For Those about to Rock... buying OKO Flatslides..

[pbk]

^^^ yer its JJH

update on my carb i sealed the top as i found that the sivel brass piece lets air in and aslo where the cable goes in so i sealed that off and thought i would try the e clip up a notch on the needle when i started it cold it sounded alot better and seemed to rev out nicely once it warmed off and i took choke off it was worse than before so im thinking of putting the e clip down one notch from middle and see where that goes.
i have some jets coming tomorrow a k40 slow and a 104 main as i have read up on the thread below that most people seem to be running this combination with the lifan 150. http://www.miniriders.com.au/tech-talk/19731-carby-my-lifan-150cc-4.html

thump 140 are you running a lifan 140 in yours as this would make sense why your 140 likes the smaller jets but i will see how the bigger jets go and i will have a fiddle.i also turned the mixture in and when iddling and did not change note of engine and i was able to wind it all the way in and did nothing so i wond it out 1 and a half turns

 

[linkenator]

hi thump*140 grate thread
i have been reading the thread and have become very keen on
an oko 28mm carby. i am just curious if any work needs to be done to where the manifold that comes with the carby is bolted to the engine or it will just bolt on.
cheers
Davo

 

[thump*140]

Ok for you chaps following this thread and tuning your own flatslides, got off my buttocks and checked the jetting on mine. Dont take this as gospel, as your bike will no doubt be different, but my Lifan 140, with IRK, Cam, ported manifold and head, and Big Bore pipe is running a K39 pilot jet, a #100 main jet, needle is on the second clip from the bottom, and the air screw is 1.5 turns out.
This should give you a starting point. If your motor is stock, try a K36 pilot, and #95 main..
Hmm.. probably should make that my avatar/signature... "TRY A #95 MAIN"... ha ha

 

[pbk]

*UPDATE*

moved the e clip down a notch from the middle and runs alot better actually rideable now and has so much for pull at the top end indeed these carbs ARE NOT for the inexperienced i nearly flipped several wheelies and my bike does not have any hestitaion popping on the back wheel in 3rd.
my bottom end of power is still a bit crap but i think the bigger slow jet will help.

does anyone know what the size number of jets actually mean like does it 0.36mm say for a size 36 jet??? because im thinking of maybe slightly drilling out my slow jet and see if it helps at all.

 

[MarlboroMan]

Hello thump*140 can you tell me what is in your mind on puting an OKO 26mm on the 250 bliz? Why did you put a larger carb on a 140cc and small in 250cc?
Oko have 28 and 30mm, and koso have the same carb in 32mm.
Can you tell me what jetings did you use on the koso 26mm for the bliz? did you change the air filter for one from Uni filters? What have you done more on the engine,to get more power?

Best regards

 

[pbk]

*update*

fuel bowl was low so i bent theur screw out anot little tabe and made a little bit higher and turned the fuel mixther half still yet to make it better in the bottom but i am getting very close well do some more work tomorrow as it is getting too late now to be runnig the bike as the neibours get a bit narky with you

 

[thump*140]

hi thump*140 grate thread
i have been reading the thread and have become very keen on
an oko 28mm carby. i am just curious if any work needs to be done to where the manifold that comes with the carby is bolted to the engine or it will just bolt on.
cheers
Davo

Hi Linkenator
I wouldnt recommend the 28mm unless you have either a: a relatively highly modified 140cc engine or bigger, and b: you know how to tune carbies, or have access to a good bike dyno shop...
if you have either of the above, go for it, the performance rewards are well worth it... I'd go for the 24 or 26mm if you have a smaller, or standard engine. much easier to tune, and they will actually offer a better performance increase than what the 28mm does... (140 or below just isnt a big enough motor to be useful matched with the size and capability of the 28mm in regards to fuel/air flow)
In short, i'd go with the 26...
All of the OKO flatslides seem to be supplied with all the gear you need for it to literally be a bolt on plug-and-play item. No mods to the manifolds etc are necessary.

Marlboro Man: I ordered the 26mm to go on the blitz, mostly due to the fact they are easier to tune, and the new 26's have one less air-port... one less thing to worry about. The air port, is some vent next to the choke button. I'm not entirely certain what it does, but it may be some sort of "re-breather" for diverting crankcase gases back to the carby.. i simply blocked mine off on the 140.
The other reason is, when i got the 28mm for the 140, i didnt have a great deal of experience with carbies on minibikes, and thought bigger would be better. In my case it was, due to the amount of mods on my 140, but it took a long time to get the performance right.
So far the 26mm seems great on the Blitz, and has got rid of the top end "dead-zone" on the GEN 3 loncin 250 motor.
as far as jetting goes, i'm running a K40 pilot, Needle jet on the middle clip, and a #97 main jet... TAKE NOTE KIDDIES TUNING THEIR OKOS... A 250cc MOTOR TUNED WELL WITH A #97 MAIN JET.... I used the standard air filter that came with the carby, as space is at a MASSIVE premium until i can find a suitably sized pipe to refit the original airbox.

PitbikeKid: HOW F***** AWESOME IS THE TOP END WITH THESE CARBIES???!!!! Heh heh...

 

[Brocko]

The mixture screw.. Is this the one that is up under the carb on the engine side of the carb that has a small hole that you screw it up into?? Like by winding it out it opens up that tiny hole in the intake??

 

[thump*140]

The mixture screw.. Is this the one that is up under the carb on the engine side of the carb that has a small hole that you screw it up into?? Like by winding it out it opens up that tiny hole in the intake??

on a mikuni, yes. it's under the carby throat on the intake (engine) side.
On an OKO its right next to the idle adjusting screw.
Not sure about the Molkt carbies.
am guessing you have a mikuni?

 

[daimojay]

molkt mixture is also next to idle.

 

[pbk]

damm i love these carbys so much the power up top is so good and its so much easier to hold your revs through a sandy berm ive got some jets coming so i might be able to fix the bottom end a little but otherwise wont worry about it seeing as i usually stay on top of the revs.....
i cant really see myself using a different carb other than these

 

[thump*140]

damm i love these carbys so much the power up top is so good and its so much easier to hold your revs through a sandy berm ive got some jets coming so i might be able to fix the bottom end a little but otherwise wont worry about it seeing as i usually stay on top of the revs.....
i cant really see myself using a different carb other than these

Yeah they're an addictive little carby once you get em running right. I never managed to get mine perfect on the pilot... seems to be that you can have either the pilot tuned right, or the main jet... obviously, the main is the one to have perfect, as for poor bottom end jetting on the pilot, well, that's what the clutch is for... ha ha..
If you dont have an IRK on your bike, consider it. And a hydraulic clutch... they really help bring the motor alive when added to the Flatslide.
The top-end performance of these carbies is why i chose one for my Blitz... The Gen 3 Loncin is great until you have it tapped. then it is gay. Gen 3 + Flatslide =

Great carby for supermotard bikes that spend most of their time screaming... would love to have a registered motovert... throw in a dialled 140 or 150, add a flatslide... beat traffic...
hmm.. getting off topic..

 

[Brocko]

Yer i have a mikuni.. Its a bitch it being under there.. Was thinking i could just use a flat head bit to adjust it tho..

 

[pbk]

yer my lifan 150 runs an ORK and it seems to be good never ran a an IRK before but i am definately considering the hydraulic clutch as ive seen them for like 40 bucks on ebay

 

[linkenator]

i'm going to buy a 26mm oko flatside race carb from dhz
i got a 32mm bigbore exhaust and hydraulic clutch on the way from the states and
was just wondering if u got any advice for jetting coz i got a choice of two jet kits
:slow 39,40 Main: 98, 100
Slow 36,37,38 main 98 100
this is my choice of two starting kits for jetting
any advice is much apreciated
cheers Davo

 

[pbk]

dont buy a jet kit yet as may not need it

 

[thump*140]

i'm going to buy a 26mm oko flatside race carb from dhz
i got a 32mm bigbore exhaust and hydraulic clutch on the way from the states and
was just wondering if u got any advice for jetting coz i got a choice of two jet kits
:slow 39,40 Main: 98, 100
Slow 36,37,38 main 98 100
this is my choice of two starting kits for jetting
any advice is much apreciated
cheers Davo

Hmm.. tricky call... given the fact that the OKO's come supplied with pretty much whatever they can find to put in there, i'd perhaps grab the second jet you mentioned, depending on affordability.. if you can afford to have them, they'll come in handy.. the second kit has a better range of pilots, and the mains are pretty close to what you'll need to at least get the thing running well enough to tune it properly..
with the mods you've quoted, and assuming you have a 140 or above, you should be pretty right with the jets you've mentioned. perhaps open the carby up as soon as you get it, check your jets, and if they're bigger than a K39 pilot, and bigger than a #100 main, put the smallest ones you have in the jet kit, and go from there.
Good Luck!! you'll be quite massively stoked with the performance once you get these bits bolted on.

 

[linkenator]

cheers thump

 

[nicko451]

if tuned right the flatside will give the engine an increase in power!

 

[thump*140]

^^^^you never know, it just might..
but only if you hold your head sideways on a bit of a tilt when you twist the throttle... heh heh