ... There's the VM-26 606 which only has a 24 mm slide so it'd possibly only have a 22 mm venturi ...

And the VM26-8074 which has a 27.5 mm slide and could possibly have a 24 mm venturi since the 24 has the same sized slide ... The MOLKTS and MICONIS are almost identical copies of it ...

New VM Carburettors

 

[realmenride50s]

with my lifan150 i run oko26mil cab with main k105 k40 idel it goes very hard